bluuebunny/crossref_metadata_2025 huggingface dataset:
Slicing strategy and process of laser direct metal deposition (DMD) of the inclined thin-walled part under open-loop control
Authors: Chen Liaoyuan , Yu Tianbiao , Chen Ying , Wang Wanshan
Published: November 2021

Purpose

The purpose of this paper is to improve the dimensional accuracy of inclined thin-walled parts fabricated by laser direct metal deposition (DMD) under an open-loop control system.

Design/methodology/approach

In this study, a novel method of the adaptive slicing method and DMD process with feedback adjustment of deposition height has been developed to successively fabricate complex inclined thin-walled square tube elbow parts. The defocus amount was used as a variable to the matching between the deposition thickness and the adaptive slicing height.

Findings

The low relative error of dimensional accuracy between experimental and designed parts shows that the matching of the single-layer deposition thickness and the adaptive slicing height can be realized by optimizing the defocusing amount. The negative feedback of the thin-wall part height can be achieved when the defocus amount and the z-axis increment are less than deposition thickness. The improvement of dimensional accuracy of inclined thin-walled parts is also attributed to the optimized scanning strategy.

Practical implications

The slicing method and deposition process can provide technical guidance for other additive manufacturing (AM) systems to fabricate metal thin-walled parts with high dimensional accuracy because the feedback control of deposition height can be realized only by the optimized process.

Originality/value

This study provides a novel adaptive slice method and corresponding the deposition process, and expands the slicing method of AM metal parts.
Comparing two seized drug workflows for the analysis of synthetic cannabinoids, cathinones, and opioids
Authors: Sisco Edward , Burns Amber , Schneider Elizabeth , Miller Charles R. , Bobka Laurel
Published: November 2021

As the challenges faced by drug chemists persist, due to the presence of emerging drugs, laboratories continue to look for new solutions, ranging from existing methods to implementation of entirely new technology. A common barrier for making workflow changes is a lack of pre‐existing data demonstrating the potential impact of these changes. In this study, we compare, qualitatively and quantitatively, an existing workflow for seized drug analysis to an experimental workflow. Four chemists were asked to analyze a total of 50 mock case samples across the two workflows. The existing workflow employed color tests for screening alongside general purpose GC‐FID and GC‐MS analyses for confirmation. The experimental workflow combined DART‐MS screening with class‐specific (targeted) GC‐MS analysis for confirmation. Comparison of the workflows showed that screening by DART‐MS required the same amount of time as color tests but yielded more accurate and specific information. Confirmation using the existing workflow required more than twice the amount of instrument time and data interpretation time while also presenting other analytical challenges that prevented compound confirmation in select samples. Targeted GC‐MS methods simplified data interpretation, reduced consumption of reference materials, and addressed almost all limitations of general‐purpose methods. While the experimental workflow requires modifications and answering of additional research questions, this study shows how rethinking analytical workflows for seized drug analysis could reduce turnaround times, backlogs, and standards consumption. It also demonstrates the potential impact of being able to investigate workflow changes prior to implementation.
Serratia marcescens‐S3 inhibits Potato virus Y by activating ubiquitination of molecular chaperone proteins NbHsc70‐2 in Nicotiana benthamiana
Authors: Ge Ming , Gong Mingyue , Jiao Yubing , Li Ying , Shen Lili , Li Bin , Wang Yujie , Wang Fenglong , Zhang Songbai , Yang Jinguang
Published: November 2021

The potato virus Y (PVY) is a plant virus that causes massive crop losses globally, especially in Solanaceae crops. A strain of the plant growth‐promoting rhizobacterium (PGPR), Serratia marcescens‐S3 was found to inhibit PVY replication in Nicotiana benthamiana. However, there have been no in‐depth studies demonstrating the underlying mechanism. In the current study, we found that ubiquitination of NbHsc70‐2 is an important way for Serratia marcescens‐S3 to trigger induced systemic resistance (ISR). After the treatment with S. marcescens‐S3, the protein level of NbHsc70‐2 reduced significantly. Inhibiting of ubiquitination increased the accumulation of NbHsc70‐2 in plants and reduced S. marcescens‐S3‐mediated resistance to PVY. Furthermore, transgenic engineered Nicotiana benthamiana NbHsc70‐2KO and NbHsc70‐2USM were constructed using CRISPR‐Cas9‐mediated NbHsc70‐2 knock‐out and ubiquitination respectively. S. marcescens‐S3 significantly reduced the inhibition of NbHsc70‐2 protein accumulation in NbHsc70‐2KO and NbHsc70‐2USM. The virulence of PVY was stronger in NbHsc70‐2USM than the wild‐type plants. These results showed that S. marcescens‐S3 increases the ubiquitination of NbHsc70‐2 to inhibit the recruitment of molecular chaperone NbHsc70‐2 to reduce its replication and infection of PVY.
Indosinian Supergene Karsts in the Qaidam Basin, NW China: Evidence from Paleo‐tectonics, Paleoclimates and Paleo‐fluids
Authors: LI Zongxing , PENG Bo , QI Kening , LIU Dapeng , MA Yinsheng , ZHANG Wang , HU Junjie , WANG Jiaqi
Published: November 2021

