Process monitoring and visualization solutions for hot-melt extrusion : a review

Objectives: Hot-melt extrusion (HME) is applied as a continuous pharmaceutical manufacturing process for the production of a variety of dosage forms and formulations. To ensure the continuity of this process, the quality of the extrudates must be assessed continuously during manufacturing. The objective of this review is to provide an overview and evaluation of the available process analytical techniques which can be applied in hot-melt extrusion. Key Findings: Pharmaceutical extruders are equipped with traditional (univariate) process monitoring tools, observing barrel and die temperatures, throughput, screw speed, torque, drive amperage, melt pressure and melt temperature. The relevance of several spectroscopic process analytical techniques for monitoring and control of pharmaceutical HME has been explored recently. Nevertheless, many other sensors visualizing HME and measuring diverse critical product and process parameters with potential use in pharmaceutical extrusion are available, and were thoroughly studied in polymer extrusion. The implementation of process analytical tools in HME serves two purposes: (1) improving process understanding by monitoring and visualizing the material behaviour and (2) monitoring and analysing critical product and process parameters for process control, allowing to maintain a desired process state and guaranteeing the quality of the end product. Summary: This review is the first to provide an evaluation of the process analytical tools applied for pharmaceutical HME monitoring and control, and discusses techniques that have been used in polymer extrusion having potential for monitoring and control of pharmaceutical HME

Energy Information Systems: From the Basement to the Boardroom

A significant buildings energy reduction opportunity exists in the office sector, given that this market segment typically is an early adopter of new technology. There is a rising trend towards smart and connected offices through the internet of things (IoT) that provides new opportunities for operational efficiency and environmental sustainability practices. Leading commercial real estate companies have begun to shift from individual building automation systems (BAS) to partially integrated and automated systems such as energy information systems (EIS). In both the United States and India, organizations are seeking operational excellence, enhanced tenant relationships, and topline growth. Hence it is imperative to engage the executives with decision-making power, by tapping into their interest in sustainability, corporate social responsibility, and innovation. This expansion of interest can enable data-driven decisions, strong energy investments, and deeper energy benefits, and would drive innovation in this field. However, none of this would be possible without robust, consistent building energy information to provide visibility across all the levels of decision making, i.e. from the basement where the facilities staff take operational action to the boardroom where the executives make investment decisions. Price, security, and ease of use remain barriers to the adoption and pervasive use of promising EIS technologies in commercial office buildings. We believe that these barriers can be addressed through the development of ready, simplified, consistent, commercially available, low-cost EIS-in-a-box packages, that have a pre-defined set of hardware components and software features and functionality that are pertinent to a particular building sector. These simplified, sector-specific EIS packages can help to obviate the need for customization, and enhance ease of use, thereby enabling scale-up, in order to facilitate building energy savings. The EIS-in-a-box are adaptable in both U.S. and Indian office buildings, and potentially beyond these two countries

Development of Magnetostrictive Transducer Prototype for Blockage Detection on Molten Salt Pipes

In solar thermal power plants molten salt is often used to store and transport the energy that is collected during the day. The external pipe temperature is measured to activate an electric heating system if the temperature approaches the melting point. However, salt solidification cannot be completely excluded from the plant management. Once occurred, the location of a salt blockage is very complex due to the high temperature of the pipe. Therefore, when this problem arises, power plants have to stop production with the consequences in time and cost that this entails. Electro-magnetic acoustic transducers can be used as non-destructive testing systems for this application. A method for salt blockage detection is proposed that is applicable in straight sections of pipes by employing torsional guided waves that are generated with magnetostrictive transducers. The present paper deals with the transducer conception and the design of the power supply to activate it. Two alternatives are proposed and compared to determine the improvement in the amplitude/noise ratio. Finally, the experimental results show the performance of the equipment in a small prototype, thus validating the technique presented

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 159

This bibliography lists 257 reports, articles, and other documents introduced into the NASA scientific and technical information system in September 1976

Beating the reaction limits of biosensor sensitivity with dynamic tracking of single binding events

The clinical need for ultrasensitive molecular analysis has motivated the development of several endpoint-assay technologies capable of single-molecule readout. These endpoint assays are now primarily limited by the affinity and specificity of the molecular-recognition agents for the analyte of interest. In contrast, a kinetic assay with single-molecule readout could distinguish between low-abundance, high-affinity (specific analyte) and high-abundance, low-affinity (nonspecific background) binding by measuring the duration of individual binding events at equilibrium. Here, we describe such a kinetic assay, in which individual binding events are detected and monitored during sample incubation. This method uses plasmonic gold nanorods and interferometric reflectance imaging to detect thousands of individual binding events across a multiplex solid-phase sensor with a large area approaching that of leading bead-based endpoint-assay technologies. A dynamic tracking procedure is used to measure the duration of each event. From this, the total rates of binding and debinding as well as the distribution of binding-event durations are determined. We observe a limit of detection of 19 fM for a proof-of-concept synthetic DNA analyte in a 12-plex assay format.First author draf

