bluuebunny/crossref_metadata_2025 huggingface dataset:
A Facile Synthesis of Nido-Carborane Polymers via Dynamic Self-Assembly by Poly(carboxybetaine methacrylate)
Authors: Wang Zhou
Published: May 2021

Carborane are widely applied in boron neutron capture therapy (BNCT) field, but it is difficult to perform biocompatibility with cells due to its own water solubility differences, so how to solve the water solubility problem has always been the focus of research. A simple, inexpensive
and effective method was used to study the synthesis of nido-carborane azaspirodecanium poly(carboxybetaine methacrylate) by one-pot cyclization of nido-carborane azaspirodecanium under the synergistic effect of inorganic bases and conventional organic solvents. Its characterization is mainly
to use 1H-NMR nuclear magnetic resonance spectrum and infrared spectroscopy to determine the characteristic peak and range of borane. Through transmission electron microscope (TEM), it can be observed that the white nanoparticles, namely carborane, are completely contained by polymer ions,
which not only increases the surface area but also the concentration of boron uptake in the cell is 100 times that of borono-phenylalanine (BPA). Based on the successful synthesis of N-CB5-4 and N-CB6-5 without harsh conditions, a feasibility point of view was put forward, namely, super water-soluble
carborane polymer.
Upshot of Concentration of Zirconium (IV) Oxynitrate Hexa Hydrate on Preparation and Analyses of Zirconium Oxide (ZrO2) Nanoparticles by Modified Co-Precipitation Method
Authors: Ramachandran M. , Subadevi R. , Rajkumar P. , Muthupradeepa R. , Yuvakkumar R. , Sivakumar M.
Published: May 2021

In the present work, pure nanocrystalline monoclinic Zirconia (ZrO2) has been successfully synthesized and optimized by the modified co-precipitation method. The concentration of raw material has been optimized with the fixed amount of precipitation agent (Potassium hydroxide
KOH). The thermal history of the precursor has been examined through TG/DTA analysis. All the samples are subjected to study the structure, fingerprints of the molecular vibrations, and morphology analyses. The representative sample has been analyzed through Transmission Electron Microscope
(TEM) and X-ray Photo Electron Spectroscopy (XPS) analyses. The as-prepared sample exhibits the better crystallinity and surface morphology with lesser particle size (190 nm) when the raw material concentration is 0.2 M. The as-prepared ZrO2 filler (0, 3, 6, 9, and 12 wt.%) is spread
through the enhanced polymer electrolyte P(S-MMA) (27 Wt.%)-LiClO4 (8 wt.%)-EC + PC (1;1 of 65 wt.%) complex system via solution casting method. The as-synthesized electrolyte films are examined via complex impedance analysis. P(S-MMA) (27 wt.%)-LiCIO4 (8 wt.%)-EC + PC
(1 ;1 of 65 wt.%)-6 wt.% of ZrO2 shows the high ionic conductivity 2.35 × 10–3 Scm–1. Temperature-dependent ionic conductivity studies obey the non-linear behavior. The enhanced ZrO2 has been expected to enhance the other electrochemical
properties of the lithium secondary battery.
Fe3O4@MCM@ZrCI2: A Practical Magnetic Mesoporous Zirconium-Based Nanocomposite as a Reusable Catalyst for the Synthesis of Spirooxindoles
Authors: Pourhasan-Kisomi Reyhaneh , Golshekan Mostafa , Shirini Farhad
Published: May 2021

In the present study, we aimed to investigate the catalytic role of the newly reported MCM-41 -based nanocomposite in which the low acidity of this mesoporous moiety was favourably improved via the stabilization of zirconium nanoparticles and was magnetized to make a facile work-up
procedure as an applicable and efficient method. The prepared Fe3O4@MCM-41 @ZrCI2 nanocomposite was successfully characterized using different analyses and then it was favourably exploited for the synthesis of spirooxindoles as the most prominent spiro compounds.
As predicted, Fe3O4@MCM- 41 @ZrCI2 showed considerable efficiency in the promotion of the studied reaction.
[ARTICLE WITHDRAWN] Semiconducting Polymer Dot-Based Ratiometric Fluorescence Nanoprobe for DNA Detection
Authors: Gong Zhen-Hu , Wei Zong-Nan , Liu Yi-Zhang , Xiao Lu-Fei
Published: May 2021

THIS ARTICLE WAS WITHDRAWN BY THE PUBLISHER IN MAY 2021
Outpatient Parotidectomy, a Safety and Financial Review
Authors: Scher Maxwell , Cabrera Claudia I. , Cai Yida , Tamaki Akina , Li Shawn , Fowler Nicole , Rezaee Rod , Lavertu Pierre , Teknos Theodoros , Thuener Jason
Published: May 2021

Objective:

The objective of this study is to investigate the safety, efficacy, and potential cost-savings of the outpatient parotidectomy procedure.

Methods:

This is a retrospective chart review of all patients who underwent a parotidectomy at a large academic center from 2015 through 2019 including demographic data, postoperative complications, drain placement, readmission, and financial cost. A comparison was performed between patients who underwent an outpatient vs inpatient parotidectomy.

