Green synthesis of diaryl selenides from arylboronic acids and arylseleninic acids.

A new method of deborylative selanylation using arylboronic acids and arylseleninic acids gave diaryl selenoethers and diarylselenoxide. The present approach requires only equimolar arylseleninic acid and led selectively to selenoethers or selenoxides depending on the solvent. The method is metal-free, base- or oxidant-free, efficient, and environmentally friendly.

Agro-waste sourced catalyst as an eco-friendly and sustainable approach for Knoevenagel condensation reaction

Background: The present work describes an eco-friendly and sustainable approach for the Knoevenagel condensation of an aromatic aldehyde with ethyl cyanoacetate, and salicylaldehyde with Meldrum acid for the synthesis of ethyl benzylidenecyanoacetate and 3-carboxy coumarin (2-oxo-2H-1-benzopyran) derivatives, respectively. The reaction performed under greener catalytic media Water Extract of Watermelon Fruit Peel Ash (WEWFPA) is an eco-friendly protocol derived from the agro-waste feedstock. Various protocols have been reported for the synthesis of Knoevenagel condensation reaction using a hazardous catalyst or/and solvent found toxic to the environment, reaction time longer, poor yield, and required purification of the final product. The present method provides several added advantages of being completely greener, economic, giving high yield, inexpensive catalyst, and the final product isolated in pure form with good yield. Objective: The objective of the study was to develop a green methodology for the synthesis of ethyl benzylidenecyanoacetate and 3-carboxy coumarin derivatives. Results: The agro-waste based catalyst developed avoids the use of external inorganic/organic base, additives, and solvent-free synthesis of Knoevenagel condensation of ethyl benzylidenecyanoacetate and 3-carboxy coumarin derivatives under rt and microwave irradiation, respectively described. The microwave irradiation condition requires less time for the completion of the reaction and also gave better yield isolation Methods: We have demonstrated WEWFPA as a greener homogenous agro-waste is employed under rt stirring and microwave irradiation for the economic synthesis of ethyl benzylidenecyanoacetate and 3-carboxy coumarin derivatives. The developed method was found robust, non-hazardous and solvent-free with simple work-up gave target product. Conclusion: In conclusion, we have established an efficient, simple, agro-waste based catalytic approach for the synthesis of ethylbenzylidenecyanoacetate and 3-carboxy coumarin derivatives employing WEWFPA as an efficient catalyst under rt stirring and microwave synthesis, respectively. The method is a greener, economical and eco-friendly approach for the synthesis of Knoevenagel condensation products. The advantages of the present approach are solvent-free, no external metal, chemical base free, short reaction time and isolated product in good to excellent yields. The catalyst is agro-waste derived, which has abundant in natural sources, thus making the present approach a greener one.

General Properties of Higher-Spin Fermion Interaction Currents and Their Test in πN-Scattering

The currents of higher-spin fermion interactions with zero- and half-spin particles are derived. They can be used for the N*(J) ↔ Nπ-transitions (N*(J) is thenucleon resonance with the J spin). In accordance with the theorem on currents and fields, the spin-tensors of these currents are traceless, and their products with the γ-matrices and the higher-spin fermion momentum vanish, similarly to the field spin-tensors. Such currents are derived explicitly for J=3/2and 5/2. It is shown that, in the present approach, the scale dimension of a higher spin fermion propagator equals to –1 for any J ≥ 1/2. The calculations indicate that the off-mass-shell N* contributions to the s-channel amplitudes correspond to J = JπN only ( JπN is the total angular momentum of the πN-system). As contrast, in the usually exploited approaches, such non-zero amplitudes correspond to 1/2 ≤ JπN ≤ J. In particular, the usually exploited approaches give non-zero off-mass-shell contributions of the ∆(1232)-resonance to the amplitudes S31, P31( JπN = 1/2) and P33, D33(JπN = 3/2), but our approach – to P33 and D33 only. The comparison of these results with the data of the partial wave analysis on the S31-amplitude in the ∆(1232)-region shows the better agreement for the present approach.

