scholarly journals Recent Advancements of UF-Based Separation for Selective Enrichment of Proteins and Bioactive Peptides—A Review

2021 ◽  
Vol 11 (3) ◽  
pp. 1078
Author(s):  
Enny Ratnaningsih ◽  
Reynard Reynard ◽  
Khoiruddin Khoiruddin ◽  
I Gede Wenten ◽  
Ramaraj Boopathy
Keyword(s):  
Protein Separation ◽  
Building Blocks ◽  
Ultrasonic Waves ◽  
Operating Conditions ◽  
Selective Enrichment ◽  
Membrane Surfaces ◽  
Unique Protein ◽  
Pharmaceutical Industries ◽  
Uf Membranes ◽  
Separation Of Proteins

Proteins are one of the primary building blocks that have significant functional properties to be applied in food and pharmaceutical industries. Proteins could be beneficial in their concentrated products or isolates, of which membrane-based filtration methods such as ultrafiltration (UF) encompass application in broad spectra of protein sources. More importantly, selective enrichment by UF is of immense interest due to the presence of antinutrients that may dominate their perspicuous bioactivities. UF process is primarily obstructed by concentration polarization and fouling; in turn, a trade-off between productivity and selectivity emerges, especially when pure isolates are an ultimate goal. Several factors such as operating conditions and membrane equipment could leverage those pervasive contributions; therefore, UF protocols should be optimized for each unique protein mixture and mode of configuration. For instance, employing charged UF membranes or combining UF membranes with electrodialysis enables efficient separation of proteins with a similar molecular weight, which is hard to achieve by the conventional UF membrane. Meanwhile, some proposed strategies, such as utilizing ultrasonic waves, tuning operating conditions, and modifying membrane surfaces, can effectively mitigate fouling issues. A plethora of advancements in UF, from their membrane material modification to the arrangement of new configurations, contribute to the quest to actualize promising potentials of protein separation by UF, and they are reviewed in this paper.

scholarly journals Cold-Active β-Galactosidases: Insight into Cold Adaption Mechanisms and Biotechnological Exploitation

Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 43
Author(s):  
Marco Mangiagalli ◽  
Marina Lotti
Keyword(s):  
Low Temperature ◽  
Molecular Mechanisms ◽  
Building Blocks ◽  
Cold Active ◽  
Cold Adaption ◽  
Glycosyl Donor ◽  
Pharmaceutical Industries ◽  
Biotechnological Processes ◽  
Hydrolysis Of ◽  
Insight Into

β-galactosidases (EC 3.2.1.23) catalyze the hydrolysis of β-galactosidic bonds in oligosaccharides and, under certain conditions, transfer a sugar moiety from a glycosyl donor to an acceptor. Cold-active β-galactosidases are identified in microorganisms endemic to permanently low-temperature environments. While mesophilic β-galactosidases are broadly studied and employed for biotechnological purposes, the cold-active enzymes are still scarcely explored, although they may prove very useful in biotechnological processes at low temperature. This review covers several issues related to cold-active β-galactosidases, including their classification, structure and molecular mechanisms of cold adaptation. Moreover, their applications are discussed, focusing on the production of lactose-free dairy products as well as on the valorization of cheese whey and the synthesis of glycosyl building blocks for the food, cosmetic and pharmaceutical industries.

Piezoelectric Nanogenerators for Mechanical Energy Harvesting

2011 ◽  
Vol 2011 (1) ◽  
pp. 000367-000375
Author(s):  
Xudong Wang
Keyword(s):  
Energy Harvesting ◽  
Mechanical Energy ◽  
External Disturbance ◽  
Low Frequency ◽  
Life Time ◽  
Building Blocks ◽  
Metal Electrode ◽  
Ultrasonic Waves ◽  
Piezoelectric Potential ◽  
Piezoelectric Thin Film

