scholarly journals Stabilization of the Surface of ZnO Films and Elimination of the Aging Effect

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6535
Author(s):  
Khabibulla A. Abdullin ◽  
Maratbek T. Gabdullin ◽  
Sultan K. Zhumagulov ◽  
Guzal A. Ismailova ◽  
Lesya V. Gritsenko ◽  
...  
Keyword(s):  
Aging Effect ◽  
Degradation Process ◽  
Zno Films ◽  
Hydrogen Passivation ◽  
Nanorod Arrays ◽  
Short Term ◽  
Surface Sites ◽  
O2 Adsorption ◽  
Multifunctional Material ◽  
Different Types

Zinc oxide is a promising multifunctional material. The practical use of nano- and polycrystalline ZnO devices faces a serious problem of instability of electrical and luminescent characteristics, due to the adsorption of oxygen by the surface during aging. In this paper, the aging effect in ZnO films and nanorod arrays was studied. It was found that ZnO samples demonstrate different behavior of the degradation process, which corresponds to at least two different types of adsorbing surface sites for O2, where O2 adsorption is of a different nature. The first type of surface sites is rapidly depassivated after hydrogen passivation and the aging effect takes place due to these centers. The second type of surface sites has a stable structure after hydrogen passivation and corresponds to HO–ZnO sites. The XPS components of these sites include the Zn2p3/2 peak at 1022.2 ± 0.2 eV and Zn2p1/2 peak at 1045.2 ± 0.2 eV, with a part of the XPS O1s peak at 531.5 ± 0.3 eV. The annealing transforms the first type of site into the second one, and the subsequent short-term plasma treatment in hydrogen results in steady passivation, where the degradation of characteristics is practically reduced to zero.

Comprehensive Effects of Short-Term Rental Platforms Across Hotel Types in U.S. and International Destinations

2021 ◽  
pp. 193896552110335
Author(s):  
John W. O’Neill ◽  
Jihwan Yeon
Keyword(s):  
Service Providers ◽  
Comprehensive Analysis ◽  
Competitive Market ◽  
Substitution Effects ◽  
Short Term ◽  
Hotel Performance ◽  
The World ◽  
Different Types ◽  
Location Type ◽  
The Impact

In recent years, short-term rental platforms in the lodging sector, including Airbnb, VRBO, and HomeAway, have received extensive attention and emerged as potentially alternative suppliers of services traditionally provided by established commercial accommodation providers, that is, hotels. Short-term rentals have dramatically increased the available supply of rooms for visitors to multiple international destinations, potentially siphoning demand away from hotels to short-term rental businesses. In a competitive market, an increase in supply with constant demand would negatively influence incumbent service providers. In this article, we examine the substitution effects of short-term rental supply on hotel performance in different cities around the world. Specifically, we comprehensively investigate the substitution effects of short-term rental supply on hotel performance based on hotel class, location type, and region. Furthermore, we segment the short-term rental supply based on its types of accommodations, that is, shared rooms, private rooms, and entire homes, and both examine and quantify the differential effects of these types of short-term rentals on different types of hotels. This study offers a comprehensive analysis regarding the impact of multiple short-term rental platforms on hotel performance and offers both conceptual and practical insights regarding the nature and extent of the effects that were identified.

scholarly journals Duration of Short-term Effects of PNF According to Different Types of Joint Movement

2012 ◽  
Vol 27 (5) ◽  
pp. 589-592
Author(s):  
Katsuyuki KATOU ◽  
Hitoshi MARUYAMA
Keyword(s):  
Joint Movement ◽  
Short Term ◽  
Different Types ◽  
Short Term Effects

Morbidity of in-hospital purulent-septic infections of adults patients after different types of endovascular cardiosurgical operations

2020 ◽  
pp. 13-19
Author(s):  
Viktor Ivanovich Sergevnin ◽  
Larisa Gennadievna Kudryavtseva ◽  
Anna Igorevna Zolotukhina
Keyword(s):  
Medical Records ◽  
Heart Surgery ◽  
Surgical Intervention ◽  
Heart Rhythm ◽  
Community Acquired Pneumonia ◽  
Short Term ◽  
Intervention Community ◽  
Duration Of Surgery ◽  
Different Types ◽  
Low Incidence

An estimate of the incidence of nosocomial purulent-septic infections (GSI) of adult patients after various types of closed heart surgery according to the results of a study of medical records of 3275 patients is presented. It was established that the incidence rate of typical GSI after endovascular cardiac surgery was 3.1, with prenosological forms — 3.9 per 1000 operations. The main clinical options for postoperative GSI were infections in the field of surgical intervention, community-acquired pneumonia, urinary tract infection and bloodstream infection. There were no statistically significant differences between the incidence of GSI after stenting of the coronary arteries, operations for heart rhythm disturbances, stenosis of the carotid artery and other operations. The low incidence of GSI after closed heart surgery is due to the short duration of surgery, as well as the absence or short-term resuscitation of patients.