Results:

A total of 335 patients underwent parotidectomy (136 outpatient; 199 inpatient). Comparison of patient demographics, common comorbidities, tumor size, tumor type, postoperative complications, and readmission rate was similar between the inpatient and outpatient cohorts. The overall mean cost difference between inpatient parotidectomy and outpatient parotidectomy for all years was $1528.58 (95%CI: $1139-$1916).

Conclusion:

The outpatient parotidectomy procedure has a comparable safety profile to the inpatient procedure while providing a significant cost-savings benefit.
rTMS for depression: The difficult transition from research to clinical practice
Authors: Amad Ali , Fovet Thomas
Published: May 2021

The publication of the 2020 Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for the management of mood disorders was followed by a series of correspondences discussing the place of repetitive transcranial magnetic stimulation (rTMS) in the sequence care for the routine treatment of depression. The controversy has led to an intense debate about the positioning of this neuromodulation technique in the clinical armamentarium for depression in the Australian and New Zealand Journal of Psychiatry. The many arguments presented by the authors to defend their respective points of view can be summarised in two main key issues: (i) the interpretation of the level of evidence of rTMS for depression and (ii) the characterisation of patients who could benefit from this treatment. In this viewpoint, we discuss the difficult transition from research to clinical practice regarding the use of rTMS to treat depression.
Capitalist Progress and Moral Economy: Sustaining Employment in India’s Handloom Sector
Authors: D’Costa Anthony P.
Published: May 2021

Capitalist progress implies the destruction of the old and uncompetitive sectors and the creation of new ones in their wake. However, in the Global South the loss of jobs in the older sectors is not necessarily offset by the new forms of employment. The objective of this paper is to critically examine how the vast employment in the Indian handloom sector could be sustained, given the competitive pressures from alternative technologies and products. Rather than allow the sector to be a victim of capitalist progress, this paper on moral economy grounds offers an alternative approach, which is to boost the demand for handloom products through commercial branding but one that is rooted in cultural valorization of artisanal craft. This strategy, complementary to state provisioning of subsidized inputs, comes at the expense of authenticity but is expected to enhance consumption and sustain livelihoods in the handloom sector.
Ready to Meet God? Faithfulness and the Death of a Loved One
Authors: Krull Douglas S.
Published: May 2021

Religiosity often predicts better adjustment after the death of a loved one, but findings vary. One source of variability could be the perceived faithfulness of the deceased. In study 1, more religious college students found the death of a hypothetical faithful person to be less sad than the death of a hypothetical unfaithful person, whereas less religious college students did not. In study 2, MTurk participants and highly religious Christians reported that the death of a faithful loved one was less difficult than the death of an unfaithful loved one, but the difference was greater for the highly religious Christians.
Between Post-Racial Ideology and Provincial Universalisms: Critical Race Theory, Decolonial Thought and COVID-19 in Britain
Authors: Meghji Ali , Niang Sophie Marie
Published: May 2021

This article looks at the British government’s handling of the first wave of the coronavirus pandemic. We argue that to analyse the government’s handling of this situation, we need to synergize insights from critical race theory (CRT) with decolonial thought. CRT shows how the pandemic has revealed and exacerbated racial inequalities within Britain, while these inequalities are then explained away through a post-racial ideology. Contrastingly, decolonial thought helps us to understand how Britain practises western and little Englander universalisms; neglecting other countries’ successful strategies of handling the pandemic, as they seek to pursue a ‘world-beating’ strategy to defeat the virus rather than help forge a global solidarity.
Modeling to predict thermal aging for flame-retardant fabrics considering thermal stability under fire exposure
Authors: Liu Xiaohan , Tian Miao , Wang Yunyi , Su Yun , Li Jun
Published: May 2021

The performance of firefighters’ clothing will deteriorate due to various exposures. Predicting its service life before decommissioning is essential to guide the use and maintenance of the uniform. The aim of this study is to introduce a model to predict the tensile strength of flame-retardant fabrics under fire exposure. The thermal degradation and microstructure of Kevlar/polybenzimidazole and polyimide/Kevlar fabrics were investigated. The decrease of tensile strength was attributed to the chemical changes and the development of microstructure cracks and charring of the fibers. Multiple linear regression (MLR) and artificial neural network (ANN) models were established to predict the tensile strength after thermal aging. The ANN model presented a better prediction result ( R2 = 0.88, root mean square error (RMSE) = 96.91) than the MLR method ( R2 = 0.76, RMSE = 138.61). The addition of fabric backside temperature ( T), glass transition temperature ( Tg), and degradation temperature ( Td) further increased the R2 (4%) and decreased the RMSE (14.99) of the ANN model, which was recommended as a prediction approach with better accuracy. The findings of this study will contribute to estimating the continuous performance of firefighting clothing.
Plasmonic silver nanoparticle-decorated electrospun nanofiber membrane for interfacial solar vapor generation
Authors: Liu Ye , Xiong Jian , Li Ailin , Wang Rongwu , Wang Liming , Qin Xiaohong
Published: May 2021