Hetero-Type Benzannulation Leading to Substituted Benzothio-Phenes

TiCl4 (or SnCl4)-promoted hetero-type benzannulation reactions using various (2,2-dichlorocyclopropyl)(thiophen-2-yl)methanols proceeded smoothly to produce uniquely substituted 4-chlorobenzothiophenes (five examples). The present approach involves the first distinctive thiophene formation from thiophene cores, in contrast to traditional methods of thiophene formation from benzene cores. The stereocongested (less reactive) Cl position in the obtained 4-chlorobenzothiophenes functioned successfully as the partners of three cross-coupling reactions: (i) a Suzuki–Miyaura cross-couplings using Pd(OAc)2/SPhos/K3PO4 catalysis (seven examples; 63–91%), (ii) a hydroxylation using KOH/Pd(dba)2/tBu-XPhos catalysis (85%), and (iii) a borylation using a B2(pin)2/Pd(dba)2/XPhos/NaOAc catalysis-provided 4-(pin)B-benzothiophene (58%).

Cultural Education towards Exclusivism. Or, the Role of Education in shaping Exclusivism

The way in which the “traditional” system of education ends up deflecting people's attention from the things that make us, human beings, a whole, a species, and a unity, is constantly and ascendingly challenged and thought against. Currently, we need to find out what features of the former educational system, especially those institutionalized, maintained by the school and society, are highlighted here to be eliminated and what is their authentic value in the system. In the present approach, we will refer, as an example, to religious education. These characteristics that we intend to discuss here do not target a “radical” pedagogy but question the educational system in relation to the inclusion-exclusion binomial. The stereotype, bias, and pretentious choices strained by exclusivism through education actually dehumanize us and stress on features that do not honor us. Is it possible to ever lose them along with all their harmful social consequences?

MQTT-PRESENT: Approach to secure internet of things applications using MQTT protocol

The big challenge to raise for deploying the application's domain of the Internet of Things is security. As one of the popular messaging protocols in the IoT world, the message queue telemetry transport (MQTT) is designed for constrained devices and machine-to-machine communications, based on the publish-subscribe model, it offers a basic authentication using username and password. However, this authentication method might have a problem in terms of security and scalability. In this paper, we provide an analysis of the current research in the literature related to the security for the MQTT protocol, before we give a brief description of each algorithm used on our approach, to finally propose a new approach to secure this protocol based on AugPAKE algorithm and PRESENT encryption. This solution provides mutual authentication between the broker and their clients (publishers and subscribers), the confidentiality of the published message is protected twice, the integrity and non-repudiation of MQTT messages which is protected during the process of transmission.

A Binary Quantifier for Definite Descriptions for Cut Free Free Logics

This paper presents rules in sequent calculus for a binary quantifier I to formalise definite descriptions: Ix[F, G] means ‘The F is G’. The rules are suitable to be added to a system of positive free logic. The paper extends the proof of a cut elimination theorem for this system by Indrzejczak by proving the cases for the rules of I. There are also brief comparisons of the present approach to the more common one that formalises definite descriptions with a term forming operator. In the final section rules for I for negative free and classical logic are also mentioned.

CHARACTERIZATION OF TRAILING EDGE BROADBAND NOISE FROM WIND TURBINE BLADES

Wind turbine noise is a critical issue for siting and its operation in offshore and terrestrial conditions. In this work, we analysed trailing edge bluntness vortex shedding noise source for a land based turbine of size 2MW and blade span of 38m using modified BPM noise solver. A regression approach has been implemented to predict the shape function in terms of thickness to chord ratio of aerofoils used for blade. For trailing edge height of 1 % chord, computations for sound power level were done at wind speed of 8m/s, 17 RPM, and showed that present regression approach predicts the noise peak of 78dBA at f ~ 10 kHz. These results were also validated using experiment data from GE 1.5sle, Siemens 2.3MW turbines with blade lengths of 78 -101m and agreed within 2 % at very high frequencies, f > 5kHz. In addition, results from present approach agreed with original BPM and modified BPM by Wei et al at high frequencies, f ~ 10kHz where the bluntness noise becomes predominant. The slope of noise curves from present approach, and modified BPM methods are lower when compared with original BPM and show sound level coincidence with peak Strouhal number of ~ 3.3.

The gender system of Durop

This paper presents an analysis of grammatical gender and agreement in Durop, a language of the Upper Cross subgroup of Cross River. The data used are drawn from Kastelein (Kastelein, Bianca. 1994. A phonological and grammatical sketch of DuRop. Leiden: University of Leiden Scriptie), whose analysis treats gender as the singular – plural pairings of nouns different from the present approach. Kastelein identifies eight concord classes (agreement classes); these form the basis of gender in Durop in the present analysis; as many as 24 agreement classes are identified here. The various systems comprising nominal classification, agreement and gender in Durop are compared and discussed. The agreement system comprises three subsystems of differing numbers of agreement classes.