Miracle-dz/UniFAR-FTUs huggingface dataset:
The Metal−Ligand Bifunctional Catalysis: A Theoretical Study on the Ruthenium(II)-Catalyzed Hydrogen Transfer between Alcohols and Carbonyl Compounds

The ternary system consisting of [RuCl2(η6-benzene)]2, N-tosylethylenediamine or ethanolamine, and KOH (Ru:amine:KOH = 1:1:2 molar ratio) catalyzes reversible hydrogen transfer between alcohols and carbonyl compounds. The use of chiral amine auxiliaries effects asymmetric transformation. The theoretical calculations using methanol/formaldehyde transformation as the model indicates the operation of a novel metal−ligand bifunctional catalysis, which is contrary to currently accepted putative pathways. The results reveal that: (1) KOH is necessary for the generation of a formal 16-electron Ru complex, Ru(NHCH2CH2Y)(η6-benzene) (Y = O or NH) (catalyst), from an 18-electron Ru chloride, RuCl(NH2CH2CH2Y)(η6-benzene) (precatalyst), by a Dcb elimination of HCl, and not for increasing alkoxide concentration; (2) Ru alkoxides do not intervene in transfer hydrogenation; (3) the Ru alkoxide, even if formed, serves merely as a reservoir of the 16-electron catalyst; (4) the key 18-electron Ru hydride, RuH(NH2CH2CH2Y)(.
A common but not well-known cause in anal fissure development and treatment failure: Isotretinoin treatment for acne vulgaris

To investigate the underrecognized effects of isotretinoin as a cause of anal fissures (AF) and compare AF patients undergoing systemic isotretinoin treatment (SIT) and those not receiving this treatment. This study was conducted with 118 patients with newly diagnosed AF, 54 undergoing SIT (Group 1) and 64 not undergoing SIT (Group 2). The same clinical treatment modalities including first-line conservative and medical treatments during the first eight weeks, followed by interventional methods (botulinum injection or sphincterotomy) for unresponsive/recurrent cases were used for all patients. A comparative analysis was also performed. Age and body mass index (BMI) were statistically low in group 1 (p=0.003; p=0.032). Similarly, the VAS pain and Wexner constipation scores and the duration of symptoms were lower in group 1 than Group 2 (p=0.003, p
Autonomous IoT Device Management Systems: Structured Review and Generalized Cognitive Model

Research on autonomous management for large-scale deployments of constrained devices is still a maturing field in the Internet of Things (IoT). Although much research has been conducted on how to achieve autonomous management in specific cases, there is a need for literature investigating which mechanisms can achieve such behavior in a generalized way. In this review, we present a comprehensive and structured study of the mechanisms for autonomous device management of constrained IoT devices in the light of management tasks, operational environment, network topology, resource constraints, scalability and management categories. Data extracted from 32 relevant cases are first organized and analyzed according to a synthesized taxonomy of observed adaptation mechanisms, and then combined with the state-of-the-art models of autonomous operations, identifying common patterns for autonomous management. Based on our findings we substantiate best practices for designing and implementing solutions around adaptation mechanisms. We then present a generalized model for autonomous device management that describes and explains the processes required for autonomous operation, unifying the insights from previous works as one cohesive archetype.
Electrohydrodynamics-Printed Silver Nanoparticle Flexible Pressure Sensors With Improved Gauge Factor

Flexible pressure sensors (FPSs) are widely demanded for accurate pressure sensing on complex surfaces. FPSs using metal nanoparticles (NPs) as the sensing material have high conductivity and good mechanical properties, but poor gauge factor as a trade-off. In this work, a novel design of the AgNP-based FPS is proposed and testified with the help of the electrohydrodynamics-printing technology, so that the gauge factor can be improved from 8 to 286.8, resulting from the localized micro-zone piezoresistance effect. The working principle of the piezoresistive characteristic is discussed, and two methods to further improve and adjust the gauge factor are proposed and experimentally demonstrated.
Raman study of KMnF3 perovskite crystals doped by Na+

