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Single use bioreactors (SUB) are recurrently adopted within the pharmaceutical industry since they offer several advantages with respect to traditional bioreactors. Generally, they consist of a stainless-steel container with a bag and an integrated impeller for handling (mixing stage), storage (post mixing stage I) and transfer (post mixing stage II) of formulated products. In this work, one of the single use bioreactor types, the Flexel-Levmixer by Sartorius, is investigated. It is a vessel with a square section stirred with a bottom impeller, for which little information is available in the literature, thus making troubleshooting and optimization difficult. To address this issue, a combination of experimental techniques, namely Particle Image Velocimetry, and torque sensors based on strain gauges, are selected for the investigation aimed at the understanding of the fluid dynamics and power consumption with different filling levels and impeller speeds.

The development of greener and atom economical methods for carbon‐heteroatom (C−Het) bond formation is of significant importance in synthetic organic chemistry. In this regard, metal‐free cross‐dehydrogenative coupling (CDC) represents an attractive approach as it is more facile and environment friendly. This review intends to focus on the recent developments in metal‐free CDC reactions for C−Het bond formation leading to the synthesis Carbon‐heteroatom {C−Het [(C−N), (C−O), (C−S), (C−P)]} bond formation reactions holds a significant position in synthetic organic chemistry. These reactions are used in the synthesis of pharmaceuticals, bioactive molecules and agrochemicals etc. Cross‐Dehydrogenative Coupling under transition‐metal‐free conditions has emerged as a powerful tool to achieve this bond formation by the oxidation of inert C−H and H−X bonds. This review highlights the recent efforts in the construction of C−X bond under oxidative conditions in the absence of a metal salt thereby focussing on green and sustainable practices.

In recent past, dialkyl azodicarboxylates have been embraced as versatile reagents in synthetic strategies other than Mitsunobu reactions. These azo compounds have been utilized as an oxidant or dehydrogenating reagent in oxidative transformations, such as cross dehydrogenative coupling, oxidative Ugi‐type reaction, dehydrogenation etc. Moreover, they have been utilized in different types of bond construction like C‐Heteroatom (C‐Het) and S−N bond. Very recently, these azo compounds have also been explored in photochemical reactions. Such types of reported reactions and their reaction pathways are presented here in this minireview, which manifested the oxidative abilities and advantageous features of dialkyl azodicarboxylates. An all‐rounder reagent. A brief summary of recent organic transformations mediated by dialkyl azodicarboxylates, popularly known for Mitsunobu reaction, is given in this minireview. Moreover, synthetic procedures and reaction pathways of these selected reactions are also highlighted.

C-1 substituted tetrahydroisoquinolines have emerged as important scaffolds in pharmaceutical and medical research. Although various methods for α-substitution on tetrahydroisoquinolines have been discovered, the introduction of the azole group at C-1 position remains a challenge. Recently, direct C-H activation methods and multicomponent reactions have been employed towards the synthesis of azole containing tetrahydroisoquinolines. A summary of such synthetic strategies is presented here as these promising methods can help in developing more efficient synthetic routes. This minireview covers the available synthetic methods and their mechanistic pathways for the preparation of C-1 azole substituted tetrahydroisoquinolines.

Flood is a common natural disaster in the world. Flood often takes place around the river and plains, which indicates a higher risk of flooding in these areas. In order to represent the consequences (affected area, the number of deaths, housing collapse, direct economic losses) of flood disaster picture fuzzy sets have been used. Picture fuzzy sets are the extensions of intuitionistic fuzzy sets. Picture fuzzy sets based models may be adequate in situations when we face human opinions involving more answers of the type: yes, abstain, no, refusal. In this paper, we propose several distance and similarity measures for picture fuzzy sets which considers the degree of positive membership, degree of neutral membership, the degree of negative membership and degree of refusal membership. Geometrical interpretation of the picture fuzzy sets has been investigated. On the basis of proposed similarity measures a clustering algorithm is adopts to assess flood disaster risk in South region of India. A case study of 2009 Indian flood is captured to investigate the risk analysis of flood disaster considering some important criterion such as affected area, the number of deaths, housing collapse and direct economic losses.

Dual hesitant fuzzy set, first proposed by Zhu et al. (Dual hesitant fuzzy sets, J Appl Math, 1–13, 2012) as an extension of hesitant fuzzy sets, which encompass fuzzy sets, intuitionistic fuzzy sets, hesitant fuzzy sets, and fuzzy multisets as a special case. Dual hesitant fuzzy sets consist of two parts, that is, the membership and nonmembership degrees, which are represented by two sets of possible values. Therefore, in accordance with the practical demand, these sets are more flexible than the existing fuzzy sets, and provide much more information about the situation. In this paper, the axiom definition of distance and similarity measures between dual hesitant fuzzy sets is introduced. Some new distance and similarity measures based on the geometric distance model, the set-theoretic approach, and the matching functions are proposed. The proposed distance measures are then applied to the multiple-attribute decision making under dual hesitant fuzzy environments. Through the distance measure between each alternative and the ideal alternative, the ranking order of all alternatives can be determined and the best alternative can be easily identified as well. Finally, a practical example of investment alternatives is given to demonstrate the effectiveness of the developed measures. The advantages of the proposed distance measure over existing measures have been presented.

In multicarrier modulation scheme, PAPR reduction is the main problem. Techniques mentioned in literature are either too complex or not optimal. In this paper, an attempt has been made to reduce the PAPR of multi carrier modulation with the much less complexity. Wavelet packet-based orthogonal frequency division multiplexing has been employed with orthogonal subcarriers and similarly to OFDM high spectral efficiency is achieved in WP-OFDM by the overlapping subcarriers spectra. Further, PSO-based PTS techniques have been used to reduce the PAPR with much less complexity as compared to conventional optimal PTS technique in which search complexity increases exponentially. The performance of WP-OFDM for PTS technique and PSO-based PTS techniques have been implemented in this paper. Also, the simulation results are obtained shows that the PAPR is reduced significantly with much less search complexity.

In this paper, we propose some distance measures between type-2 fuzzy sets, and also a new family of utmost distance measures are presented. Several properties of different proposed distance measures have been introduced. Also, we have introduced a new ranking method for the ordering of type-2 fuzzy sets based on the proposed distance measure. The proposed ranking method satisfies the reasonable properties for the ordering of fuzzy quantities. Some properties such as robustness, order relation have been presented. Limitations of existing ranking methods have been studied. Further for practical use, a new method for selecting the best alternative, for group decision making problems is proposed. This method is illustrated with a numerical example.

The main aim of this paper is to propose a new approach for the ranking of exponential vague sets. The concepts of exponential vague sets and arithmetic operations between two exponential vague sets are introduced. The shortcomings of some existing ranking approaches for the ranking of generalized fuzzy sets and intuitionistic fuzzy numbers are pointed out. The proposed method consider not only the rank but also the decision maker optimistic attitude and it is shown that proposed ranking approach is more intuitive and reasonable as compared to existing ranking approaches. Also the proposed ranking function satisfies the reasonable properties for the ordering of fuzzy quantity. For practical use, proposed ranking approach is applied to decision making problem.

A novel route to racemic metazocine (Va) and phenazocine (Vb) with overall yields of 42% and 27%, respectively, is presented.