A multifunctional material with distinct mechanochromic and piezochromic properties: π-stacking in play

2021 ◽  
Author(s):  
Zeyang Ding ◽  
Tong Lu ◽  
Changjiang Bi ◽  
Bao Li ◽  
Shitong Zhang ◽  
...  
Keyword(s):  
Organic Crystals ◽  
Multifunctional Material ◽  
Π Stacking ◽  
Different Types

Controlling different types of forces to achieve materials with different emission responses remains challenge. In this work, polymorphic organic crystals with blue (1-B) and green (1-G) emission based on N-(4-(1-cyano-2-phenylvinyl)phenyl)benzamide...

scholarly journals Integration of different-quality data in short-term mining planning

2015 ◽  
Vol 68 (2) ◽  
pp. 221-227 ◽  
Author(s):  
Cristina Paixão Araújo ◽  
João Felipe Coimbra Leite Costa
Keyword(s):  
Mineral Exploration ◽  
Quality Data ◽  
Imprecise Data ◽  
Short Term ◽  
Mining Operations ◽  
Different Types ◽  
Block Models ◽  
The Impact ◽  
Block Distribution ◽  
Ordinary Cokriging

AbstractDecisions, from mineral exploration to mining operations, are based on grade block models obtained from samples. This study evaluates the impact of using imprecise data in short-term planning. The exhaustive Walker Lake dataset is used and is considered as the source for obtaining the true grades. Initially, samples are obtained from the exhaustive dataset at regularly spaced grids of 20 × 20 m and 5 × 5 m. A relative error (imprecision) of ±25% and a 10% bias are added to the data spaced at 5 × 5 m (short-term geological data) in different scenarios. To combine these different types of data, two methodologies are investigated: cokriging and ordinary kriging. Both types of data are used to estimate blocks with the two methodologies. The grade tonnage curves and swath plots are used to compare the results against the true block grade distribution. In addition, the block misclassification is evaluated. The results show that standardized ordinary cokriging is a better methodology for imprecise and biased data and produces estimates closer to the true grade block distribution, reducing block misclassification.

scholarly journals Predicting remaining useful life of rolling bearings based on deep feature representation and long short-term memory neural network

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881718 ◽  
Author(s):  
Wentao Mao ◽  
Jianliang He ◽  
Jiamei Tang ◽  
Yuan Li
Keyword(s):  
Neural Network ◽  
Life Prediction ◽  
Short Term Memory ◽  
Degradation Process ◽  
Remaining Useful Life ◽  
Feature Representation ◽  
Short Term ◽  
Term Memory ◽  
Useful Life ◽  
Long Short Term Memory

For bearing remaining useful life prediction problem, the traditional machine-learning-based methods are generally short of feature representation ability and incapable of adaptive feature extraction. Although deep-learning-based remaining useful life prediction methods proposed in recent years can effectively extract discriminative features for bearing fault, these methods tend to less consider temporal information of fault degradation process. To solve this problem, a new remaining useful life prediction approach based on deep feature representation and long short-term memory neural network is proposed in this article. First, a new criterion, named support vector data normalized correlation coefficient, is proposed to automatically divide the whole bearing life as normal state and fast degradation state. Second, deep features of bearing fault with good representation ability can be obtained from convolutional neural network by means of the marginal spectrum in Hilbert–Huang transform of raw vibration signals and health state label. Finally, by considering the temporal information of degradation process, these features are fed into a long short-term memory neural network to construct a remaining useful life prediction model. Experiments are conducted on bearing data sets of IEEE PHM Challenge 2012. The results show the significance of performance improvement of the proposed method in terms of predictive accuracy and numerical stability.

scholarly journals A bilingual advantage in memory capacity: Assessing the roles of proficiency, number of languages acquired and age of acquisition

2020 ◽  
Author(s):  
Ezequiel Martin Durand López
Keyword(s):  
Short Term Memory ◽  
Age Of Acquisition ◽  
Memory Capacity ◽  
Span Task ◽  
Visuospatial Memory ◽  
Short Term ◽  
Term Memory ◽  
Bilingual Advantage ◽  
Different Types ◽  
L2 Learners