Piezoelectric ZnO nanowires (NWs) have recently been demonstrated as a promising concept to harvest micro- and nano-scale mechanical energy from the surroundings. It is named nanogenerator. The operation principle relies on the bending of NWs by an external disturbance which creates piezoelectric potential along the deformed surfaces. The piezoelectric potential was predicted to be hundreds of milivolts per NW and the optimal power output per NW could reach a few nanowatts when it is under resonant oscillation. The first nanogenerator prototype was fabricated with vertically aligned ZnO NW arrays that were placed beneath a zigzag-shaped metal electrode with a small gap. In this design, all the NWs can be actuated simultaneously and continuously by ultrasonic waves, leading to the production of a continuous DC current. A textile fiber based nanogenerator has been developed for harvesting low-frequency vibration/friction energies. A piezoelectric thin film based nanogenerator was demonstrated to convert low-speed wind energy into electricity through the stimulated oscillation. These devices have the potential to fundamentally improve the mechanical energy harvesting capability with advanced nanostructure building blocks and compact designs, which might eventually lead to an effective power source for self-powered electronic systems with higher energy density, higher efficiency, longer life time, as well as lower cost.

scholarly journals Direct Synthesis of Oxynitride Nanowires through Atmospheric Pressure Chemical Vapor Deposition

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2507
Author(s):  
Babak Adeli ◽  
Fariborz Taghipour
Keyword(s):  
Solid Solution ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Wide Spectrum ◽  
Direct Synthesis ◽  
Chemical Vapor ◽  
Building Blocks ◽  
Operating Conditions ◽  
Wide Range ◽  
Pressure Chemical

Binary and ternary oxynitride solid alloys were studied extensively in the past decade due to their wide spectrum of applications, as well as their peculiar characteristics when compared to their bulk counterparts. Direct bottom-up synthesis of one-dimensional oxynitrides through solution-based routes cannot be realized because nitridation strategies are limited to high-temperature solid-state ammonolysis. Further, the facile fabrication of oxynitride thin films through vapor phase strategies has remained extremely challenging due to the low vapor pressure of gaseous building blocks at atmospheric pressure. Here, we present a direct and scalable catalytic vapor–liquid–solid epitaxy (VLSE) route for the fabrication of oxynitride solid solution nanowires from their oxide precursors through enhancing the local mass transfer flux of vapor deposition. For the model oxynitride material, we investigated the fabrication of gallium nitride and zinc oxide oxynitride solid solution (GaN:ZnO) thin film. GaN:ZnO nanowires were synthesized directly at atmospheric pressure, unlike the methods reported in the literature, which involved multiple-step processing and/or vacuum operating conditions. Moreover, the dimensions (i.e., diameters and length) of the synthesized nanowires were tailored within a wide range.

Membrane Distillation Desalination System With Gap Circulation and Cooling Using a Built-in Heat Exchanger

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Atia E. Khalifa
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Specific Energy Consumption ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Water Desalination ◽  
Module Design ◽  
Membrane Surfaces ◽  
Best Value ◽  
Feed Temperature

Abstract A comprehensive experimental investigation is conducted to evaluate the performance of a new flux-enhanced compact water gap membrane distillation (WGMD) module design with gap circulation and cooling for water desalination. The new design uses a separate circulation loop to circulate the gap water, and a built-in heat exchanger coil implanted inside the coolant stream channel for cooling the circulated gap water. The WGMD modules with circulation and with circulation and cooling are compared with conventional WGMD without circulation. Variations of distillate flux, temperatures, and energy consumption are presented at different design operating conditions. Circulation and cooling of the gap water greatly enhance the output flux due to gap water motion and increase the temperature difference between membrane surfaces. However, the enhancement in flux was achieved at the expense of energy consumption. Circulation and cooling of gap water are more effective with bigger gap widths. Feed flowrate showed significant effects with gap water circulation and cooling. The electrical specific energy consumption (SEC) showed the best value of 7.9 and 8.8 kWh/m3 at a feed temperature of 70 °C for both conventional WGMD and WGMD with circulation modules, while the best value of SEC for the WGMD module with gap circulation and cooling was 9.4 kWh/m3 at a feed temperature of 80 °C.

scholarly journals Enhanced Fouling Resistance and Antimicrobial Property of Ultrafiltration Membranes Via Polyelectrolyte-Assisted Silver Phosphate Nanoparticle Immobilization