In the Qaidam basin, Northwest China, karstic fissures and caves are developed in many places of the Lower Carboniferous Chengqianggou Fm. and Huaitoutala Fm. and the Upper Carboniferous Keluke Fm., in which are found typical karstic marks. Several suites of transgressive carbonate rocks formed during the Late Paleozoic epoch are preserved as reservoir properties in the Qaidam basin, with paleokarst‐related cave‐fractured diagenetic structures, which provided the basis for cave‐fractured development. Carbonate and clastic samples covering or infilling caves and fractures in Carboniferous strata were collected in the eastern Qaidam basin to focus on petrological and geochemical analyses of karst and infilling materials. Based on this study of the Caledonian diagenetic sequence, and bitumen‐infilled inclusion temperature and burial history, there existed a continuous atmospheric freshwater leaching process, which played a critical role in the construction of the Carboniferous supergene paleokarsts. Investigation and survey of the tectonic setting, plate paleolatitude and river development intensity also proves that there was abundant rainfall during the Indosinian period, after which the strata undergo a shallow burial process. Because Indosinian period is earlier than the key timing of hydrocarbon‐generation of the Carboniferous source rocks, this kind of karst reservoir has potential significance for oil‐gas resources in this area.
Knowledge of end‐of‐life law: A cross‐sectional survey of general practitioners working in aged care
Authors: Sellars Marcus , White Ben , Yates Patsy , Willmott Lindy
Published: November 2021

Objective

To describe the knowledge of end‐of‐life law and experiences in practice at the end of life amongst Australian general practitioners (GPs).

Methods

A cross‐sectional online survey of GPs practising in aged care settings in Queensland (QLD), New South Wales (NSW) and Victoria (VIC).

Results

From 521 potential GPs, 160 (response rate 30.7%) were included in the final sample. Most participants (62%) reported experience with six key end‐of‐life areas at least ‘a few times’, including 74% administering medication for pain and symptom relief, and 67% facilitating advance care planning ‘several’ or ‘many times’ and perceiving they had ‘some’ knowledge of end‐of‐life law (53%, n = 84). However, low‐to‐moderate actual levels of end‐of‐life legal knowledge were identified (mean correct response of 5.24 out of 9).

Conclusions

Australian GPs working in aged care may have low‐to‐moderate knowledge about end‐of‐life law despite frequently making end‐of‐life decisions in clinical practice.
A randomised controlled provider‐blinded trial of community health workers in sickle cell anaemia: effects on haematologic variables and hydroxyurea adherence
Authors: Smith Wally R. , McClish Donna K. , Lottenberg Richard , Sisler India Y. , Sop Daniel , Johnson Shirley , Villella Anthony , Liles Darla , Yang Elizabeth , Chen Ian
Published: November 2021

Hydroxyurea (hydroxycarbamide) (HU) for sickle cell anaemia (SCA) is underutilised. Case management is an evidence‐based health management strategy and in this regard patient navigators (PNs) may provide case management for SCA. We hypothesised that HU‐eligible patients exposed to PNs would have improved indicators of starting HU and HU adherence. We randomised 224 HU‐eligible SCA adults into the Start Healing in Patients with Hydroxyurea (SHIP‐HU) Trial. All patients received care from trained physicians using standardised HU prescribing protocols. Patients in the Experimental arm received case management and education from PNs through multiple contacts. All other patients were regarded as the Control arm and received specialty care alone. Study physicians were blinded to the study arms and did not interact with PNs. At baseline, 6 and 12 months we assessed and compared laboratory parameters and HU adherence indicators. Experimental patients had higher 6‐month mean fetal haemoglobin (HbF) levels than controls. But at 12 months, mean HbF was similar, as were white blood cell count, absolute neutrophil count, total haemoglobin, platelet count and mean corpuscular volume. At 12 months there were fewer experimental patients missing HU doses than controls (mean 1·8 vs. 4·5, P = 0·0098), and more recent HU prescriptions filled than for controls (mean 53·8 vs. 92 days, median 27·5 vs. 62 days, P = 0·0082). Mean HU doses were largely similar. We detected behavioural improvements in HU adherence but no haematological improvements by adding PNs to specialty care.
1H‐1,2,3‐triazole embedded Isatin‐Benzaldehyde‐bis(heteronuclearhydrazones): design, synthesis, antimycobacterial, and cytotoxic evaluation
Authors: Sharma Bharvi , Kumar Sumit , Preeti  , Johansen Matt D. , Kremer Laurent , Kumar Vipan
Published: November 2021