An Alternative Perfusion Approach for the Intensification of Virus-Like Particle Production in HEK293 Cultures

Altres ajuts: Fundació la Caixa (LCF/BQ/ES17/11600003)Virus-like particles (VLPs) have gained interest over the last years as recombinant vaccine formats, as they generate a strong immune response and present storage and distribution advantages compared to conventional vaccines. Therefore, VLPs are being regarded as potential vaccine candidates for several diseases. One requirement for their further clinical testing is the development of scalable processes and production platforms for cell-based viral particles. In this work, the extended gene expression (EGE) method, which consists in consecutive media replacements combined with cell retransfections, was successfully optimized and transferred to a bioreactor operating in perfusion. A process optimization using design of experiments (DoE) was carried out to obtain optimal values for the time of retransfection, the cell specific perfusion rate (CSPR) and transfected DNA concentration, improving 86.7% the previously reported EGE protocol in HEK293. Moreover, it was successfully implemented at 1.5L bioreactor using an ATF as cell retention system achieving concentrations of 6.8·10 10 VLP/mL. VLP interaction with the ATF hollow fibers was studied via confocal microscopy, field emission scanning electron microscopy, and nanoparticle tracking analysis to design a bioprocess capable of separating unassembled Gag monomers and concentrate VLPs in one step

Advantages of building information modeling (bim) during the operational life

Building Information Modeling (BIM) technology is rapidly gaining traction in facility management and operations. This software aids in the effective management and exchange of building data, offering valuable benefits throughout construction stages, from planning to maintenance. This study delves into the factors affecting the operational performance of a BIM model and its paramount benefits during the digital design phase. Emphasis is placed on the merits of BIM during the operational phase, primarily using Autodesk Revit software. The research includes an analysis of engineering systems, particularly digital modeling of HVAC, water supply, and electrical systems. Drawing from BIM implementation experiences in Ukraine, the study reviewed significant contributions to digital model designs, examining BIM models across various infrastructure projects. A unique aspect of this research is the development of a digital BIM model using Autodesk Revit 2016, which uses advanced tools to spotlight the benefits of modeling throughout the design process

Doctor of Philosophy

dissertationThe modern age is filled with ever-advancing electronic devices. The contents of this dissertation continue the desire for faster, smaller, better electronics. Specifically, this dissertation addresses a field known as "spintronics", electronic devices based on an electron's spin, not just its charge. The field of spintronics originated in 1990 when Datta and Das first proposed a "spin transistor" that would function by passing a spin polarized current from a magnetic electrode into a semiconductor channel. The spins in the channel could then be manipulated by applying an electrical voltage across the gate of the device. However, it has since been found that a great amount of scattering occurs at the ferromagnet/semiconductor interface due to the large impedance mismatch that exists between the two materials. Because of this, there were three updated versions of the spintronic transistor that were proposed to improve spin injection: one that used a ferromagnetic semiconductor electrode, one that added a tunnel barrier between the ferromagnet and semiconductor, and one that utilized a ferromagnetic tunnel barrier which would act like a spin filter. It was next proposed that it may be possible to achieve a "pure spin current", or a spin current with no concurrent electric current (i.e., no net flow of electrons). One such method that was discovered is the spin Seebeck effect, which was discovered in 2008 by Uchida et al., in which a thermal gradient in a magnetic material generates a spin current which can be injected into adjacent material as a pure spin current. The first section of this dissertation addresses this spin Seebeck effect (SSE). The goal was to create such a device that both performs better than previously reported devices and is capable of operating without the aid of an external magnetic field. We were successful in this endeavor. The trick to achieving both of these goals was found to be in the roughness of the magnetic layer. A rougher magnetic layer led to both a larger coercive field and a stronger SSE signal. The second section of this dissertation is focused on a potential application of the SSE as a nuclear radiation detection tool. Specifically, the ability for a SSE device to detect gamma radiation was tested and found to be very sensitive with a sensitivity of ~20 nanocurie being reported. Furthermore, the SSE device was sensitive to gamma radiation even at room temperature, an advantage over current gamma radiation sensors which require cryogenic temperatures to function. The third section of this dissertation is focused on further improving future spintronic devices through the use of two-dimensional (2D) materials, as 2D materials have a wide variety of properties which are excellently suited to spintronics applications. Molybdenum disulfide (MoS2), a popular semiconducting 2D material, was synthesized using a pulsed-laser deposition technique. We were able to grow a single monolayer of MoS2 using this technique, one of the first groups in the world to report such a feat. The works presented herein show the potential of the spin Seebeck effect to function not only as a pure spin current injector, but also as a gamma radiation detector. Furthermore, the research conducted on MoS2 showed the possibility of large-scale, monolayer growth of 2D materials. Subsequent testing on these films has begun on finding the spin transport and detection properties of MoS2