Abstract A study of the influence of cationic Na+ substitution in the archetype KMnF3 perovskite crystal was performed using the Raman method. The Raman spectra of mixed K1-xNaxMnF3 crystals with x = 0.029, 0.048 and 0.065 were recorded versus temperature and fully interpreted in terms of a “one mode” behaviour. In addition to the soft mode not completely vanishing close to Tc, attention was especially paid to evidence of static and dynamical disorder. From this point of view the behaviour of the hard Raman modes versus temperature has been studied together with two unexpected Raman bands in the cubic phase. The interpretation has been made within the more general framework of structural disorder existing in such perovskites with anisotropic interactions.
Impacts of pore size distribution on gas injection in intraformational water zones in oil sands reservoirs

Intraformational water zones are widely reported in Canadian oil sands fields. In order to pressurize a thief zone, one of the initiatives is to inject gas. However, the evaluation of gas injectivity based on a pore size distribution is still a big challenge. This study provides a multi-scale approach to study the effect of a pore size distribution on gas injectivity in intraformational water zones. The results indicate the gas effective permeability increases in a less complex and more discrete pore network. The enhancement of gas effective permeability with increased gas saturation weakens with higher complexity and lower discreteness of a pore network. A less complex and more discrete pore network better benefits the gas injectivity index.
Variational data assimilation for tropospheric chemistry modeling

The method of variational adjoint data assimilation has been applied to assimilate chemistry observations into a comprehensive tropospheric gas phase model. The rationale of this method is to find the correct initial values for a subsequent atmospheric chemistry model run when observations scattered in time are available. The variational adjoint technique is esteemed to be a promising tool for future advanced meteorological forecasting. The stimulating experience gained with the application of four-dimensional variational data assimilation in this research area has motivated the attempt to apply the technique to air quality modeling and analysis of the chemical state of the atmosphere. The present study describes the development and application of the adjoint of the second-generation regional acid deposition model gas phase mechanism, which is used in the European air pollution dispersion model system. Performance results of the assimilation scheme using both model-generated data and real observations are presented for tropospheric conditions. In the former case it is demonstrated that time series of only few or even one measured key species convey sufficient information to improve considerably the analysis of unobserved species which are directly coupled with the observed species. In the latter case a Lagrangian approach is adopted where trajectory calculations between two comprehensively furnished measurement sites are carried out. The method allows us to analyze initial data for air pollution modeling even when only sparse observations are available. Besides remarkable improvements of the model performance by properly analyzed initial concentrations, it is shown that the adjoint algorithm offers the feasibility to estimate the sensitivity of ozone concentrations relative to its precursors.
Investigation of Biosorption Behavior of Methylene Blue on Pleurotus ostreatus (Jacq. ) P. Kumm

The effect of varying parameters such as dye concentration, adsorbent dose, pH and temperature on the adsorption capacity of Pleurotus ostreatus is investigated. The commonly available white rot fungus Pleurotus ostreatus is investigated as a viable biomaterial for the biological treatment of synthetic basic methylene blue effluents. The results obtained from the batch experiments reveal the ability of the fungus to remove methylene blue. The performance is dependent on the dye concentration, pH, and fungal biomass. The equilibrium and kinetics of adsorption are investigated and the Langmuir equation is used to fit the equilibrium isotherm. The adsorption isotherm of methylene blue follows only the Langmuir model with a correlation coefficient of ca. 0.96-0.99. The maximum adsorption capacity is ca. 70 mg of dye per g of dry fungus at pH 11, 70 mg L -1 dye, and 0.1 g L -1 fungus concentration, respectively. This study demonstrates that the fungus could be used as an effective biosorbent for the treatment of dye-containing wastewater streams.
On the Response of Polarimetric GNSS-Reflectometry to Sea Surface Roughness

