Optimized Synthesis and Structural Characterization of the Borosilicate MCM-70

A structure analysis of the borosilicate zeolite MCM-70, whose synthesis had been patented in 2003, was reported in 2005. Unfortunately, that structure analysis was somewhat ambiguous. Anisotropic line broadening made it difficult to model the peak shape, some peaks in the electron density map could not be interpreted satisfactorily, the framework geometry was distorted, and MAS NMR results were partially contradictory. In an attempt to resolve some of these points, an optimization of the synthesis was undertaken, and the structure was reinvestigated. The structure was solved from synchrotron powder diffraction data collected on an as-synthesized sample (Pmn2_1, a = 13.3167(1) Å, b = 4.6604(1) Å, c = 8.7000(1) Å) using a powder charge-flipping algorithm. The framework topology, with a 1-dimensional, 10-ring channel system, is identical to the one previously reported. However, the B in this new sample was found to be ordered in the framework, fully occupying one of the four tetrahedral sites. Two extra-framework K^+ ion positions, each coordinated to five framework O atoms and one water molecule, were also found. The solid state ^(29)Si, ^(11)B and ^1H NMR results are fully consistent with this ordered structure

Factorial Validity of the Flight Risk Assessment Tool in General Aviation Operations

The Flight Risk Assessment Tool (FRAT) was developed and is recommended by the Federal Aviation Administration to provide a solution of proactively identifying and mitigating risk before each flight. General aviation (GA) operators are encouraged to adapt the FRAT based upon specific operational characteristics. Currently, most safety management systems-compliant GA operators have implemented various versions of FRATs with different operational purposes. However, the FRAT could be inappropriately implemented because of the dynamic operational features of GA operations. The purpose of this study is to explore insights into potential approaches to validate the FRAT that is used for flight risk assessment in routine GA operations. A FRAT from a flight school regulated under Title 14 Code of Federal Regulations Part 141 was used as a study case. In total, 1,832 sets of FRAT data were collected from flight operations between November 2016 and February 2017. Confirmatory factor analysis (CFA) was adopted in this research. The CFA results indicated that the studied FRAT model did not provide good fit with the root mean square error of approximation (RMSEA) = 0.13, standardized root mean square residual (SRMR) = 0.08, comparative fit index (CFI) = 0.98, and Tucker–Lewis index (TLI) = 0.98. Based on the modification indices, the studied FRAT model was restructured by removing 11 risk items from the original 33 risk items. The new model fitted the data acceptably (RMSEA = 0.07, SRMR = 0.05, TLI = 0.76, CFI = 0.69). In addition, implications and directions for further study are discussed

2,3,4-Tribromo­thio­phene

In the title compound, C4HBr3S, there are two essentially planar mol­ecules in the asymmetric unit. In the crystal structure, bifurcated C—H⋯Br hydrogen bonds link the mol­ecules into chains. Weak Br⋯Br inter­actions [Br⋯Br = 3.634 (4)–3.691 (4) Å] then lead to undulating sheets in the bc plane

2,2′-(9,9-Dioctyl-9H-fluorene-2,7-di­yl)bis­(4,4,5,5-tetra­methyl-1,3,2-dioxaborolane)

In the title compound, C41H64B2O4, one of the five-membered rings has an envelope conformation, while the other, which may be affected by disorder, is nearly coplanar with the fluorene ring. The dihedral angle between the fluorene and dioxaborolane rings is 2.29 (1)°. Two of the methyl groups are disordered over two orientations in 0.67 (3):0.33 (3) and 0.568 (10):0.432 (10) ratios

Factorial Validity of the Flight Risk Assessment Tool in General Aviation Operations

The Flight Risk Assessment Tool (FRAT) was developed and is recommended by the Federal Aviation Administration to provide a solution of proactively identifying and mitigating risk before each flight. General aviation (GA) operators are encouraged to adapt the FRAT based upon specific operational characteristics. Currently, most safety management systems-compliant GA operators have implemented various versions of FRATs with different operational purposes. However, the FRAT could be inappropriately implemented because of the dynamic operational features of GA operations. The purpose of this study is to explore insights into potential approaches to validate the FRAT that is used for flight risk assessment in routine GA operations. A FRAT from a flight school regulated under Title 14 Code of Federal Regulations Part 141 was used as a study case. In total, 1,832 sets of FRAT data were collected from flight operations between November 2016 and February 2017. Confirmatory factor analysis (CFA) was adopted in this research. The CFA results indicated that the studied FRAT model did not provide good fit with the root mean square error of approximation (RMSEA) 5 0.13, standardized root mean square residual (SRMR) 5 0.08, comparative fit index (CFI) 5 0.98, and Tucker–Lewis index (TLI) 5 0.98. Based on the modification indices, the studied FRAT model was restructured by removing 11 risk items from the original 33 risk items. The new model fitted the data acceptably (RMSEA 5 0.07, SRMR 5 0.05, TLI 5 0.76, CFI 5 0.69). In addition, implications and directions for further study are discussed