Interfacial solar vapor generation as an emerging technique has great potential in solving water shortage and pollution problems. Electrospun nanofiber membrane with high porosity, mechanical flexibility, numerous microsized channels for fast water transport, and low thermal conductivity offers an ideal platform for solar vapor generation. In this research work, plasmonic silver nanoparticles (Ag NPs) were utilized as photothermal materials and electrospun polyacrylonitrile (PAN) nanofiber membranes as substrates to fabricate Ag nanoparticles-uniformly decorated PAN (Ag@PAN) nanofiber membranes by electroless plating method. The morphology and chemical composition of the membranes were characterized by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffractometry. By varying the volume ratios of glucose and silver ammonia solution, the sizes of Ag NPs as well as the light-absorption ability of corresponding nanofiber membrane were regulated. As a result, the optimal Ag@PAN nanofiber membrane demonstrated a high light-absorption efficiency of 92.8% in the range of 280–2500 nm wavelength. The evaporation rate reached 1.34 kg m−2 h−1 and 5.83 kg m−2 h−1 under 1 sun and 5 sun irradiations, respectively. The plasmonic nanofiber membrane also exhibited long-term use stability, without any degradation in solar vapor generation performance even after 10 cycle tests. This work paves the way for the design and development of plasmonic nanofiber membranes as high-performance interfacial solar vapor generators.
Factors Associated with Victimization Experiences Among Juveniles Detained in a Chinese Correctional Facility: A Longitudinal Study
Authors: Wang Xinting , Zhao Jihong Solomon , Zhang Hongwei
Published: May 2021

Prison victimization constitutes a serious problem for organizations and individuals. It disrupts order in an institutional environment, and the experience of victimization can have a long-lasting psychological effect on incarcerated population, particularly juveniles. Relevant research suggests that the deprivation model and the importation model can help explain the occurrence of prison victimization. Using longitudinal data collected from a youth custodial facility in China, the current study examines factors that are believed to be predictors of prison victimization. Negative binomial regression, a commonly used tool for the analysis of prison victimization research using count data, is employed in the current study. The findings suggest that prior victimization experiences, reported record of violent delinquency, prison visitation, and demographics have significant impacts on in-prison victimization. The public policy implications of the findings are discussed at the end of the study.
Scale Alignment in the Between-Item Multidimensional Partial Credit Model
Authors: Feuerstahler Leah , Wilson Mark
Published: May 2021

In between-item multidimensional item response models, it is often desirable to compare individual latent trait estimates across dimensions. These comparisons are only justified if the model dimensions are scaled relative to each other. Traditionally, this scaling is done using approaches such as standardization—fixing the latent mean and standard deviation to 0 and 1 for all dimensions. However, approaches such as standardization do not guarantee that Rasch model properties hold across dimensions. Specifically, for between-item multidimensional Rasch family models, the unique ordering of items holds within dimensions, but not across dimensions. Previously, Feuerstahler and Wilson described the concept of scale alignment, which aims to enforce the unique ordering of items across dimensions by linearly transforming item parameters within dimensions. In this article, we extend the concept of scale alignment to the between-item multidimensional partial credit model and to models fit using incomplete data. We illustrate this method in the context of the Kindergarten Individual Development Survey (KIDS), a multidimensional survey of kindergarten readiness used in the state of Illinois. We also present simulation results that demonstrate the effectiveness of scale alignment in the context of polytomous item response models and missing data.
Graph Theory Approach to Detect Examinees Involved in Test Collusion
Authors: Belov Dmitry I. , Wollack James A.
Published: May 2021

Test collusion (TC) is sharing of test materials or answers to test questions before or during the test (important special case of TC is item preknowledge). Because of potentially large advantages for examinees involved, TC poses a serious threat to the validity of score interpretations. The proposed approach applies graph theory methodology to response similarity analyses for identifying groups of examinees involved in TC without using any knowledge about parts of test that were affected by TC. The approach supports different response similarity indices (specific to a particular type of TC) and different types of groups (connected components, cliques, or near-cliques). A comparison with an up-to-date method using real and simulated data is presented. Possible extensions and practical recommendations are given.
Responsible Leadership: A New Paradigm for Organizational Sustainability
Authors: James K. V. , Priyadarshini R. G.
Published: May 2021

Responsible leadership (RL) is becoming prominent and a new concept with growing interest as a creator of value-based relationships with all the stakeholders within and outside the organization. The traditional outlook of RL is where a leader was portrayed as a powerful individual demarcated significantly from the rest of others in the organization in terms of knowledge and capability. We emphasize the role of leadership that changed the business view from a shareholder concept to a wider relationship of all the stakeholders for economic, environmental and societal advancements. RL is built on an ethical framework and our approach towards the necessity of leadership is in terms of responsibility and accountability for organizational sustainability and overall development. Finally, a conceptual model is proposed on RL, describing the multiple dimensions leading to the outcomes in the changing business world.
Pharmacological strategies used to manage symptoms of patients dying of COVID-19: A rapid systematic review
Authors: Heath Laura , Carey Matthew , Lowney Aoife C , Harriss Eli , Miller Mary
Published: May 2021

Background:

COVID-19 has tragically resulted in over 2.5 million deaths globally. Despite this, there is a lack of research on how to care for patients dying of COVID-19, specifically pharmacological management of symptoms.