Rapid growth of global drug‐resistant tuberculosis and urgent requirement for short treatment regimens is stimulating the need for discovery of new TB drugs. In this work, we report the design, synthesis and in vitro antimycobacterial evaluation of a library of isatin‐derived bis(heteronuclear hydrazones). Evaluation results revealed that the inclusion of isoniazid core into 1H‐1,2,3‐triazole tethered isatin‐benzaldehydes improved the antimycobacterial activity on tuberculosis mc26230 strain and significantly reduced the cytotoxicity against Vero cells. However, the introduction of semicarbazones/thiosemicarbazones or pyrazine‐2‐carbohydrazide produced the opposite effects. The compounds with isoniazid and polar‐donating groups at the C‐5 position of isatin emerged as the most promising conjugates with MIC99 = 0.36 µg/ml. The most active compounds were non‐cytotoxic to Vero cells (IC50>100 µg/ml) with selectivity indices >277.
Validity and reliability of the Family Empowerment Scale for parents of children with cleft lip and/or palate
Authors: Boztepe Handan , Çınar Sevil , Kanbay Yalçın , Acımış Burcu , Özgür Figen , Terzioglu Füsun
Published: November 2021

Background

Empowerment is recognized as a crucial concept in strengthening the position of parents in healthcare services. This study aimed to evaluate the validity and reliability of the Turkish Family Empowerment Scale (FES).

Methods

This methodological study was conducted between January and March 2021, with 348 family members actively caring for their children in the age group of 0–18 years with cleft lip and/or palate (CL/P). The English FES was translated into Turkish using back translation and modified so that it is generic and convenient for all families. The construct validity, internal validity, internal consistency, and split‐half test reliability and responsiveness of the Turkish FES were examined.

Results

The original FES structure with three factors (family, health services provided to the child and community participation) and 34 items was verified in Turkish culture. This obtained structure can explain 66% of the variance of the relevant concept. Scores of parents ranged between 34 and 170 points. Increasing scores indicated a positive significance regarding family empowerment. The Cronbach's α reliability coefficient of the scale was calculated as 0.976.

Conclusion

The study findings and the goodness‐of‐fit values indicated that the FES and its Turkish version are a valid and reliable measurement instrument to be used in Turkish culture.
Adult coloration of the Bearded Vulture (Gypaetus barbatus) in the Pyrenees: relation to sex, mating system and productivity
Authors: Duchateau Stéphane , Chéliz Gonzalo , Gil Juan Antonio , López‐López Pascual
Published: November 2021

Cosmetic coloration is not a common phenomenon among bird species. Adult Bearded VulturesGypaetus barbatustypically show orange coloration in head, chest, belly and tarsus feathers that is the result of mud baths in ferruginous substrates. Several non‐mutually exclusive visual signalling hypotheses can be proposed to explain this phenomenon. Coloration could be used to signal: (1) dominance towards conspecifics, with darker birds being dominant (status signalling hypothesis); (2) sex (gender signalling hypothesis) because females are usually more intensely coloured; (3) individual quality for mate choice (quality signalling hypothesis); or (4) different reproductive strategies between individuals (e.g. in polyandrous trios). Here we report results from systematic monitoring of breeding Bearded Vultures in the pre‐laying period in the central and western Pyrenees (Spain and France) between 2016 and 2020, including 162 individuals from 70 reproductive units (48 pairs and 22 trios). We classified individuals as being white, pale, medium or dark, and analysed the relationship with sex, mating system (pair or trios) and average productivity across years. Our results showed that the most common form was medium (67%), then pale (22%), dark (9%) and white (2%) morphs. Overall, females were darker than males, but with a large overlap in coloration. In trios, dominant males were darker than subordinate males, although differences were not statistically significant. The mating system (pair or trio) did not influence female coloration. A multimodel comparison showed that the number of years of territory occupation, mating system and their combination (but not coloration) were the best predictors of average productivity. Our results do not support the gender signalling hypothesis. The reproductive strategy signalling hypothesis might be supported because beta males were, on average, paler than males in pairs, but this topic requires further investigations because our results were inconclusive. Finally, that females (thought to be dominant because of their slightly larger size) were on average darker than males agrees with the status signalling hypothesis, although an experimental approach would be needed to formally test this hypothesis.
A level playing field for migrant entrepreneurs? The legal and policy landscape across EU and OECD countries
Authors: Solano Giacomo
Published: November 2021

Migrant entrepreneurship has been recognized as a form of integration in the country of destination and a viable alternative of decent and sustainable employment for migrants. Laws and policies can create barriers or support migrants who start a business in the country of destination. Despite their importance, these laws and policies have received scant attention from academic scholarship. By applying the mixed embedded approach, this article analyses the institutional and policy framework for migrant entrepreneurs in European Union (EU) and Organisation for Economic Cooperation and Development (OECD) countries, and how this framework varies according to the migrants’ individual legal status and gender. In order to do so, this article draws upon the findings of two different studies conducted on the topic. The first one analyses the national institutional framework for migrant entrepreneurs of these countries. The second study consists of a review of measures to foster migrant entrepreneurship in the same sample of countries. On the one hand, this article shows that the institutional framework restricts access to self‐employment for some categories of migrants (e.g. based on their legal status). On the other hand, a wide range of measures are now available to support migrant entrepreneurs. However, these measures treat them as a rather homogeneous group. These findings suggest that the fact that some migrants are less engaged in self‐employment or face more difficulties may be explained by the lack of institutional opportunities and policy support.
Identifying dementia in Down syndrome with the Severe Impairment Battery, Brief Praxis Test and Dementia Scale for People with Learning Disabilities
Authors: Wallace E. R. , Harp J. P. , Van Pelt K. L. , Koehl L. M. , Caban‐Holt A. M. , Anderson‐Mooney A. J. , Jicha G. A. , Lightner D. D. , Robertson W. C. , Head E. , Schmitt F. A.
Published: November 2021