Membranes ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 293
Author(s):  
Kunal Olimattel ◽  
Jared Church ◽  
Woo Hyoung Lee ◽  
Karin Y. Chumbimuni-Torres ◽  
Lei Zhai ◽  
...  
Keyword(s):  
Membrane Surface ◽  
Antimicrobial Property ◽  
Layer By Layer ◽  
Permeate Flux ◽  
Fouling Resistance ◽  
Silver Phosphate ◽  
Membrane Surfaces ◽  
Polyallylamine Hydrochloride ◽  
Assembly Technique ◽  
Uf Membranes

Ultrafiltration (UF) is a low-pressure membrane that yields higher permeate flux and saves significant operating costs compared to high-pressure membranes; however, studies addressing the combined improvement of anti-organic and biofouling properties of UF membranes are lacking. This study investigated the fouling resistance and antimicrobial property of a UF membrane via silver phosphate nanoparticle (AgPNP) embedded polyelectrolyte (PE) functionalization. Negatively charged polyacrylic acid (PAA) and positively charged polyallylamine hydrochloride (PAH) were deposited on the membrane using a fluidic layer-by-layer assembly technique. AgPNPs were immobilized within the crosslinked “bilayers” (BL) of PAH/PAA. The effectiveness of AgPNP immobilization was confirmed by microprofile measurements on membrane surfaces using a solid contact Ag micro-ion-selective electrode. Upon stable and uniform BL formation on the membrane surface, the permeate flux was governed by a combined effect of PAH/PAA-derived hydrophilicity and surface/pore coverage by the BLs “tightening” of the membrane. When fouled by a model organic foulant (humic acid), the functionalized membrane exhibited a lower flux decline and a greater flux recovery due to the electrostatic repulsion imparted by PAA when compared to the unmodified membrane. The functionalization rendered antimicrobial property, as indicated by fewer attachments of bacteria that initiate the formation of biofilms leading to biofouling.

Microfluidic Valve Arrays in Thermoplastic Devices

2012 ◽  
Author(s):  
Z. Hugh Fan ◽  
Pan Gu ◽  
Shancy Augustine ◽  
Ke Liu ◽  
Harvy Freitag ◽  
...  
Keyword(s):  
Protein Separation ◽  
Low Cost ◽  
Building Blocks ◽  
Elastic Membrane ◽  
Two Dimensional ◽  
Thermal Actuation ◽  
Thermally Actuated ◽  
Separation Media ◽  
Orthogonal Channels ◽  
Cyclic Olefin Copolymers

Thermoplastics have been increasingly employed for microfluidic devices due to their manufacturability, low cost, and biocompatibility. A microfluidic device consists of a number of necessary building blocks, including microvalves that are often used for flow regulation. The state-of-the-art of the microfluidic valve technology is polydimethylsiloxane (PDMS)-based elastic membrane valve. This paper is to report the integration of the elastomer valve into a thermoplastic device. The valves were designed for a two-dimensional protein separation device, which was fabricated from cyclic olefin copolymers (COC). To realize the goal of integrating the elastomer-based valves in the device, the key challenge is to achieve strong bonding between COC and PDMS so that the device will not delaminate when a pressure is built up after the valves are closed. Microvalve arrays were fabricated in a COC/PDMS/COC device to facilitate the introduction of two types of separation media, without cross-contamination, into orthogonal channels in order to achieve two-dimensional separation. In addition, we studied thermal actuation in the microvalve, as an alternative to pneumatic actuation in the conventional PDMS-based elastomer valve. The thermally actuated valves can be self-contained, requiring less-bulky external accessories than pneumatically actuated valves.

scholarly journals Analysis of particle dynamics in a pin mill by Discrete Element Method

2021 ◽  
Vol 249 ◽  
pp. 07010
Author(s):  
Wei Pin Goh ◽  
Mojtaba Ghadiri
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Discrete Element Method ◽  
Discrete Element ◽  
Particle Dynamics ◽  
Operating Conditions ◽  
Impact Testing ◽  
Process Conditions ◽  
Pharmaceutical Industries ◽  
Element Method

Milling is an important process for tailoring the particle size distribution for enhanced attributes, such as dissolution, content uniformity, tableting, etc., especially for active pharmaceutical ingredients and excipients in pharmaceutical industries. Milling performance of particulate solids depends on the equipment operating conditions (geometry, process conditions and input energy etc.) as well as material properties (particle size, shape, and mechanical properties, such as Young’s modulus, hardness and fracture toughness). In this paper the particle dynamics in a pin mill is analysed using Discrete Element Method (DEM), combined with a novel approach for assessing particle breakability by single particle impact testing. A sensitivity analysis is carried out addressing the effect of the milling conditions (rotational speed and feed particle flow rate), accounting for feed mechanical properties on the breakage behaviour of the particles. Particle collision energy spectra are calculated and shown to have a distribution with the upper tail end being close to the maximum energy associated with the collision with the rings. Breakage is primarily due to collisions with the rings, except for large particles that are comparable in size with the gap between the rings, nipping is also a contributory breakage mechanism.