Aim:

The aim was to determine the dose ranges of pharmacological interventions commonly used to manage symptoms in adult patients dying of COVID-19, establish how effectiveness of these interventions was measured, and whether the pharmacological interventions were effective.

Design:

This was a rapid systematic review with narrative synthesis of evidence, prospectively registered on PROSPERO (ID: CRD42020210892).

Data sources:

We searched MEDLINE, EMBASE, CINAHL via the NICE Evidence Health Databases Advanced Search interface; medRxiv; the Cochrane COVID-19 Study Register; and Google Scholar with no date limits. We included primary studies which documented care of patients dying of COVID-19 under the care of a specialist palliative care team.

Results:

Seven studies, documenting the care of 493 patients met the inclusion criteria. Approximately two thirds of patients required a continuous subcutaneous infusion with median doses of 15 mg morphine and 10 mg midazolam in the last 24 h of life. Four studies described effectiveness by retrospective review of documentation. One study detailed the effectiveness of individual medications.

Conclusions:

A higher proportion of patients required continuous subcutaneous infusion than is typically encountered in palliative care. Doses of medications required to manage symptoms were generally modest. There was no evidence of a standardised yet holistic approach to measure effectiveness of these medications and this needs to be urgently addressed.
Grade Retention and School Dropout: Comparing Specific Grade Levels Across Childhood and Early Adolescence
Authors: Giano Zachary , Williams Amanda L. , Becnel Jennifer N.
Published: May 2021

Students who repeat a grade are at a higher risk of dropping out of high school. Previous research has examined this in a methodologically aggregated way (e.g., repeated any grade versus never repeated) or only specific grades/grade ranges (e.g., Kindergarten or elementary) leaving questions about which grades are more detrimental to repeat with respect to school dropout. This study uses data from the National Center for Education Statistics ( N = 9,309) to comparatively examine which grades, when repeated, show the strongest associations with dropping out. Overall, those who repeated sixth or seventh had the highest odds of dropping out of high school with unique patterns by gender and race/ethnicity. These grades are typically when youth transition into middle school. When examined through a developmental lens, these results highlight the important impact that grade retention while youth experience other normative physical, cognitive, and social changes.
Ivermectin in combination with doxycycline for treating COVID-19 symptoms: a randomized trial
Authors: Mahmud Reaz , Rahman Md. Mujibur , Alam Iftikher , Ahmed Kazi Gias Uddin , Kabir A.K.M. Humayon , Sayeed S.K. Jakaria Been , Rassel Mohammad Aftab , Monayem Farhana Binte , Islam Md Shahidul , Islam Mohammad Monirul , Barshan Anindita Das , Hoque Mohammad Mahfuzul , Mallik MD. Uzzal , Yusuf Mohammad Abdullah , Hossain Mohammad Zaid
Published: May 2021

Objective

We evaluated whether ivermectin combined with doxycycline reduced the clinical recovery time in adults with COVID-19 infection.

Methods

This was a randomized, blinded, placebo-controlled trial in patients with mild-to-moderate COVID-19 symptoms randomly assigned to treatment (n = 200) and placebo (n = 200) groups. The primary outcome was duration from treatment to clinical recovery. Secondary outcomes were disease progression and persistent COVID-19 positivity by RT-PCR.

Results

Among 556 screened patients, 400 were enrolled and 363 completed follow-up. The mean patient age was 40 years, and 59% were men. The median recovery time was 7 (4–10, treatment group) and 9 (5–12, placebo group) days (hazard ratio, 0.73; 95% confidence interval, 0.60–0.90). The number of patients with a ≤7-day recovery was 61% (treatment group) and 44% (placebo groups) (hazard ratio, 0.06; 95% confidence interval, 0.04–0.09). The proportion of patients who remained RT-PCR positive on day 14 and whose disease did not progress was significantly lower in the treatment group than in the placebo group.

Conclusions

Patients with mild-to-moderate COVID-19 infection treated with ivermectin plus doxycycline recovered earlier, were less likely to progress to more serious disease, and were more likely to be COVID-19 negative by RT-PCR on day 14.

Trial Registration

ClinicalTrials.gov Identifier: NCT04523831.

Data Repository ID

Dryad. doi:10.5061/dryad.qjq2bvqf6
Mimics of malignancy caused by concurrent imperforate hymen and transverse vaginal septum: an instructive case and review of the literature
Authors: Wang Ying-Fu , Kuo Shih-Ming , Lin Yu-Chun , Fang Hong-Hsiang , Chu Chun-Hao , Lin Chien-Ming
Published: May 2021

The coexistence of imperforate hymen and vaginal septum is rare and their ability to mimic malignant manifestations have not been frequently reported. This current case report describes a 13-year-old girl that presented with cyclic abdominal pain for 6 months. She was found to have a huge mass via abdominal plain film X-ray and sonography, with inexplicably high levels of serum carcinoembryonic antigen, cancer antigen (CA)-19-9 and CA-125. Pelvic computed tomography imaging disclosed two huge cystic lesions in the uterine and upper vaginal cavities. Surgical intervention conformed the diagnosis of a concurrent imperforate hymen and transverse vaginal septum, echoing the imaging findings of haematocolpometra. Her tumour marker levels gradually returned to normal after surgery. This rare case of concomitant imperforate hymen and transverse vaginal septum highlights that haematocolpometra, a benign disease that might mimic malignancy, should be taken into consideration in any adolescent females with an abdominal mass and amenorrhoea to ensure an early diagnosis and timely appropriate management.
Towards a cultural political economy of the illicit
Authors: Inverardi-Ferri Carlo
Published: May 2021