Background

Individuals with Down syndrome (DS) are at high risk for dementia, specifically Alzheimer's disease. However, many measures regularly used for the detection of dementia in the general population are not suitable for individuals with DS due in part to floor effects. Some measures, including the Severe Impairment Battery (SIB), Brief Praxis Test (BPT) and Dementia Scale for People with Learning Disabilities (DLD), have been used in clinical trials and other research with this population. Validity research is limited, particularly regarding the use of such tools for detection of prodromal dementia in the DS population. The current project presents baseline cross‐sectional SIB, BPT and DLD performance in order to characterise their predictive utility in discriminating normal cognition, possible dementia and probable dementia in adult DS.

Method

Baseline SIB, BPT and DLD performances from 100 individuals (no dementia = 68, possible dementia = 16 & probable dementia = 16) were examined from a longitudinal cohort of aging individuals with DS. Receiver operating characteristic curves investigated the accuracy of these measures in relation to consensus dementia diagnoses, diagnoses which demonstrated high percent agreement with the examining neurologist's independent diagnostic impression.

Results

The SIB and BPT exhibited fair discrimination ability for differentiating no/possible versus probable dementia [area under the curve (AUC) = 0.61 and 0.66, respectively]. The DLD exhibited good discrimination ability for differentiating no versus possible/probable dementia (AUC = 0.75) and further demonstrated better performance of the DLD Cognitive subscale compared with the DLD Social subscale (AUC = 0.77 and 0.67, respectively).

Conclusions

Results suggest that the SIB, BPT and DLD are able to reasonably discriminate consensus dementia diagnoses in individuals with DS, supporting their continued use in the clinical assessment of dementia in DS. The general performance of these measures suggests that further work in the area of test development is needed to improve on the AUCs for dementia status discrimination in this unique population. At present, however, the current findings suggest that the DLD may be the best option for reliable identification of prodromal dementia in this population, reinforcing the importance of including informant behaviour ratings in assessment of cognition for adults with DS.
Incidence of chest X‐ray abnormalities early in the third trimester of twin pregnancy and its relationship with the subsequent development of preeclampsia
Authors: Yagi Kazunobu , Kawaguchi Haruna , Yamamoto Ryo , Hayashi Shusaku , Ishii Keisuke
Published: November 2021

Aim

To clarify the incidence of abnormal findings on chest X‐ray (CXR) early in the third trimester of twin pregnancy and its relationship with the development of preeclampsia and preeclampsia‐related diseases.

Methods

This was a retrospective cohort study conducted among women with twin pregnancies who underwent chest radiography for preoperative screening early in the third trimester and delivered at our center at >34 weeks' gestation from 2013 to 2017. The primary outcome was the incidence of positive CXR findings, defined either as cardiomegaly or blunting of the costophrenic angle. The secondary outcome was the incidence of maternal complications, including preeclampsia; hemolytic, elevated liver enzymes, and low platelet syndrome; eclampsia; cerebrovascular disease; and placental abruption. We evaluated the significance of positive CXR findings, in addition to confounding factors, in the subsequent development of preeclampsia.

Results

During the study period, 358 twin pregnancies were identified, and 330 were finally enrolled. The incidence of positive CXR findings was 18.2%. The incidence of preeclampsia in the CXR‐positive group was 36.7% (22/60), which was significantly higher than that in the CXR‐negative group (7.0% [19/270]) (p < 0.01). Moreover, positive CXR findings were independently associated with subsequent preeclampsia (adjusted odds ratio: 9.15, 95% confidence interval: 4.13–20.3).

Conclusion

In twin pregnancies, the incidence of CXR abnormalities early in the third trimester was 18.2%, even without the development of hypertension. This should be considered a significant risk factor for subsequent preeclampsia.
Morph‐specific investment in testes mass in a trimorphic beetle, Proagoderus watanabei
Authors: Parrett J. M. , Slade E. M. , Knell R. J.
Published: November 2021

When competition between males for mates is intense, it is common to find that some males will adopt alternative tactics for acquiring fertilizations, often involving the use of ‘sneak’ tactics whereby males avoid precopulatory contests. These alternative tactics are sometimes associated with discrete differences in male morphology, with sneak males investing less in weaponry but more in traits such as testes which may give an advantage in sperm competition. In some cases, it appears that males develop into more than two morphs, with a number of examples of tri‐ and even tetramorphic arthropod species being described. Here, we analyse the scaling relations of the dung beetle species Proagoderus watanabei, which expresses two distinct weapon traits: paired head horns and a pronotal horn. We find that males of this species are trimorphic, with alpha males expressing long head horns and a pronotal horn, beta males with long head horns but no pronotal horn and gamma males with short head horns only. We also find that alpha males invest relatively less in testes than do beta or gamma males, indicating that beta and gamma males in this species probably experience higher risks of sperm competition than do alphas.
Prevalence of Candida species in Psoriasis
Authors: Elsner Kevin , Holstein Julia , Hilke Franz Joachim , Blumenstock Gunnar , Walker Birgit , Schmidt Sybille , Schaller Martin , Ghoreschi Kamran , Meier Katharina
Published: November 2021

Background

Psoriasis patients are more frequently colonised with Candida species. The correlation between fungal colonisation and clinical severity is unclear, but may exacerbate psoriasis and the impact of antipsoriatic therapies on the prevalence of Candida is unknown.