Reflectometry of Global Navigation Satellite Systems (GNSS) signals from the ocean surface has provided a new source of observations to study the ocean–atmosphere interaction. We investigate the sensitivity and performance of GNSS-Reflectometry (GNSS-R) data to retrieve sea surface roughness (SSR) as an indicator of sea state. A data set of one-year observations in 2016 is acquired from a coastal GNSS-R experiment in Onsala, Sweden. The experiment exploits two sea-looking antennas with right- and left-hand circular polarizations (RHCP and LHCP). The interference of the direct and reflected signals captured by the antennas is used by a GNSS-R receiver to generate complex interferometric fringes. We process the interferometric observations to estimate the contributions of direct signals and reflections to the total power. The power estimates are inverted to the SSR using the state-of-the-art model. The roughness measurements from the RHCP and LHCP links are evaluated against match-up wind measurements obtained from the nearest meteorological station. The results report on successful roughness retrieval with overall correlations of 0.76 for both links. However, the roughness effect in LHCP observations is more pronounced. The influence of surrounding complex coastlines and the wind direction dependence are discussed. The analysis reveals that the winds blowing from land have minimal impact on the roughness due to limited fetch. A clear improvement of roughness estimates with an overall correlation of 0.82 is observed for combined polarimetric observations from the RHCP and LHCP links. The combined observations can also improve the sensitivity of GNSS-R measurements to the change of sea state.
Specific Quality of Service Constrained Optimal Allocation of Transmit Power in Uplink Cognitive OFDMA System

This paper investigates an optimal allocation of transmit power for uplink cognitive OFDMA system. The aim is to construct two optimization frameworks namely, framework-I and II for uplink cognitive OFDMA system that minimizes it’s transmit power while maintaining Quality of Service (QoS). The measures for QoS include SNR threshold for framework-I whereas, for framework-II, it is measured by minimum rate requirement (bits/sec/Hz) to obtain a certain bit error rate (BER). Simulation results reveal the effectiveness of the proposed frameworks. Additionally, for framework-I, effects of different SNR threshold and users’ power budget are observed on the allocation of transmit power. Whereas, for framework-II, effects of different target BER, users’ power budget and minimum rate requirement are observed on the allocation of transmit power. Results are also compared with the results obtained from conventional capacity maximization based resource allocation approaches in terms of allocated transmit power, energy efficiency (EE) and spectral efficiency (SE). Simulation results reveal that, the proposed frameworks are incredibly successful in terms of utilization of power budget of users and EE compared to conventional capacity maximization based resource allocation approaches.
Maximum repetition rate in a large cross-sectional sample of typically developing Dutch-speaking children

Abstract Purpose: The current study aims to provide normative data for the maximum repetition rate (MRR) development of Dutch-speaking children based on a large cross-sectional study using a standardised protocol. Method: A group of 1014 typically developing children aged 3;0 to 6;11 years performed the MRR task of the Computer Articulation Instrument (CAI). The number of syllables per second was calculated for mono-, bi-, and trisyllabic sequences (MRR-pa, MRR-ta, MRR-ka, MRR-pata, MRR-taka, MRR-pataka). A two-way mixed ANOVA was conducted to compare the effects of age and gender on MRR scores in different MRR sequences. Result: The data analysis showed that overall MRR scores were affected by age group, gender and MRR sequence. For all MRR sequences the MRR increased significantly with age. MRR-pa was the fastest sequence, followed by respectively MRR-ta, MRR-pata, MRR-taka, MRR-ka and MRR-pataka. Overall MRR scores were higher for boys than for girls, for all MRR sequences. Conclusion: This study presents normative data of MRR of Dutch-speaking children aged 3;0 to 6;11 years. These norms might be useful in clinical practice to differentiate children with speech sound disorders from typically developing children. More research on this topic is necessary. It is also suggested to collect normative data for other individual languages, using the same protocol.
A Low-Cost Two-Tier Fog Computing Testbed for Streaming IoT-Based Applications

In this article, we propose a comprehensive multilayer (IoT-device, edge, fog, and cloud) streaming analytics platform with two-tier fog layer, which comprises streaming and analytics tiers. The approach, functionally validated on a testbed of clusters of low-cost off-the-shelf components, demonstrates that both real-time streaming processing and large-scale data analytics are feasible, with even completely avoiding the use of cloud layer. The fog layer uses advanced streaming and analytics paradigms, such as Apache Kafka, Apache Spark, and Hadoop, to support the effective development of applications that use streaming, long-term data storage and analytics. As such, the platform is suitable for and is affordable for “private” users. Furthermore, we add to the platform intelligent edge layer that abstracts and can simulate the operation of the IoT-device layer in real time or can be directly connected to the IoT-device layer. The experiments on a real-life IoT-based smart parking application show that our two-tier approach is cost effective and scalable, and can handle simultaneously streaming processing and analytics tasks successfully.
Tetraphenylphosphonium tetrakis(1-methyl-1,2,3,4-tetrazole-5-thiolato-S)aurate(III) hemihydate