This article intervenes in debates on the illicit in economic geography, notably in the tensions between cultural and political economic approaches. First, it assesses critiques of political economic evaluations of the illicit. It then offers a ‘trading zone’, drawing upon both cultural and political economy, and argues that the two economic epistemologies are complementary, not mutually exclusive. The article instates political and ecological missing links in cultural political economy to foster multidimensional analyses of illicit practices in discursive, material and ecological registers. It concludes by discussing the broader implications of a cultural political economy of the illicit for economic geography.
Methods to improve wind turbine generator bearing temperature imbalance for onshore wind turbines
Authors: Singh Gopal , Sundaram Kalpathy
Published: May 2021

For better annual energy production, wind turbine generator components are expected to perform efficiently and safely. Development of recent high-efficiency generators and motors leading their designs with less cooling capacity. Bearings are one of the most stressed components in the generator. Recent studies have indicated that bearing failure is the prime cause of generator failure, in wind turbine application. Grease lubrication deterioration was found to be the leading cause of motors and generators bearing failure. Grease service life for generators are closely associated with the operating temperature. One issue with the less cooling design is the higher bearing temperature. This led to marginal lubrication, premature bearing failure, and reduce generator reliability. To verify this and address the issue of inadequate and imbalanced bearing cooling; this paper presents recent experimentation performed on-air to air-cooled squirrel cage induction generator. This test addresses a potential issue with the IC6A1A6 cooled generator design and recommends the updates with corresponding standards. To get optimal bearing life and generator reliability, either allowed bearing operating temperature range should be reduced significantly, by developing a new cooling strategy or standards committee should come up with different intervals of lubrication for both ends of the bearings. Issues similar to with IEEE standard 841 high-efficiency motors can be avoided, where a study performed on the reliability of these motors used in refinery confirmed that motors are at greater risk. A proactive plan based on the result and recommendations in this paper will help to secure the safe wind turbine-generator operation.
Preserving Privacy with Federated Learning in Route Choice Behavior Modeling
Authors: Kweon Yonghyeon , Sun Bingrong , Park B. Brian
Published: May 2021

While big data helps improve decision-making and model developments, it often runs into privacy concerns. An example would be retrieving drivers’ origin and destination information from smartphone navigation apps for developing a route choice behavior model. To conserve privacy, yet to take advantage of big data in navigation applications, the authors propose to apply a federated learning approach, which has shown promising application in predicting smartphone keyboard’s next word without sending text to the server. Additional benefits of using federated learning is to save on data communications, by sending model parameters instead of entire raw data, and to distribute the computational burden to each smartphone instead of to the main server. The results from real-world route navigation usage data from about 30,000 drivers over one year showed that the proposed federated learning approach was able to achieve very similar accuracy to the traditional centralized global model and yet assures privacy.
Network Optimization of Railway Cold Chain Logistics Based on Freight Subsidy
Authors: Lu Yu , Xu Xingfang , Yin Chuanzhong , Zhang Yueyi
Published: May 2021

The proportion of railway cold chain transportation in the overall cold chain logistics transportation market is relatively small in China. Freight subsidies and cold chain train operations are typically effective approaches to guide the public transit of cold chain cargo flow and grow the railway cold chain transportation market. We analyzed the cost structure of a cold chain transportation network. We established a network optimization model of the railway cold chain logistics based on a freight subsidy and designed an adaptive genetic–simulated annealing algorithm (A-SAGA). Taking the cold chain transportation between the Yangtze river delta urban agglomerations and the Chengdu–Chongqing city group as an example, we determined the optimal cold chain logistics transportation scheme using the traditional genetic algorithm and the A-SAGA. Moreover, we conducted sensitivity analysis on freight subsidies, train travel speeds, soft time windows, and carbon tax rates. The results showed that for medium- and long-distance cold chain transportation, the railway market share increased from 17.55% to 18.75% with an increase in the railway freight rate subsidy share from 0% to 30%. More cold chain goods were transported by rail when the soft time window or the carbon tax rate increased. Moreover, the railway market share increased from 17.55% to 43.75% with an increase in the train travel speed from 60 km/h to 120 km/h. Thus, compared with freight subsidy, increasing the train travel speed is a better approach to improve the competitiveness of railway cold chain logistics.
Do We Need a Change in Road Winter Maintenance to Accommodate for Automated Vehicles? A State-of-the-Art Literature Review Considering Automated Vehicle Technology’s Usage of Road Infrastructure During Winter
Authors: Ødegård Ingvild , Klein-Paste Alex
Published: May 2021