Objectives

To examine the prevalence of C species in psoriasis patients compared to an age‐ and sex‐matched control population, we investigated the influence of Candida colonisation on disease severity, immune cell activation and the interplay on psoriatic treatments.

Methods

The prevalence of C species was examined in 265 psoriasis patients and 200 control subjects by swabs and stool samples for fungal cultures. Peripheral mononuclear blood cells (PBMCs) were collected from 20 fungal colonised and 24 uncolonised patients and stimulated. The expression of interferon (IFN)‐γ, IL‐17A, IL‐22 and tumour necrosis factor (TNF)‐α from stimulated PBMCs was measured by quantitative real‐time polymerase chain reaction (qPCR).

Results

A significantly higher prevalence for Candida was detected in psoriatic patients (p ≤ .001) compared to the control subjects; most abundant in stool samples, showing Candida albicans. Older participants (≥51 years) were more frequent colonised, and no correlation with gender, disease severity or systemic treatments like IL‐17 inhibitors was found.

Conclusions

Although Candida colonisation is significantly more common in patients with psoriasis, it does not influence the psoriatic disease or cytokine response. Our study showed that Candida colonisation is particularly more frequent in patients with psoriasis ≥51 years of age. Therefore, especially this group should be screened for symptoms of candidiasis during treatment with IL‐17 inhibitors.
Morphological and phylogenetic characterization of fungi within Hymenochaetales: introducing two new species from southern China
Authors: Luo Xi , Chen Yu‐Hui , Zhao Chang‐Lin
Published: November 2021

Two new wood‐inhabiting fungal species, Lyomyces niveus and L. ochraceoalbus spp. nov. are proposed based on a combination of morphological and molecular evidence. Lyomyces ochraceoalbus is characterised by resupinate basidiomata with tuberculate, cracking hymenial surface, clavate basidia with a median constriction, gathering numerous irregular crystals, and thin‐walled basidiospores with one or two globules. Lyomyces niveus is characterised by resupinate basidiomata, smooth to grandinioid hymenial surface, presence of three kinds of cystidia, and broadly ellipsoid basidiospores. Sequences of the ITS and nLSU gene regions were generated, and phylogenetic analyses were performed with maximum likelihood, maximum parsimony and Bayesian inference methods. The phylogenetic reconstruction of Schizoporaceae based on a concatenated ITS+nLSU dataset showed that the two new species are nested in Lyomyces. A second phylogenetic analysis, of the genus Lyomyces, demonstrated that multiple isolates of L. niveus forms a monophyletic lineage which is sister to a clade comprising L. crustosus, L. juniperi, L. ochraceoalbus and L. vietnamensis. Moreover, L. ochraceoalbus is closely related to L. crustosus.
Modulating eating behavior with transcranial direct current stimulation (tDCS): A systematic literature review on the impact of eating behavior traits
Authors: Beaumont Jordan D. , Smith Natalie C. , Starr David , Davis Danielle , Dalton Michelle , Nowicky Alexander , Russell Mark , Barwood Martin J.
Published: November 2021

Transcranial direct current stimulation (tDCS) is becoming an increasingly popular technique for altering eating behaviors. Recent research suggests a possible eating behavior trait‐dependent effect of tDCS. However, studies recruit participant populations with heterogeneous trait characteristics, including “healthy” individuals who do not present with eating behavior traits suggesting susceptibility to overconsumption. The present review considers the effects of tDCS across eating‐related measures and explores whether a trait‐dependent effect is evident across the literature. A literature search identified 28 articles using sham‐controlled tDCS to modify eating‐related measures. Random effects meta‐analyses were performed, with subgroup analyses to identify differences between “healthy” and trait groups. Trivial overall effects (g = −0.12 to 0.09) of active versus sham tDCS were found. Subgroup analyses showed a more consistent effect for trait groups, with small and moderate effect size (g = −1.03 to 0.60), suggesting tDCS is dependent on participants' eating behavior traits. Larger effect sizes were found for those displaying traits associated with study outcomes (e.g., heightened food cravings). “Healthy” individuals appear to be unresponsive to stimulation. Based on this meta data, future work should recruit those with eating behavior trait susceptibilities to overconsumption, focusing on those who present with traits associated with the outcome of interest.
Detection of the HLA‐B*15:360 allele in a Taiwanese bone marrow donor
Authors: Yang Kuo‐Liang , Li Chi‐Cheng , Lin Py‐Yu
Published: November 2021

