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The modelling of the ma ss transfer in pervaporation is one of the fundamental aspects to understand and therefore improve the process performance. This paper reviews the different models to analyse and predict the mass transport through the selective layer in pervaporation. It therefore provides an overview combined with some guidance about the different models proposed in the literature and the
For several membrane separation processes, hollow fibre modules are either an already established or a promising type of module. Based on the analogy between mass and heat transfer, an engineering approach is proposed to estimate the shell-side mass transfer coefficient for axial flow in hollow fibre modules with due allowance for the void fraction. The approach enables one to take the entrance ef
Pervaporation with hydrophobic membranes has been widely recognised as a possible process to recover organic compounds from wasterwater. Compared to vacuum pervaporation, on which many researchers have focused, sweep gas pervaporation has received little attention. The aim of this study was to analyse opportunities for integrating and optimising both process layouts for the treatment of wastewater
The dynamic properties of the actin cytoskeleton in smooth muscle cells play an important role in a number of cardiovascular disease states. The state of actin does not only mediate mechanical stability and contractile function but can also regulate gene expression via myocardin related transcription factors (MRTFs). These transcriptional co-activators regulate genes encoding contractile and cytos
Magnetkameran är en fantastisk medicinsk bildutrustning som kan producera detaljerade bilder av insidan av kroppen. Förutom bilder av vävnaden och dess struktur så kan magnetkameran också användas till att mäta olika egenskaper hos vävnaden. Om en vävnadsegenskap mäts i varje bildpixel så kan den resulterande bilden (parameterkartan) visas och användas för medicinsk bedömning, vilket kallas för kvThe magnetic resonance imaging (MRI) scanner is a remarkable medical imaging device, capable of producing detailed images of the inside of the body. In addition to imaging internal tissue structures, the scanner can also be used to measure various properties of the tissue. If a tissue property is measured in every image pixel, the resulting property image (the parameter map) can be displayed and u
Males and females differ in both parasite load and the strength of immune responses and these effects have been verified in humans and other vertebrates. Sex hormones act as important modulators of immune responses; the male sex hormone testosterone is generally immunosuppressive while the female sex hormone estrogen tends to be immunoenhancing. Different sets of T-helper cells (Th) have important
Bacterial growth after freezing/thawing was studied in two soils with a history of annual freezing/thawing events. Soil samples were frozen for 1 week at −3 °C or −18 °C, thawed at +4 °C, and respiration and bacterial growth (estimated using leucine incorporation) were compared with reference soils kept at +4 °C. There were no major differences between soils. A respiration pulse, peaking within 9
Despite the efforts to reduce its water consumption, the food industry still requires large amounts of water. Membrane processes have established themselves in the food industry at the beginning of the water loop for preparation of the intake water and at the end water loop for recovery and final treatment of the water. The focus of this paper is on two application studies related to water recover
Increasing oil prices and growing environmental concerns in recent years have driven the development of renewable biofuels. Until now, most of the bioethanol production concepts are based on sugar and starch crops as feedstock, while research on second generation of bioethanol concepts is investigating the use of cellulosic biomass such as straw, wood, etc. as feedstock. The first part of the pape
The ultrafiltration (UF) with diafiltration is the state-of-the-art process in the bulk pharmaceutical industry to separate solutions containing high and low molecular weight solutes. By applying UF with diafiltration, a feed stream can be separated into a concentrate with a high concentration of high molecular weight solutes and a permeate, which is nearly 100% free of high molecular weight solut
The focus of this paper is on the design of pervaporation units for wastewater treatment taking into account technical, economic, and environmental aspects. Two different sized industrial wastewater streams of water-chloroform, and of water-methyl-isobutylketone (MIBK) are considered. Based on a wastewater stream of 1,500 kg/d, a semi-batch process combining pervaporation with a decanter recycle l
The use of diafiltration is now the state-of-the-art in the food and beverage, biotech and pharmaceutical industry. In this paper, the advantages and disadvantages of the most common process modes of diafiltration, batch and continuous, are discussed. Further, the new concept of counter-current diafiltration, which leads to a significant reduction of diafiltration liquid consumption, is introduced
In hydrophobic pervaporation, the evaluation and prediction of coupling effects in multicomponent systems is one of the key requirements to improve its applicability in the biotechnology and food industry. The focus of this study is first on binary aqueous systems with methanol, ethanol, acetone, 1-propanol, 2-propanol 1,3-dioxane, and 1,4-dioxane, and then on ternary aqueous systems with 1-propan
The different processes used for producing carrageenan, which is a sulfated polysaccharide consisting of complex mixture of sodium, potassium, magnesium, and calcium, are discussed. The sources of carrageenan are several genera and species of red algae. The traditional production process involves extraction with water and mechanical devices to remove most extraneous products. A new generation of s
Background: Porous metal augments have been used successfully for management of large acetabular defects during revision hip arthroplasty. The purpose of this study was to retrospectively review and compare the clinical and radiographic outcomes of porous metal augments in cemented and uncemented acetabular revisions, all performed at the same institution. Methods: Using our institutional clinical
Hydrophobic pervaporation is rarely considered in the biotech industry despite several potential advantages and some applications. This is related to fact that the majority of studies have been with binary feed systems, while real feed mixtures are often multi-component and might contain impermeable components, such as salts and sugars. In order to successfully optimise hydrophobic pervaporation,