For automated vehicles to be allowed to join the modern car fleet, and, in the future, replace human drivers, they must be able to handle adverse weather, including snowy conditions. This literature review focuses on how automated vehicles utilize the road and how this use is suitable for winter maintenance strategies. Where global navigation satellite system (GNSS) service is unavailable, automated vehicles need bare roads to perform relative navigation based on real-time data about lane markings, obstacles, and road infrastructure. Snow-covered tracks hinder vehicle navigation and lane marking detection, which might generate wheel slippage that in turn causes emergency stop and challenging friction estimates. Although the entry of automated vehicles into the car fleet does not demand change in the strategies of winter maintenance, it does demand higher level of service than today. Maintaining an entire road network on which autonomous vehicles always can operate is tremendously expensive and likely not feasible. One solution could be to add another maintenance class in a bare road strategy, that is, an automated vehicle maintenance class with a high level of service and a set of operational criteria allowing automated vehicles to operate. The maintenance class should be used for certain main routes where there is a high frequency of automated vehicles. A model that recommends preferable routes to the destination based on current road conditions within the operational envelope should be provided to the automated vehicle system.
Transit Users’ Mode Choice Behavior During Light Rail Transit Short-Term Planned Service Disruption
Authors: Arslan Asim Muhammad , Weiss Adam , Kattan Lina , Wirasinghe S. C.
Published: May 2021

Planned service disruptions (PSDs) of light rail transit (LRT) improve service reliability, extend infrastructure’s life, and reduce the frequency and impact of unplanned service disruption caused by system failure. However, the literature on the impact of LRT PSDs on transit customers’ travel mode choice behavior is scarce relative to that on unplanned service disruptions. This study aimed to investigate transit customers’ mode choice behavior in response to short-term LRT PSD in the City of Calgary, AB, Canada. A stated preference survey was designed to gather respondents’ mode choices under a set of hypothetical scenarios. A mixed multinomial logit model was estimated using stated preference data. Findings of this study include: (i) stated LRT ridership dropped by about 35% during the examined short-term LRT service disruption; (ii) transit customers who hold a LRT payment pass (monthly, subsidized seniors, low income, and students) and are frequent weekend LRT users are more likely to stay with the LRT mode in case of short-term PSD; (iii) the value of time for transit users during short-term LRT PSD was found to be 11.76 $/h and 13.0 $/h for travel time (excluding wait time) and wait time during travel, respectively. A sensitivity analysis was conducted on key variables to predict choice probabilities of transit alternatives. Recommendations are made to improve Calgary Transit customers’ experience during short-term LRT PSDs.
The effects of propofol on extracorporeal membrane oxygenation oxygenator exchange
Authors: Browder Kelsey L , Ather Ayesha , Pandya Komal A
Published: May 2021

The objective of this study was to determine if propofol administration to veno-venous (VV) extracorporeal membrane oxygenation (ECMO) patients was associated with more incidents of oxygenator failure when compared to patients who did not receive propofol. This was a single center, retrospective cohort study. The primary outcome of the study is oxygenator exchanges per ECMO day in patients who received propofol versus those who did not receive propofol. Patients were 18 years or older on VV-ECMO support between January 1, 2015 and January 31, 2018. Patients were excluded if they required ECMO support for less than 48 h or greater than 21 days. There were five patients in the propofol arm that required oxygenator exchanges and seven patients in the control arm. The total number of oxygenator exchanges per ECMO day was not significantly different between groups ( p = 0.50). When comparing those who required an oxygenator exchange and those who did not, there was no difference in the cumulative dose of propofol received per ECMO hour (0.64 mg/kg/h vs 0.96 mg/kg/h; p = 0.16). Propofol use in patients on VV-ECMO does not appear to increase the number of oxygenator exchanges.
Manipulating Facebook’s Notification System to Provide Evidence of Techno-Social Engineering
Authors: Haenschen Katherine , Frischmann Brett , Ellenbogen Paul
Published: May 2021

Techno-social engineering (TSE) theory argues that digital platforms shape and program human behaviors. We provide empirical evidence of this theory by introducing a novel method to conduct in-network studies on Facebook. We manipulate Facebook’s birthday notification system by recruiting confederates to change their birthday to a randomly assigned date and then measure network members’ responses in terms of whether they leave a greeting or question the veracity of the date. TSE theory leads us to expect that more participants will wish happy birthday on the fake date than question its veracity. We explore variables expected to predict heterogeneity in terms of response: prior birthday wish behavior, friends in common between the confederate and participant, and tie strength. All variables are associated with an increased likelihood of responding to the stimulus; however, none of these variables predict how individuals respond. Even participants who knew the confederate’s birthday and tracked it off-line were still tricked by the stimulus. Results offer empirical evidence supporting TSE theory and provide a new method for studying human–computer interaction.
Transitioning to Long-Term Care: Family Caregiver Experiences of Dementia, Communities, and Counseling
Authors: Zmora Rachel , Statz Tamara L. , Birkeland Robyn W. , McCarron Hayley R. , Finlay Jessica M. , Rosebush Christina E. , Gaugler Joseph E.
Published: May 2021

