Formation Of Various Networks Research Articles

Supramolecular heterosynthon assemblies of ortho-phenylenediamine with substituted aromatic carboxylic acids

Co-crystallization experiments conducted between ortho-phenylenediamine (OPDA) and five substituted aromatic acids (phthalic acid, salicylic acid, 4-hydroxybenzoic acid, 4-nitrobenzoic acid and 3,5-dinitrobenzoic acid) reveal the formation of supramolecular networks constructed from acid–base heterosynthons of ortho-phenylenediammonium cations with respective aromatic anions. All of these coformers are generally regarded as safe (GRAS) molecules. The five reported crystal structures are sustained predominantly by intermolecular N+−H...O−, N—H...O− and N—H...O hydrogen-bonding interactions; in addition intramolecular O—H...O and intermolecular O—H...O, O—H...O− and C—H...O interactions contribute to the formation of various networks. Five 1:1 salts [NH2C6H4NH3]+·[COOHC6H4COO]− (1); [NH2C6H4NH3]+·[OHC6H4COO]− (2); [{NH2C6H4NH2}2·{OHC6H4COOH}2·{NH2C6H4NH3}+ 2·{OHC6H4COO}− 2] (OPDPHB) (3); [NH2C6H4NH3]+·[NO2C6H4COO]− (4) and [NH2C6H4NH3]+·[(NO2)2C6H4COO]− (5) were isolated as single crystals by the slow evaporation method and were characterized using spectroscopic and X-ray crystallographic techniques. X-ray diffraction studies confirmed the formation of salts. The pK a difference between the amine and respective acid favours the transfer of a proton from the acid to the amine, which leads to the formation of the anion and the cation. The interactions between these ions resulted in a stable heterosynthon in each case. The asymmetric units of salts (1), (2), (4) and (5) contain one anion and one cation each, but salt (3) consists of two anions, two cations and two neutral species in its asymmetric unit. A polymorph of salt (3) was also isolated from the crystallization of the ground material from liquid-assisted grinding [{NH2C6H4NH2}·{NH2C6H4NH3}+·{OHC6H4COO}−] (OPDPHB 3P). The polymorph crystallized in the monoclinic non-centrosymmetric space group P21. The liquid-assisted grinding experiments using a 1:1 ratio also revealed the formation of the expected salts, except salt (3), where this product matches with polymorph (OPDPHB 3P).

The effect of an activation solution with siliceous species on the chemical reactivity and mechanical properties of geopolymers

Precursors are critical parameters in geopolymerization mechanisms because they govern the reaction kinetics as well as the working properties of the final materials. This study focuses on the effect of alkaline solutions on geopolymer formation. Toward this end, several geopolymer samples were synthesized from the same metakaolin and various alkaline solutions. First, the solutions were characterized by thermogravimetric analysis as well as DTA–TGA, infrared spectroscopy, and MAS-NMR spectrometry. The structural evolution of the formed geopolymers was investigated using infrared spectroscopy. The measurement of mechanical strength was tested by compression. The results provide evidence of relationships between the chemical composition, the extent of depolymerization of the alkaline solutions, the kinetics of Si–O–Si bond substitution by Si–O–Al and the compressive strength. For a given aluminosilicate source, the nature and the quantity of siliceous species in the activation solution appear to lead to variation in the reactivity and, consequently, to the formation of various networks that control the kinetics of formation of geopolymers and their mechanical properties.

