Probabilistic Design space determination in pharmaceutical product development: A Bayesian/latent variable approach

To find the design space (DS) of a pharmaceutical process, quantification of the “assurance of quality” for the product under development is required. In this study, latent‐variable modeling is combined with multivariate Bayesian regression to identify a subset of input combinations (process operating conditions and raw materials properties) within which the DS of the product will lie at a probability equal to, or greater than, an assigned threshold. Partial least‐squares regression is used to obtain a linear transformation between the original multidimensional input space and a low‐dimensional latent space. The input domain is then discretized on its lower dimensional representation and a Bayesian posterior predictive approach is used to quantify the probability that the critical quality attributes of the product will meet their specifications for each discretization point. The methodology is tested on two case studies taken from the literature, one of which involving experimental data. The ability of the proposed approach to obtain a probabilistic identification of the DS, while simultaneously reducing the computational burden for the discretization of the input domain and providing a simple graphical representation of the DS, is shown. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2438–2449, 2018     

Role of Ni<Superscript>2+</Superscript> Ions in Magnetite Nano-particles Synthesized by Co-precipitation Method

In the present work, nickel-doped iron oxide (Ni_xFe_3?x O ₄) nanoparticles with different concentration of nickel (x = 0, 0.05, 0.1, and 0.15) have been prepared by co-precipitation method. These prepared nanoparticles have been characterized by using x-ray diffractometer, thermo gravimetric analysis and differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, vibrating sample magnetometer, and UV-Visible spectroscopy to study their structural, thermal, morphological, magnetic, and optical properties, respectively. The x-ray diffraction confirms the formation of single-phase inverse spinel cubic structure of NiFe₃ O ₄ nanoparticles. Crystallite size has been estimated by the full width at half maximum of the most intense x-ray diffraction peak where vibrational and stretching modes of metal-oxygen bonds in 872 cm are shown in Fourier transform infrared spectra which confirms the formation of nanoparticles. The thermal analysis revealed that the transition temperature and stability increases with increasing Ni concentration. The surface morphology indicated that the particles are spherical in shape with some agglomeration. The magnetic measurement revealed that the coercivity and anisotropy increases with nickel doping in magnetite nanoparticles. The optical analysis revealed that direct and indirect both types of band gap increases when the particle size decreases because the absorption spectra shift toward smaller wavelength. The blue shift confirms the formation of nanoparticles.     

Nutritive value of canola (Brassica napus L.) as affected by plant growth promoting rhizobacteria

Comparative evaluation of plant growth promoting rhizobacteria viz. Azospirillum brasilense, Azotobacter vinelandii Khsr1 and chemical fertilizers was made on growth, protein, and oil yield as well as quality of canola (Brassica napus L.) cv. Rainbow. The A. brasilense and A. vinelandii were applied as seed inoculation at 10⁶ cells/mL. The recommended doses of urea (150 kg/ha) and diamonium phosphate (180 kg/ha) were applied as sources of chemical fertilizers. First dose of chemical fertilizers was applied at the time of sowing while other three doses were applied at 45 days interval. The chemical fertilizers were highly effective in increasing leaf chlorophyll content, number of branches per plant, number of siliqua per branch, number of seeds per siliqua, and total seed yield. A. brasilense treatment increased the leaf and seed protein content (32 and 21%) as well as seed size as measured by % increase in 1000 seed weight. A. vinelandii treatment resulted in significant increase (4%) in seed oil contents but the glucosinolate and erucic acid (C22:1) contents of oil was decreased significantly. Maximum oleic acid (C18:1) content was found in seed oil of A. vinelandii treatment; whereas, significantly higher linolenic acid (C18:3) content was recorded in A. brasilense treatment. It is inferred from the present investigation that A. brasilense and A. vinelandii could be highly effective in improving yield and nutritive value of canola oil.     

Physicochemical studies of mild steel corrosion and atmospheric corrosivity mapping of Karachi: An important harbor city of modern Maritime Silk Route

This paper has reported physicochemical features of mild steel's corrosion products and provided atmospheric corrosivity maps of Karachi harbor city, drafted on the basis of spatial distribution of corrosion data from July 2018 to June 2019 at 10 different urban, industrial, and marine test sites. Exposure tests have been performed to study atmospheric corrosivity, corrosion products, and corrodants including chloride, sulfur dioxide, time of wetness (TOW), and corrosion rate as per ISO and ASTM standards. Scanning electron microscope, Fourier-transform infrared spectroscopy, and X-ray diffraction have corroborated the presence of lepidocrocite, goethite, magnetite, and quartz phases at almost all the test sites, with slight variations in their morphologies and quantities. The data analysis has revealed that TOW is a major detrimental factor to accelerate corrosion of mild steel at Karachi city. The corrosivity category of all urban and marine test sites is found in C₄–C₅ range, whereas for industrial test sites, it is found in C₃–C₅ range. Resultant corrosivity maps have shown that the prevailing atmosphere is significantly corrosive at Karachi harbor city. This study has furnished a novel product of atmospheric corrosivity map, which is the first-ever corrosivity map for Pakistan.     