Objectives: Previous analyses of interventions targeting relationships between family caregivers of people with Alzheimer’s disease and related dementias and residential long-term care (RLTC) staff showed modest associations with caregiver outcomes. This analysis aimed to better understand interpersonal and contextual factors that influence caregiver–staff relationships and identify targets for future interventions to improve these relationships. Methods: Using a parallel convergent mixed methods approach to analyze data from an ongoing counseling intervention trial, descriptive statistics characterized the sample of 85 caregivers and thematic analyses explored their experiences over 4 months. Results: The findings illustrated that communication, perceptions of care, and relationships with staff are valued by family caregivers following the transition of a relative with dementia to RLTC. Discussion: The findings deepen understanding of potential intervention targets and mechanisms. These results can inform future psychosocial and psychoeducational approaches that assist, validate, and empower family caregivers during the transition to RLTC.
Upgrading China through Automation: Manufacturers, Workers and the Techno-Developmental State
Authors: Lei Ya-Wen
Published: May 2021

This article analyses how local states, electronics manufacturers and low-skilled workers perceive and make decisions about automation under China’s techno-developmentalism. Since the early 2010s, local states have made automation – specifically, the substitution of robots for human workers – the linchpin of their techno-developmentalist strategy and set statistical targets to facilitate policy implementation. Although manufacturers realised the limitations of such substitution, most continue to overstate the power of robots in order to receive material and symbolic benefits from local states, which rely on manufacturers to achieve their statistical targets. Meanwhile, most low-skilled workers embrace the state’s vision and see automation as beneficial for national progress, although these workers are the most excluded by state policy. Essentially, China’s techno-developmentalism has led to symbiotic state-capital relations that marginalise low-skilled workers, while reproducing a national sociotechnical imaginary that prioritises abstract notions of technological progress over the actual efficacy of automation, labour protection and social equality.
In-process monitoring in electrical machine manufacturing: A review of state of the art and future directions
Authors: Tiwari Divya , Farnsworth Michael , Zhang Ze , Jewell Geraint W , Tiwari Ashutosh
Published: May 2021

Manual operations feature prominently in the manufacture of many electrical machines. Even though high-volume electrical machine manufacture is dominated by automation, several manufacturing operations continue to involve manual intervention because of the complexity of such operations makes them heavily reliant on high dexterity manual skills and experience. However, quality can be variable due to human involvement. Currently, in order to maintain a high precision of control and required tolerances of the final machine, inspection is performed at various steps during manufacturing and assembly. Detecting a defect at these end-of-line tests can result in significant wasted time and costs due to rework or scrappage. The solution to this problem lies in in-process monitoring particularly for error prone manual operations. This paper presents a literature review of the state-of-the-art available techniques and limitations in process monitoring within the context of electrical machine manufacturing. To quantify the degree of manual activities in process monitoring within electrical machine manufacture, a structured survey of UK based companies was conducted, identifying specific error prone manual processes to target, and gaps in inspection. The survey identified that a significant proportion of activities in electrical machine manufacture are manual, or semi-automated with manual interventions. However, literature review revealed only a limited research in in-process monitoring of manual operations in this area. Finally, two case studies are presented where case study 1 presents a framework for digitisation of a variety of manual manufacturing tasks, and case study 2 demonstrates real-time capture, modelling and analysis of deformable linear objects in electrical machine manufacturing.
Buckling of functionally graded carbon nanotubes reinforced composite joined spherical-cylindrical-spherical thin-walled structure
Authors: Avramov K , Myrzaliyev D , Uspensky B , Sakhno N , Seitkazenova KK
Published: May 2021

Functionally graded carbon nanotubes reinforced composite joined spherical-cylindrical-spherical thin-walled structure under the actions of axial and lateral distributed loads is considered. The static buckling of this structure is analyzed numerically. The Ritz method is used to derive the governing equations of the joined thin-walled structure buckling. Higher-order shear deformation theory is applied to describe the structure stress-strain state. The continuity conditions of the spherical-cylinder junction are derived. The displacements projections are chosen in the special form to satisfy these continuity conditions. The dependences of the buckling axial load on the CNTs distributions, CNTs volume fractions are analyzed numerically.
Adaptive gearshift control of wet dual clutch transmission based on extended state observer and H∞ robust control
Authors: Cheng Kun , Qin DaTong , Jian Junhang , Wu Bangzhi
Published: May 2021

The clutch characteristics of dual clutch transmission (DCT) will change as the service time increases, which will lead to the deterioration of gearshift performance. To reduce the influence of the change in clutch characteristics on the gearshift performance, an adaptive gearshift control method based on the extended state observer and H∞ robust control is proposed. First, the gearshift problem of the DCT is transformed into the reference trajectory tracking problem, and the gearshift reference trajectory is designed using the minimum principle. The uncertain term related to the change in clutch characteristics in the DCT gearshift dynamic model is defined, and an extended state observer is designed to estimate the uncertain term. On this basis, the gearshift controller is designed using the backstepping method, and H∞ robust control is introduced to further improve the adaptation effect of the controller, then the adaptive control laws of the clutch pressure and engine torque are obtained. Finally, the adaptation effect of the proposed method was verified by both simulation and experiment. The results show that the proposed adaptive gearshift control method can effectively avoid the gearshift delay caused by the change in clutch characteristics, and the gearshift jerk in the simulation and experiment is reduced by 55.01% and 34.8%, respectively.
Performance evaluation and entropy generation of chevron-type plate-fin equipped with ribs and holes
Authors: Nejati Barzoki F , Khoshvaght-Aliabadi M , Sheikhzadeh GA , Abbasian Arani AA , Feizabadi A
Published: May 2021