This study examines whether different types of bilingualism modulate memory capacity differently. More specifically, the study assesses the effects of age of acquisition, number of languages acquired and proficiency in the L2 on phonological short-term memory, visuospatial memory and semantic memory.DesignMemory capacity was measured by means of three tasks: digit span task (phonological short-term memory), Corsi block task (visuospatial memory) and word span task (semantic memory). Participants were divided into five groups based on the number of languages acquired, age of acquisition and proficiency: monolinguals, intermediate L2 learners, advanced L2 learners, simultaneous bilinguals and multilinguals.Data and analysisAnalyses of variance were used to analyze participants’ scores for each of the memory tasks.Findings and conclusionsFor the word span task, no significant differences were found among the groups, which supports the notion that semantic memory is language independent. Furthermore, intermediate and advanced L2 learners and multilinguals presented significantly higher phonological short-term memory spans compared to simultaneous bilinguals. Finally, intermediate L2 learners and multilinguals significantly outperformed monolinguals on visuospatial memory spans. Results suggest that L2 acquisition might strengthen both visuospatial and phonological short-term memory, which in turn tend to improve as L2 proficiency increases.OriginalityWhile previous studies have provided evidence of a bilingual advantage in memory capacity, these studies have generally grouped different types of bilinguals together (e.g., L2 leaners and heritage speakers). This study takes a step forward by examining differences on memory capacity across different types of bilinguals and in comparison to their monolingual peers in order to better understand the cognitive effects of bilingualism.Significance and implicationsWhen considering age of acquisition, number of languages acquired and proficiency as grouping factors, different effects of bilingualism on memory capacity can be observed. Future studies on this matter should include bilingual participants that are comparable with regard to the aforementioned variables.

scholarly journals Effects of WMA Additive on the Rheological Properties of Asphalt Binder and High Temperature Performance Grade

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Jiupeng Zhang ◽  
Guoqiang Liu ◽  
Li Xu ◽  
Jianzhong Pei
Keyword(s):  
Critical Temperature ◽  
Rheological Properties ◽  
Asphalt Binder ◽  
Aging Effect ◽  
Asphalt Binders ◽  
Short Term ◽  
Performance Grade ◽  
Temperature Performance ◽  
Effects Of Temperature ◽  
Increasing Temperature

Sasobit additives with different dosages were added into 70# and 90# virgin asphalt binders to prepare WMA binders. The rheological properties, includingG∗andδ, were measured by using DSR at the temperature ranging from 46°C to 70°C, and the effects of temperature, additive dosage and aging onG∗/sin⁡δ, critical temperature, and H-T PG were investigated. The results indicate that WMA additive improvesG∗but reducesδ, and the improvement on 70# virgin binder is more significant.G∗/sin⁡δexponentially decreases with the increasing temperature but linearly increases with the increasing additive dosage. Aging effect weakens the interaction between binder and additive but significantly increases the binder’s viscosity; that is whyG∗/sin⁡δis higher after short-term aging. In addition, the critical temperature increases with the increasing additive dosage, and the additive dosage should be more than 3% and 5% to improve H-T PG by one grade for 70# and 90# virgin binder, respectively.

Perineal Wound Closure Using Biological Mesh Following Extralevator Abdominoperineal Excision

2018 ◽  
Vol 36 (4) ◽  
pp. 281-288 ◽  
Author(s):  
Naseer Baloch ◽  
Per J. Nilsson ◽  
Caroline Nordenvall ◽  
Mirna Abraham-Nordling
Keyword(s):  
Wound Closure ◽  
Perineal Wound ◽  
Abdominoperineal Excision ◽  
Biological Mesh ◽  
Single Centre ◽  
Short Term ◽  
Perineal Reconstruction ◽  
Primary Rectal Cancer ◽  
Different Types ◽  
Electronic Hospital

Aims: This study aimed to describe the short-term perineal healing rates in patients with perineal reconstruction using a biological mesh following extralevator abdominoperineal excision (elAPE). Methods: In a retrospective, descriptive single-centre cohort study, 88 consecutive patients treated with elAPE and perineal closure using a biological mesh between January 2011 and December 2015 were reviewed. All available data from electronic hospital records was collected. Patients were followed for 1 year following surgery and perineal wound status assessed at 3 months and at 1 year. Results: In total, 63 patients were male and all but 8 patients were treated for primary rectal cancer. All patients but 3 had received radiotherapy prior to surgery. Multivisceral excisions were performed in 19 patients. Omentoplasty was performed in 55 patients and 3 different types of meshes were used during the study period. At 3 months, 58 patients (66%) had a healed perineum. No association was detected between patient, tumour or perioperative characteristics and perineal wound status at 3 months. At 1 year, 4 patients were deceased and among the remaining 84, the perineal wound was healed in 77 patients (92%). Conclusion: The use of biological meshes in perineal reconstruction following elAPE is feasible and safe, and the perineal wound is healed in the majority of the patients within 3 months.

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