Four nucleotide substitutions in exon 3 of HLA‐B*15:01:01:01 result in a novel allele, HLA‐B*15:360.
Technical and Economic Evaluation on the Integrated Heating System With Coupled Heat Pump and Backpressure Turbine
Authors: Wei Shuzhou , Wang Jinxing , Song Haiwen , Zhou Xing
Published: November 2021

The increasing depletion of fossil energy and the gradual aggravation of environmental pollution have increased the necessity of renewable energy applications. However, the intermittent characteristics of renewable energy power generation need to increase the flexibility of the original coal-fired power unit for balancing the supply and demand of the power system. In this work, two 350 MWe condensing units (CUs) were taken as examples and the thermodynamic simulation models were built by the ebsilon software to evaluate their technical and economic characteristics. At the same time, the system is coupled with heat pump (HP) and backpressure turbine (BT) for heating. Among them, the rated steam intake of HP is 194.9 t/h, and the rated steam intake of BT is 214.5 t/h. Results show that under the same requirements, the energy consumption with the backpressure turbine priority principle (BTtlp principle) is smaller than that with the heat pump priority principle (HPtlp principle). However, under the same thermal load conditions, the electrical load with the HPtlp principle can drop lower than that with the BTtlp principle. Meanwhile, there is an optimization interval for the output distribution of HP and BT. From the energy current diagram, it can be found that under the design main steam and given thermal load condition, the power generation efficiency of coupled mode is 0.74% more than that of HP mode and is 1.93% more than that of direct mode, while under the given thermal and electrical load condition, the system’s boiler output with direct mode is 3.37% more than that with HP mode and is 5.34% more than that with coupled mode. This provides a theoretical basis for the subsequent comprehensive evaluation of heating reformation.
Combined Experimental/Finite Element Investigation of Transverse Barrel Movement
Authors: Leonhardt David , Garnich Mark
Published: November 2021

Transverse barrel movement was measured during the firing of a Ruger Precision Rifle chambered in 6.5 Creedmoor. The use of laser vibrometers enabled high-speed measurement at good resolution during the projectile in-bore transient. Lateral vibrations have been broken into constituents based on source using a combination of experiments and finite element modeling. Individual contributors to overall vibration discussed include firing pin impact, primer ignition, and the combined load of combustion gas pressure and projectile–bore interaction. Good correlation was obtained between barrel motion in the vertical plane and model predictions during the in-bore period. It was concluded that action of the firing pin and primer impulse contribute significantly to the overall dynamic response of the barrel.
A Geometric Approach for Error Space Estimation of Planar Linkage
Authors: Ding Jianzhong , Wang Chunjie
Published: November 2021

This article develops a geometric method to estimate the clearances-induced error space of any planar linkage. The error space discussed here represents the unconstrained mobility of the end-effector when actuators of the mechanism are locked, and is expressed by a connected geometry in 3-dimensional Euclidean frame {x, y, θ}. First, error space of the planar mechanism is modeled and closed-form expressions are derived. Then, levels of joints in error propagation analysis are defined and illustrated with an example of a eight-bar linkage, following which error propagation path among closed-loop structures is given. The modeling of error propagation and accumulation is introduced in detail. Moreover, a simplification technique is discussed for simple expression of the error space propagated from previous joints. This study provides a way to have a deep insight into the accuracy performance of any planar linkage and the proposed error space evaluation method is validated by case study of error space estimation of a four-bar linkage and a six-bar linkage. For the four-bar linkage, the structure with optimal accuracy is obtained. And for the six-bar linkage, the error space of the end-effector is expressed in closed form and visualized in the 3-dimensional frame. Finally, this work is concluded and advances of the proposed method are emphasized.
A Novel Approach With Bayesian Networks to Multi-Robot Task Allocation in Dynamic Environments
Authors: Chuang Ching-Wei , Cheng Harry H.
Published: November 2021

In the modern world, building an autonomous multi-robot system is essential to coordinate and control robots to help humans because using several low-cost robots becomes more robust and efficient than using one expensive, powerful robot to execute tasks to achieve the overall goal of a mission. One research area, multi-robot task allocation (MRTA), becomes substantial in a multi-robot system. Assigning suitable tasks to suitable robots is crucial in coordination, which may directly influence the result of a mission. In the past few decades, although numerous researchers have addressed various algorithms or approaches to solve MRTA problems in different multi-robot systems, it is still difficult to overcome certain challenges, such as dynamic environments, changeable task information, miscellaneous robot abilities, the dynamic condition of a robot, or uncertainties from sensors or actuators. In this paper, we propose a novel approach to handle MRTA problems with Bayesian Networks (BNs) under these challenging circumstances. Our experiments exhibit that the proposed approach may effectively solve real problems in a search-and-rescue mission in centralized, decentralized, and distributed multi-robot systems with real, low-cost robots in dynamic environments. In the future, we will demonstrate that our approach is trainable and can be utilized in a large-scale, complicated environment. Researchers might be able to apply our approach to other applications to explore its extensibility.
A Review of Design-Related Literature Concerning Cognitive Processes, Prototyping Strategies, and Modeling Processes
Authors: Murphy Alexander R. , Watson Bryan C. , Tomko Megan E. , Hilton Ethan C. , Linsey Julie S.
Published: November 2021