Improved CBRN Preparedness and Response Through Teamwork and Knowledge Sharing

Biosecurity and Bioterrorism: Biodefense Strategy, Practice, and ScienceVol. 11, No. S1 Preparedness and ResponseOpen AccessImproved CBRN Preparedness and Response Through Teamwork and Knowledge SharingCecilia VahlbergCecilia VahlbergSearch for more papers by this authorPublished Online:24 Aug 2013https://doi.org/10.1089/bsp.2013.0862AboutSectionsPDF/EPUB ToolsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail The EU CBRN Action Plan is part of the work to strengthen and increase our ability to handle incidents involving CBRN materials. CBRN incidents have attracted a lot of attention, especially during the past decade, and efforts on both national levels (central, regional, and local) as well as the international level should be made to enhance the management of CBRN-related crises. The precautionary measures or preparedness regarding CBRN as well as the response to such an incident are important aspects to consider and are included in the EU CBRN Action Plan.Forensic evidence is critical for the prosecution and conviction of offenders in CBRN-related crimes, and consequently forensic awareness at crime scenes involving CBRN is highly important and an essential subject to consider in CBRN preparedness and response. The knowledge and experience of forensic experts, familiar with how to secure and analyze forensic evidence, can be used to increase the forensic awareness of other authorities involved in CBRN investigations, including legal authorities, CBRN subject experts, rescue services, and health agencies. It is especially important that first responders receive a proper education regarding forensic awareness to guarantee that the evidence at a CBRN crime scene is properly handled and secured.Exchange of information, knowledge, professional experience, and abilities is one approach to ensuring a high degree of expertise and competence in the CBRN area. The exchange of information may include emergency response plans, gained experiences from exercises, research results regarding CBRN agents, CBRN detection methods, knowledge regarding forensic awareness at crime scenes, and improved analysis methods of forensic evidence. Collaboration enables the exchange of information. These collaborations, both on the national and international levels, could include mutual exercises, research projects, conferences, and formation of various networks between organizations involved in the investigation of CBRN-related crime.Emergency plans should include CBRN. This is especially important for places, organizations, and arrangements that can be considered as potential CBRN targets. It is also important that forensic awareness is considered when developing or updating emergency response plans so that forensic evidence can be secured in case of a CBRN incident. Another important issue when considering CBRN preparedness is the ability to perform decontamination procedures. It is essential to have well-established routines and knowledge to be able to decontaminate an environment as well as individuals who have been exposed to CBRN agents. Decontamination procedures also make it possible to analyze forensic evidence at “normal” forensic laboratories.All in all, collaboration and exchange of information between expert agencies and authorities that might become involved in the handling of CBRN crises and the establishment and exercise of joint routines for CBRN incidents are essential for CBRN preparedness and response.FiguresReferencesRelatedDetailsCited byImplications Drawn from a Military Bioterror Exercise in Israel Tamar Berger, Itay Fogel, Lion Poles, Adi Avniel Aran, Omri Shental, and Michael Kassirer8 April 2015 | Health Security, Vol. 13, No. 2 Volume 11Issue S1Sep 2013 InformationCopyright 2013, Mary Ann Liebert, Inc.To cite this article:Cecilia Vahlberg.Improved CBRN Preparedness and Response Through Teamwork and Knowledge Sharing.Biosecurity and Bioterrorism: Biodefense Strategy, Practice, and Science.Sep 2013.S45-S45.http://doi.org/10.1089/bsp.2013.0862creative commons licensePublished in Volume: 11 Issue S1: August 24, 2013PDF download

Mapping regional structures as outlined and produced by a system of marriage ties

Kalotaszeg is a famous historic and ethnographic region in Transylvania (Romania) consisting of approximately 35–40 village communities. The region has raised considerable scholarly interest since its early discovery at the end of the 19th century. A constantly reoccurring focus of studies has been to outline the structure of the region. Although it was not our primary concern, when we started our social anthropology fi eldwork at the beginning of the 1990s we soon encountered the problematic issue of how to delineate the external and internal boundaries around and within this multi-ethnic and multi-religious region and how to grasp in-group and out-group relations with a special regard to the context of socio-historical structure of the population in the area. We wanted to understand what kinds of diachronic and synchronic factors stood behind the formation of various networks of human connection interpreted as regional structures.

Geomaterial foams: role assignment of raw materials in the network formation

The geomaterial foams studied is based on geopolymerization reactions, which is a type of geosynthesis that involves silico-aluminates. Its study during formation has however revealed a different behavior than geopolymer, suggesting the formation of various networks. This work investigates the interaction between initial compounds (metakaolin, silica fume, potassium-based solution) by a kind of mixture decomposition to ultimately understand the formation mechanism of foam. The structural evolution was determined using thermal analysis, FTIR spectroscopy and 27Al and 29Si MAS-NMR measurements. The use of different raw materials in combination with various solutions demonstrates the formation of various species in solution. The reactivity of the solution will then evolve in different ways. The Si/K ratio controlled the type of species created and, particularly, the reactivity in the mixture. From the various reactions of dissolution and polycondensation that were deduced, we could identify the composition of the four networks (K0.5SiAl0.75O6.8H8.6; K2Si2O5; KAlSi2O4,1.5H2O; and amorphous silica) constituting the foam.

:"Paper-Contestations" and Textual Communities in England, 1640-1675

The mass production and dissemination of printed materials were unparalleled in England during the 1640s and 50s. While theatrical performance traditionally defined literary culture, print steadily gained ground, becoming more prevalent and enabling the formation of various networks of writers, readers, and consumers of books. In conjunction with an evolving print culture, seventeenth-century England experienced a rise of political instability and religious dissent, the closing of the theatres, and the emergence of a middle class. Elizabeth Sauer examines how this played out in the nation?s book and print industry with an emphasis on performative writings, their materiality, reception, and their extra-judicial function.'Paper-contestations' and Textual Communities in England challenges traditional readings of literary history, offers new insights into drama and its transgression of boundaries, and proposes a fresh approach to the politics of consensus and contestation that animated seventeenth-century culture and that distinguishes current scholarly debates about this period.