(Z)-{[3-(Hydroxy­meth­yl)-1,3-thia­zolidin-2-yl­idene]amino}formonitrile

In the title mol­ecule, C5H7N3OS, all the non-hydrogen atoms except the O atom are almost planar [maximum least squares plane deviation = 0.035 (3) Å for the N atom]. The crystal packing is stabilized by inter­molecular O—H⋯N hydrogen bonds, which link the mol­ecules into inversion dimers

(Z)-N-(3-Nicotinoyl-1,3-thia­zolidin-2-yl­idene)cyanamide

In the title compound, C10H8N4OS, the dihedral angle between the pyridine and thia­zolidine rings is 52.5 (5)°. Inter­molecular C—H⋯N inter­actions help to stabilize the crystal structure

Inkjet printed paper based frequency selective surfaces and skin mounted RFID tags: the interrelation between silver nanoparticle ink, paper substrate and low temperature sintering technique

Inkjet printing of functional frequency selective surfaces (FSS) and radio frequency identification (RFID) tags on commercial paper substrates using silver nanoparticle inks sintered using low temperature thermal, plasma and photonic techniques is reported. Printed and sintered FSS devices demonstrate performances which achieve wireless communication requirements having a forward transmission scattering parameter, S21, depth greater than ?20 dB at 13 GHz. Printed and plasma sintered RFID tags on transfer paper, which are capable of being mounted on skin, improved read distances compared to previously reported single layer transfer RFID tags fabricated by conventional thermal sintering

Comparing Statistical Methods for Constructing Large Scale Gene Networks

The gene regulatory network (GRN) reveals the regulatory relationships among genes and can provide a systematic understanding of molecular mechanisms underlying biological processes. The importance of computer simulations in understanding cellular processes is now widely accepted; a variety of algorithms have been developed to study these biological networks. The goal of this study is to provide a comprehensive evaluation and a practical guide to aid in choosing statistical methods for constructing large scale GRNs. Using both simulation studies and a real application in E. coli data, we compare different methods in terms of sensitivity and specificity in identifying the true connections and the hub genes, the ease of use, and computational speed. Our results show that these algorithms performed reasonably well, and each method has its own advantages: (1) GeneNet, WGCNA (Weighted Correlation Network Analysis), and ARACNE (Algorithm for the Reconstruction of Accurate Cellular Networks) performed well in constructing the global network structure; (2) GeneNet and SPACE (Sparse PArtial Correlation Estimation) performed well in identifying a few connections with high specificity

VFR-into-IMC: An Analysis of Two Training Protocols on Weather-Related Posttest Scores

According to the Aircraft Owners and Pilots Association Air Safety Institute, 264 accidents were identified as continued visual flight rules (VFR) into instrument meteorological conditions (IMC), during the past ten years. Approximately 89% of those VFR-into-IMC accidents were fatal, causing hundreds of deaths. VFR-into-IMC has been a major concern for the general aviation community, prompting focused efforts. Research, data analyses, outreach, training, and education are recommended practices to address risks associated with VFR-into-IMC. Researchers of the current study sought to evaluate the cause and effect relationship between two training protocols and weather-related posttest scores. A pretest–posttest experimental design was utilized at two testing locations. Participants were randomly assigned to one of three groups: a control group, an interactive online training group, or an interactive workshop group. An analysis of covariance was used to determine whether there was a significant difference between mean posttest scores among the experimental groups while controlling for pretest scores. The treatments did not appear to significantly increase posttest scores after controlling for pretest scores, at either experiment location. Though the results of this study did not yield anticipated findings, much was learned and potentially helpful to general aviation researchers seeking to mitigate VFR-into-IMC encounters. Recommendations for future research and practices are discussed