Analysis and Modeling of Liquid Holdup in Low Liquid Loading Two-Phase Flow Using Computational Fluid Dynamics and Experimental Data

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Miguel Ballesteros ◽  
Nicolás Ratkovich ◽  
Eduardo Pereyra
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Oil And Gas ◽  
Operating Conditions ◽  
Liquid Holdup ◽  
Liquid Loading ◽  
Two Phase ◽  
Acceptable Error ◽  
Pharmaceutical Industries

Abstract Low liquid loading flow occurs very commonly in the transport of any kind of wet gas, such as in the oil and gas, the food, and the pharmaceutical industries. However, most studies that analyze this type of flow do not cover actual industry fluids and operating conditions. This study focused then on modeling this type of flow in medium-sized (6-in [DN 150] and 10-in [DN 250]) pipes, using computational fluid dynamics (CFD) simulations. When comparing with experimental data from the University of Tulsa, the differences observed between experimental and CFD data for the liquid holdup and the pressure drop seemed to fall within acceptable error, around 20%. Additionally, different pipe sections from a Colombian gas pipeline were simulated with a natural gas-condensate mixture to analyze the effect of pipe inclination and operation variables on liquid holdup, in real industry conditions. It was noticed that downward pipe inclinations favored smooth stratified flow and decreased liquid holdup in an almost linear fashion, while upward inclinations generated unsteady wavy flows, or even a possible annular flow, and increased liquid holdup and liquid entrainment into the gas phase.

Improving the Operating Conditions of Gradient Ion-Exchange Simulated Moving Bed for Protein Separation

2013 ◽  
Vol 52 (15) ◽  
pp. 5407-5417 ◽  
Author(s):  
Xiaodan Wu ◽  
Harvey Arellano-Garcia ◽  
Weirong Hong ◽  
Günter Wozny
Keyword(s):  
Ion Exchange ◽  
Protein Separation ◽  
Operating Conditions ◽  
Simulated Moving Bed ◽  
Moving Bed

Solution Rheology of Saline and Polysaccharide Systems

2006 ◽  
Author(s):  
Ekmagage Don N. Almeida ◽  
Leela Rakesh ◽  
Stanley Hirschi ◽  
Anja Mueller
Keyword(s):  
Rheological Properties ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Water Soluble ◽  
Effluent Treatment ◽  
High Concentration ◽  
Concentrated Suspension ◽  
Cross Model ◽  
Low Concentrations ◽  
Pharmaceutical Industries

The problem of the characterization of the solution properties of water soluble polymers is long-standing. These polymers tend to form aggregated supramolecular gels that are resistant to molecular dispersion. These materials are being widely used in a variety of industrial applications. Their principle functions are as rheological modifiers, where they thicken or gel solutions in products such as hair-care, detergents, air fresheners and foods; as flocculants for particle separation as applied to water clarification, sewage, and effluent treatment, and as stabilizers to control the properties of concentrated suspension and emulsions, for example in paints, pesticides, dyes, and pharmaceutical industries. Therefore it is important to understand their rheological properties under various operating conditions such as stress, strain, temperature etc, which will induce gelation. The rheological properties of starch gels of high concentration (up to 86% starch) have been investigated before [1]. In this paper we have investigated experimentally the shear viscosity and viscoelasticity properties of saline and polysaccharide suspensions at various low concentrations and pH at different temperatures using controlled stress and strain rheometers (Vilastic-3 and AR 2000). The data were then fitted with the power law and Cross model for low and higher concentrations respectively. The present results show that the viscosity/elasticity does not significantly change for low concentrations at different pH values. The maximum viscosity/elasticity was obtained around pH 5-7.4 at higher concentrations.

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