The complexity caused by an enhanced technique may significantly enhance the heat transfer along with a penalty in the pressure drop. Thus, it is needed to assess the counteracting effects between the enhanced heat transfer and the augmented pressure drop in practical applications. In order to comprehensively evaluate the hydrothermal performance of the chevron-type plate-fin (CTPF) equipped with ribs and holes, this study focuses on the relationship between hydraulic and thermal characteristics. Firstly, the relationship between the Colburn factor and the friction factor is presented, then two performance indexes are applied using these factors to evaluate the use of ribs and holes in the CTPIt F is found that the simultaneous use of ribs and holes shows better overall performances as compared with the use of ribs or holes individually. At the same geometrical parameters, the highest values of 1.52 and 1.07 are recorded for these performance indexes. In order to further improve the overall performance of the CTPF, the effects of geometrical parameters are also investigated. With the decrease of corrugation amplitude ( a) and the increase of corrugation length ( l), rib height ( h), and rib thickness ( t), the CTPF performs better overall performances. And, for the models with different levels of hole width ( w), the better performance is seen when this parameter is at the middle level. However, in the studied models, the best overall hydrothermal performance is detected for the model with a = 2.5 mm, l = 60 mm, h = 2.5 mm, t = 10 mm, and w = 10 mm, and highest performance indexes of 2.52 and 1.15 are reported for this model. Likewise, an entropy generation analysis is carried out, and the obtained results are discussed based on the Bejan number and entropy generation number. The results show that the increase of Reynolds number can lead to decrease of Bejan number and to increase of entropy generation number. For Reynolds number ranging from 4000 to 10000, the best model, which is described above, shows 17% decrease in the entropy generation number comparing with the reference model. Finally, two correlations are developed to predict the Bejan number and entropy generation number of the current study.
Non-linear radiation effect on dusty fluid flow near a rotating blunt-nosed body
Authors: Rafiq M , Siddiqa Sadia , Begum Naheed , Al-Mdallal Q , Hossain MA , Gorla Rama Subba Reddy
Published: May 2021

A two-phase, dusty boundary-layer flow over an isothermally heated rotating hemisphere is studied for the laminar, incompressible fluid. The contribution of non-linear thermal radiation is analyzed by using the Rosseland diffusion approximation model. The difficulty of having a unified mathematical treatment of the above problem is due to the complex nature of the governing partial differential equations, which arises from the transverse curvature of the round-nosed body, buoyant force, and thermal radiation. Therefore, this study presents a theoretical analysis of a dusty flow and heat transfer over a rotating axisymmetric round-nosed body (for example, hemisphere). In industries, for instance, vehicle industry, blunt-nosed shapes (or round-nosed body) are preferred because it provides better thermal management. The governing equations, along with their appropriate boundary conditions, are numerically solved using the iterative, implicit finite difference method. Numerical solutions are illustrated in the form of streamwise velocity distribution, spanwise velocity distribution, temperature distribution, and skin friction and heat transfer coefficients. The numerical scheme is validated through comparison with the benchmark solutions available in the literature. Solutions obtained here are discussed for i) pure and dusty air and ii) pure and dusty water. A wide range of thermal radiation parameter is tested for the above two cases, and it is found that skin friction coefficient achieves asymptotic behavior for [Formula: see text]; however, heat transfer coefficient increases considerably as much as we strengthen the parameter Rd. Further, momentum and thermal boundary layer thicknesses also increase for [Formula: see text]. Computations are also performed for the buoyancy parameter, λ, ranging from 0 to [Formula: see text], which respectively covers the solution of pure forced convection ( λ = 0) and pure natural convection ([Formula: see text]) boundary layer on a rotating hemisphere.
Natural convection inside a heat source embedded wavy porous cavity containing an insulated obstacle
Authors: Barman Prabir , Rao PS
Published: May 2021

In this finite element analysis of natural convection, cooling of a heat source embedded with a wavy porous cavity containing an insulated obstacle is investigated. A heat source is submitted to the left vertical wall, and the wavy right vertical wall is kept at fixed low temperature keeping top and bottom walls as insulated. The insulated obstacle which is placed inside the cavity is either square or circular in shape. The non-dimensional governing equations are solved by Galerkin finite element method and the results are presented in terms of streamlines and isotherms. The parameters considered for the investigation are Rayleigh-Darcy number ([Formula: see text]), amplitude of the wavy wall [Formula: see text], undulation of wavy wall per unit length ( N = 3) and shape of the obstacle. From the obtained results, mathematical correlations to calculate the maximum temperature of the heater and average Nusselt number with governing parameters are presented, and it is observed that the presence of a square insulated body reduces the convection process over a circular body; also, for a fixed Ra, the effect of obstacle at a particular portion of the cavity falls off with increment in a.