The tetraphenylphosphonium salt of tetrakis(1-methyl-1,2,3,4-tetrazole-5-thiolato)aurate(III) crystallizes as an H 2 O hemisolvate, (C 24 H 20 P)[Au(C 2 H 3 N 4 S) 4 ]. 0.5H 2 O, in the monoclinic C2/c space group, with the Au atom situated on an inversion centre. The tetrazole rings are arranged almost orthogonally with respect to the square coordination sphere. Au-S-C angles of 106.2(1) and 107.1 (1)° were found.
Theory Building, Case Dependence, and Researchers’ Bounded Rationality: An Illustration From Studies of Innovation Diffusion

Researchers increasingly take advantage of the comparative case design to build theory, but the degree of case dependence is occasionally discussed and theorized. We suggest that the comparative case study design might be subject to an often underappreciated threat—dependence across cases—under certain conditions. Using research on innovation diffusion as an illustration, we explore the role of social linkages across cases when building theory through comparison and contrast between cases. We develop an agent-based simulation, grounded by comparative case research about innovation diffusion, as novel way to study the implications of case dependence in theory building using multiple-case study research. Our simulation results suggest that the degree of case dependence has a nontrivial bearing on innovation diffusion experienced by case entities, specifically when the researcher draws a few case entities operating in a highly interconnected industry. Under these conditions, overlooking the degree of case dependence might weaken newly built theory against commonly held standards of internal validity and external validity in inductive research. We conceptualize the issue of case dependence as a concern about researchers’ bounded rationality. Accordingly, we build on our findings to provide actionable advice aiming to alleviate this concern while being amendable to the variety of approaches to build theory from multiple cases in social sciences.
Audio Content Classification Method Research Based on Two-step Strategy

Audio content classification is an interesting and significant issue. Audio classification technique has two basic parts: audio feature extraction and classifier. In general the audio content classification method is firstly to identify the original audio into text, then use the identified text to classify. But the text recognition rate is not high, some words that good for classification are identified by mistake causing that the classification effect is not ideal. In order to solve these problems above, this paper proposes a new effective audio classification method based on two-step strategy. In the first step the features are extracted by using the improved mutual information and classified with Naive Bayes classifier. After classification of the first step, an unreliable area is determined, and samples with features in this area go on to be classified with the second step. In the second step, textual features extracted with CHI statistic method are used to build a text feature space model. Then audio features containing MFCC and frame energy are combined together with the text features to build a new feature vector space model. Finally, the new feature vector space model is classified using Support Vector Machine (SVM) classifier. The experiments show that the two-step strategy classification method for audio classification achieves great classification performance with the accuracy rate of 97.2%. Keywords—Two-step Strategy; Audio classification; MFCC; Frame energy; Naive Byes; Support vector machine (SVM)
SURFER: A Secure SDN-Based Routing Protocol for Internet of Vehicles

Software-defined networking (SDN) is becoming the most dominant method for network management. By decoupling the control plane from the data plane, SDN provides a centralized view and more flexibility, scalability, and global knowledge of the network. In a previous paper, we presented ROAMER, a routing protocol that exploits roadside units (RSUs) in order to route messages within vehicular ad hoc networks (VANETs). ROAMER combines two famous routing methods that have been extensively used in VANETs, which are geographical and carry-and-forward. In this article, we upgrade ROAMER by shifting the routing operations into the SDN. Hence, we present SURFER, a routing protocol for the Internet of Vehicles (IoV) that makes use of a distributed SDN architecture and a Blockchain system within the RSU network in order to route packets securely and efficiently. We present two implementation methods for SURFER: the first uses SDN within the RSU network only, while the second method deploys SDN within the entire IoV. We implemented extensive simulations and compared SURFER to some very recent routing protocols for IoV. The simulation results illustrated the high efficiency of SURFER as compared to other IoV routing protocols in terms of latency, packet delivery, and network overhead.
Impregnation and Characterization of High Performance Extraction Columns for Separation of Metal Ions