In industry and academia, designers and engineers use prototyping at various stages in the design process to evaluate progress, archive process, assess viability, and communicate mental models to a team. Cognitive processes not only play a huge role during the design process, but also have causal relationships with various prototyping strategies. However, these causal relationships are not well understood in the design field. This paper presents a review of design-field literature related to cognitive processes, prototyping strategies, and modeling processes to identify literature consensus, consolidate experimental results, and expose gaps in the literature. After analysis of the literature, Fixation, Team Cognition, Iterative Prototyping, and Rapid Prototyping are the most well researched areas, especially when compared to their effects on cognitive processes. Sunk Cost, Requirement Relaxation, and Expertise are areas that could be better understood. The relationships between relevant cognitive processes, prototyping strategies, and modeling processes are consolidated into a data visualization that invites researchers and novices alike to explore the field of design in a fresh way that could spark new research endeavors or provoke interest in the field. This literature review and analysis reveals trends in design research through a novel approach with an emphasis on cognition, as well as provides a consolidated cannon of work that gives a sense of what has already been done on these topics and what is still left to explore.
Approximate Real-Time Force Spectroscopy Within Amplitude-Modulation Atomic Force Microscopy Topographical Imaging Using Few Harmonics and Fourier Methods
Authors: Uluutku Berkin , Solares Santiago D.
Published: November 2021

Quantitative measurement of the probe-sample interaction forces as a function of distance and time during imaging has been at the forefront of atomic force microscopy (AFM) research. This type of information is extremely valuable for understanding the material response to a variety of stimuli and interactions, such as mechanical deformations that vary in magnitude and rate of application, chemical interactions, or electromagnetic interactions. A variety of methods for performing such measurements simultaneously with topographical imaging is available, including methods based on Fourier analysis. Within these methods, reconstruction of the tip-sample force curve generally requires measurement of a large number of harmonics of the probe oscillation, which presents challenges such as the need for specialized hardware, low signal-to-noise ratio, and the need for extensive user expertise. In this paper, we present a simple method to perform a Gaussian-model-based fit of the tip-sample force curve across the surface, simultaneously with imaging, which requires measurement of only the first two or three harmonics for elastic materials. While such an approach only offers an approximate representation of the force curve, it can be highly accurate and fast, and has low instrumentation requirements, such that it can be relatively simple to implement on most commercial AFM setups.
Local Trajectory Planning for Autonomous Racing Vehicles Based on the Rapidly-Exploring Random Tree Algorithm
Authors: Tramacere Eugenio , Luciani Sara , Feraco Stefano , Circosta Salvatore , Khan Irfan , Bonfitto Angelo , Amati Nicola
Published: November 2021

This paper presents a local trajectory planning method based on the Rapidly-exploring Random Tree (RRT) algorithm using Dubins curves for autonomous racing vehicles. The purpose of the investigated method is the real-time computation of a trajectory that could be feasible in autonomous driving. The vehicle is considered as a three Degree-of-Freedom bicycle model and a Model Predictive Control (MPC) algorithm is implemented to control the lateral and longitudinal vehicle dynamics. The trajectory planning algorithm exploits a perception pipeline using a LiDAR sensor that is mounted onto the front wing of the racing vehicle. The MPC computes the acceleration/ deceleration command and the front wheel steering angle to follow the predicted trajectory. The trajectory and control algorithms are tested on real data acquisition performed on-board the vehicle. For validation purposes, the vehicle is driven autonomously during different maneuvers performed in the racing environment that is structured with traffic cones. The feasibility of the algorithm is evaluated in terms of error with respect to the planned trajectory, tracking velocity and maximum longitudinal acceleration. The effectiveness of the method is also evaluated with respect to command signals for the steering and acceleration actuators featured by the retained racing vehicle. The results demonstrate that the trajectory is well-tracked and the signals are compatible with the actuator constraints.
Open-Loop Control Co-Design of Floating Offshore Wind Turbines Using Linear Parameter-Varying Models
Authors: Sundarrajan Athul K. , Lee Yong Hoon , Allison James T. , Herber Daniel R.
Published: November 2021

This paper discusses a framework to design elements of the plant and control systems for floating offshore wind turbines (FOWTs) in an integrated manner using linear parameter-varying models. Multiple linearized models derived from high-fidelity software are used to model the system in different operating regions characterized by the incoming wind speed. The combined model is then used to generate open-loop optimal control trajectories as part of a nested control co-design strategy that explores the system’s stability and power production in the context of crucial plant and control design decisions. A cost model is developed for the FOWT system, and the effect of plant decisions and subsequent power and stability response of the FOWT is quantified in terms of the levelized cost of energy (LCOE) for that system. The results show that the stability constraints and the plant design decisions affect the turbine’s power and, subsequently, LCOE of the system. The results indicate that a lighter plant in terms of mass can produce the same power for a lower LCOE while still satisfying the constraints.
Design of Four-Patch Multi-Stable Composite Laminates for Shape Morphing Applications
Authors: Biju Jebin , Fadel Georges , Li Suyi , Myers Oliver
Published: November 2021