Green synthesis of reactive dye for ink‐jet printing

Chloropyrimidine‐based reactive dyes are reported as well suited to textile printing; however, nucleophilic aromatic substitution of chloropyrimidines with amino‐containing chromophores is slow and often suffers from poor yields. In this study, a novel and simple method was developed for the synthesis of chloropyrimidine‐based reactive dye under microwave irradiation. In addition, the dye was also synthesised by conventional heating for comparison, which took both the reaction time and yield into account. The progress of the synthesis reactions concerned were monitored using capillary electrophoresis and the purity of the dye obtained was assessed by thin‐layer chromatography. The structure of the synthesised trichloropyrimidine dye was confirmed by Fourier Transform–infrared spectroscopy and elemental analysis. It was found that the reaction rate of the nucleophilic aromatic substitution carried out under microwave irradiation was 4‐fold faster than that carried out under conventional heating, although the enhancement in product yield was modest. These results suggest that microwave irradiation is an effective technique for the synthesis of chloropyrimidine‐based reactive dyes. The synthesised chloropyrimidine dye was formulated into an ink and applied onto a wool fabric by ink‐jet printing. The printed fabrics were steamed at 102°C for 5‐25 minutes at 5‐minute intervals. Good K/S and rate of dye fixation were obtained, both of which improved with increasing steaming time. The prints obtained exhibited reasonably good light and wash fastness properties.     

Durable and Recyclable Superhydrophobic Fabric and Mesh for Oil–Water Separation

The authors report durable and recyclable nanocomposite superhydrophobic coatings on two different substrates of fabric and mesh as prepared by titania nanoparticles and polydimethysiloxane (PDMS). The felted wool fabric and the steel mesh are initially coated with a thin layer of PDMS, which is followed by the deposition of nanocomposite coating of titania nanoparticles embedded in PDMS. The dual surface modification of two kinds of substrates generates highly hydrophobic surface character, which is retained after durability performance as measured in ultrasonication, sand, and emery paper abrasion tests. Oil–water separation experiments are performed using water mixtures with four oils, that is, n‐hexane, toluene, kerosene, and diesel to ensure the industrial applications of prepared composite materials. Moreover, nanocomposite coatings are tested for several cycles of oil–water separation in harsh conditions such as hot water, sodium chloride, and hydrochloric acid. The adopted approach improves the separation performance by inducing durability of the prepared nanocomposite coatings along with introducing recyclable character.     

Interdependence of piezoelectric coefficient and film thickness in LiTaO3 cantilevers

Electromechanical energy demands on homogenous thick films of piezoceramics with sufficiently large piezoelectric constant and reproducible performance. Single-phase LiTaO₃ films deposited by sol-gel processing have been fabricated as cantilevers to investigate the interdependence of dielectric and piezoelectric properties as a function of film thickness. Phase pure LiTaO₃ films with varying thickness in the range of 2.07-4.37 µm on stainless steel substrates were obtained after calcination of samples at 650°C. The relative permittivity of optimized spin-coated films peaked at 479.73 (1 kHz), whereas the piezoelectric coefficient (d₃₃ mode) determined by piezoresponse force microscopy was in the range of 21-24 pm/V. The effect of poling was studied through the butterfly and phase curves. A figure of merit (FOM) up to 3.29 (10⁻¹⁸ m²/V²) was determined for cantilever devices, which were able to generate a peak-to-peak voltage of 0.046-0.15 V using a 1 MΩ resistor as an impedance load at a fixed acceleration of 1.5 m/s². While the power density was in the range of ~4-20 × 10⁻⁹ W/m³, which increased with the increasing film thickness. The leakage current density decreased in the range of 4 × 10⁻⁵-6 × 10⁻⁷ A/m² in the same direction. As both ferroelectric and piezoelectric properties of LiTaO₃ films are dependent on film thickness, an optimal energy conversion efficiency was obtained for a thickness of ~3 µm. Furthermore, these devices were tested up to a temperature of 150°C for voltage generation. Given the need for lead-free piezoelectric materials for environmental applications, these LiTaO₃ cantilevers are very promising for vibrational energy harvester (VEH) applications especially due to their cost effectiveness, small size, stability at higher temperatures, and repeatable properties, which makes them suitable for MEMS devices for industrial applications.     

A (solvent-free) approach to metal-free photo-catalysts for methylene blue degradation

Iranian Polymer Journal - The hazardous industrial effluent, enriched in organic dyes, produces environmental alarms of being resistant to natural degradation processes. Therefore, the development...     

Retention and stability of bioactive compounds in functional peach beverage using pasteurization,microwave and ultrasound technologies

Food Science and Biotechnology - The peach functional beverages pasteurized for 10&nbsp;min at 90&nbsp;°C, microwaved for 1.5&nbsp;min at 850&nbsp;W of power and sonicated for...     

Capillary driven flow in wettability altered microchannel

The capillary driven flow of water inside a microchannel with altered wettabilities is experimentally investigated and modeled theoretically. The surfaces of the PDMS made microchannel are exposed to oxygen plasma, rendering the surfaces increasingly hydrophilic, which provides the driving force for the flow. The plasma treated surfaces are characterized using topography and phase imaging of AFM scanning, as well as nano‐indentation, to correlate the distinct structural changes to the hydrodynamic profiles of the advancing meniscus. The experimental results are further analyzed using a newly proposed slip velocity model. The aim is to obtain a qualitative relationship between the surface properties and the flow parameters, namely the advancing meniscus velocity and pressure drop inside the channel. The insights are of fundamental importance in diverse fields, such as enhanced oil recovery, microfluidic devices, cell separation, and pathology. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4616–4627, 2017