Impregnation behaviors of reverse-phase silica materials and C18-silica HPLC columns were studied using di-(2-ethylhexyl)phosphoric acid (HDEHP) as a model extractant. Initially, the adsorption efficiency of the ligand on different types of bulk particles was investigated using various concentration of HDEHP in different composition of methanol/water mixtures based on a batch technique. Subsequently, impregnation of HPLC columns was performed using the dynamic flow-through technique. The experimental data fitted well to the Langmuir model and the adsorption isotherms from the flow-through experiment were used to prepare extraction columns of different ligand densities. Finally, the impregnated columns were characterized and validated through HPLC separation of the lanthanides.
Hyperpolarizability density analysis of the enhancement of second hyperpolarizability of π-conjugated oligomers by intermolecular interaction

In a previous paper we found that the cofacial intermolecular π–π orbital interaction in stacking dimers significantly changes the longitudinal second hyperpolarizability (γ) of the isolated monomer. On the basis of this result, we investigate the longitudinal γ values of π-conjugated main chains (CnHn+2, 6 ≤ n ≤ 16) interacting in both-end regions with two small-size cationic perturbing π-conjugated molecules, that is, allyl cations (C3H). These interacting model systems exhibit remarkable enhancement of γ values as compared with those of isolated main chains in the whole chain-length region. The γ density analysis reveals that this enhancement is described by the virtual charge transfer between both-end perturbing molecules via the main chain. The analysis of orbital correlation diagram between the perturbing molecules and main chain molecule also clarifies that such feature of γ density distribution originates in the “weak intermolecular antibondinglike coupling” between the (lowest unoccupied molecular orbital [LUMO], LUMO+1) of cationic perturbing molecules and (highest unoccupied molecular orbital [HOMO], HOMO−1) of main chain molecule. The current result suggests the possibility of novel nano-size control of nonlinear optical (NLO) properties by adjusting the intermolecular orbital interactions between the main molecule and perturbing molecules. A possible control scheme of longitudinal γ for novel intermolecular interacting NLO systems using modified DNA wires is also proposed. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Antibiotic sensitivity profile of Staphylococcus aureus isolated from HIV/AIDS patients presenting with pyoderma, at the Yaounde Central Hospital, Cameroon

Introduction the purpose of this study was to evaluate the in vitro activity of several antibiotics against strains of Staphylococcus aureus isolated from pyoderma in people living with Human Immunodeficiency Virus (HIV), consulting at the day clinic of the Yaoundé Central Hospital. Methods this was a prospective, cross-sectional study which was carried out in five months (November 2013-March 2014). Fifty-three (53) pus specimens were collected; from which the isolation of Staphylococcus aureus was made using Chapman agar. Mannitol fermentation, catalase, coagulase and DNase tests were used for species identification. Antibiotic sensitivity of each strain was determined by the agar diffusion method. Results forty-eight (48) strains of Staphylococcus aureus were isolated (90.56%). A high rate of sensitivity to antibiotics was observed in many strains: vancomycin (100.0%), pristinamycin (100.0%), chloramphenicol (100.0%), oxacillin (97.9%), cefoxitin (97.9%), gentamicin (87.5%), tobramycin (83.3%). However, some strains had strong resistance to penicillin G (89.6%) and cotrimoxazole (64.6%). The proportion of Methicilin Resistant strains of Staphylococcus aureus (MRSA) was low (2.0%). The kanamycin-tobramycin-gentamycin phenotype (KTG) was most common in the aminoglycosides resistant strains; the same as the induced phenotype E stains (iMLSB) in macrolides resistant strains. Conclusion: these results indicate that many of these antibiotics tested are still effective against strains of Staphylococcus aureus.