Thin bistable composite laminates can be used for shape morphing applications by virtue of their material properties and asymmetric ply layup. These laminates are called bistable because they can be snapped into two or more stable shapes. A single bistable patch can result in simple cylindrical shapes and when multiple such patches are assembled into a single multi-patch laminate they result in more complex shapes and multiple stable shapes that can find wide practical use in shape morphing applications. Analytical models exist that can approximate the stable shapes of the laminates from the input of material properties and laminate geometry. And these models correlate with FEA and experiment to a satisfactory degree and could be used for the design of multi patch laminates. In this research, we make use of these analytical models that solve for a four-patch grid laminate and create a design method based on optimization to solve the reverse problem to arrive at the laminate parameters given the target shape(s). Two approaches are presented wherein one targets a single stable shape and the other targets two stable shapes which are the shapes before and after snap through. This work would be useful to understand how multi-patch laminates could be designed using optimization.
Reliability-Based Mission Planning of Off-Road Autonomous Ground Vehicles Using an Outcrossing Approach
Authors: Jiang Chen , Liu Yixuan , Hu Zhen , Mourelatos Zissimos P. , Gorsich David , Fu Yan
Published: November 2021

Reliability-based mission planning aims to identify an optimal path for off-road autonomous ground vehicles (AGVs) under uncertain terrain environment, while satisfying specific mission mobility reliability (MMR) constraints. The evaluation of MMR during path planning poses computational challenges for practical applications. This paper presents an efficient reliability-based mission planning using an outcrossing approach that has the same computational complexity as deterministic mission planning. A Gaussian random field is employed to represent the spatially dependent uncertainty sources in the terrain environment. The latter are then used in conjunction with a vehicle mobility model to generate a stochastic mobility map. Based on the stochastic mobility map, outcrossing rate maps are generated using the outcrossing concept which is widely used in time-dependent reliability. Integration of the outcrossing rate map with a rapidly-exploring random tree (RRT*) algorithm, allows for efficient path planning of AGVs subject to MMR constraints. A reliable RRT* algorithm using the outcrossing approach (RRT*-OC) is developed to implement the proposed efficient reliability-based mission planning. Results of a case study verify the accuracy and efficiency of the proposed algorithm.
Mechanical Design of a New Anthropomorphic Robot for Fastening in Wing-Box
Authors: Jiang Jiefeng , Xi Fengfeng (Jeff) , You Jingjing , Xue Qunxing
Published: November 2021

The fastener installation in the wing-box faces with narrow space, and it has to be done manually at present. Since manual labor has size constraints, the efficiency is low, and there may be assembly quality instability, it urgently needs automation. Automatic fastening assembly using a robot undoubtedly is an appropriate solution. The existing industrial robots, snake robots, humanoid robots can not meet the fastening assembly requirements in the wing-box. We develop a new anthropomorphic robot with multiple links to perform the inner fastening. A prismatic pair is employed to fit the arm links entering into the wing-box. A shaft with 360 degrees rotation liked human shoulder is introduced to meet the circumferential positioning around the process hole. Arm links are used for robotic end effector reaching the local fastening site. Based on the limitation of assembly position in the wing-box, the link lengths are considered and determined. By using the geometric relation with the link lengths, the joint angle variables are presented. Then, S shape arm link is designed for the compact requirement and the dimensions are determined based on the cross-section of human arm. Finally, stable frame structure is set up through the rear door frame and the bridge beam, and the whole robot is integrated.
Integrating Sales, Design and Production: A Configuration System for Automation in Mass Customization
Authors: Wehlin Camilla , Vidner Olle , Poot Leon , Tarkian Mehdi
Published: November 2021

Companies manufacturing customized engineer-to-order (ETO) products are decelerated by repetitive work, misinterpretations and uncoordinated processes which prohibits the achievement of mass customization. Being able to deliver customized product with low costs and fast delivery times, the concept of mass customization, is a prerequisite for maintained competitiveness with the demands from the market today. This paper presents a product configuration system (PCS) for customized products using design automation enabled by knowledge-based engineering (KBE) and enterprise-wide optimization (EWO). With this approach, the process from sales to delivery of customized products can be extensively rationalized. The PCS consists of two modules. The first being a configurator for use in the sales quotation stage. Here, customer requirements are captured, and used to generate alternatives feasible for the customer context. Thereby, correct quotations can be generated at the sales instance. The second module is the enterprise-wide configurator where accepted orders are concurrently optimized for their detailed and final design, considering the current state of the production and concurrent sales cases in the company. In other terms, instead of adapting the supply chain according to the design of the products in the order entry, the design of the products in the order entry are adapted according to the state of the supply chain. Thereby, resources can be efficiently utilized to the benefit of both the customer and the company, with reduced costs and delivery times. An implementation of the PCS in a case concerning spiral staircases, an ETO product, has shown potential of substantially reducing resources and errors and enable a reliable process supporting achievement of mass customization.