Evaluation of the Fouling Phenomenon During Membrane Clarification of Apple Juice Using Scraped Surface Membrane Unit

Introduction As a useful fruit for humans, apple (Malus domestica) is a good sourceof antioxidants, minerals, ascorbic acid, vitamins, polyphenols, fibers and other essential elements with medicinal properties. Improving the storage time of apple juice and maintaining the stability of extracts with high Brix value (during transportation and storage) and its marketability by removing the remaining water as well as reducing the turbidity, viscosity and brown color caused by colloidal suspended solids. Large (pectin, protopectin, pigments, polymeric carbohydrates, tannin, starch, cellulose, hemicellulose, fibers, etc.) is of great importance. Due to the presence of colloidal suspended solid particles and compounds that settle over time (mold, bacteria, plant cell fragments, pectin-tannin complex), apple juice must be clarified before concentration. Due to the high-energy consumption, time-consuming, degradation of thermo-sensitive components, and reduction of nutritional value in traditional methods, recently, the use of membrane concentration in food and beverage production holds great potential.. Despite all the benefits of membrane processes, one of the critical problems is permeate flux decline due to the concentration polarization and membrane fouling. In this study, an innovative mechanical motion was developed to remove the cake deposits on the membrane surface towards mitigating adverse effects of polarization and fouling.   Materials and Methods Membrane scraped surface module was designed and made with polyethylene material. The membrane was enclosed between the lower and upper parts of the module. These two parts are connected with screws and create a cylindrical part. Also, two caps are pressed axially to this cylindrical part by a metal frame to eliminate any unwanted leakage. The rotor shaft was coupled with an electric motor and the rotation of the output shaft was regulated by an inverter. A pump transferred the fresh fruit juice to the module through the inlet port and then it was divided into two output streams, permeate and retentate. The permeate was collected from the bottom of the module for further investigation and the retentate was returned to the juice tank. A polyethersulfone (PES) membrane with molecular weight cut-off (MWCO) of 4 kDa was used to clarify apple juice. Effects of the blade rotation speed (0, 600, 1400 and 2200 rpm), transmembrane pressure (TMP) (0.5, 1 and 1.5 bar), feed flow rate (FFR) (10, 15 and 20 ml/s) and the distance of the blade from the membrane surface (2 and 5 mm) on volumetric concentration factor (VCF) and fouling phenomenon were evaluated. Hermia model was used to study the main fouling mechanism and it was verified by scanning electron microscopy (SEM) images.   Results and Discussion  Results showed that rotating the blade with speed of 600 rpm at TMP of 0.5 bar, FFR of 10 ml/s and 2 mm distance from the membrane surface had the best performance in VCF and reducing fouling. The main mechanism of fouling was cake formation. Rotation of the blade decreases the intensity of cake formation and its thickness on the membrane surface and enhances the standard pore blocking. Also increasing the blade rotation speed changes the main fouling mechanism to the standard pore blocking due to the cake disintegration on the membrane surface and the penetration of fine particles into the membrane pores. As a result, the rotation of blade had a significant positive effect on increasing the VCF. On the other hand, the total resistance decreased with the rotation of the blade and by increasing the distance of blade from the membrane surface, the intensity of cake formation reduced. Also, the SEM images showed that in without blade rotation mode, the accumulation of cake particles on the membrane surface is thicker and denser than in with blade rotation mode. On the other hand, the low thickness of the cake layer formed on the membrane surface in the process of blade rotation is due to the turbulences resulting from the rotating blade. These observations confirm the results of the Hermia model in the previous sections.   Conclusion  In conclusion, the TMP 0.5 bar, FFR of 10 ml/s, blade rotation speed of 600 rpm with a distance of 2 mm from membrane surface were considered as the best conditions for ultrafiltration of apple juice using scraped-surface membrane unit

Unrealistic pessimism and obsessive‐compulsive symptoms during the COVID‐19 pandemic: two longitudinal studies

OBJECTIVE: Unrealistic pessimism (UP) is an aspect of overestimation of threat (OET) that has been associated with obsessive‐compulsive disorder/symptoms (OCD/OCS). During the COVID‐19 pandemic, UP may have played an important role in the course of OCD. To investigate the relationship, we conducted two longitudinal studies assuming that higher UP predicts an increase in OCS. METHOD: In Study 1, we investigated UP in the general population (N = 1,184) at the start of the pandemic asking about overall vulnerability to infection with SARS‐CoV‐2 and UP regarding infection and outcome of severe illness. Further, OCS status (OCS+/−) was assessed at the start of the pandemic and 3 months later. In Study 2, we investigated UP in individuals with OCD (N = 268) regarding the likelihood of getting infected, recovering, or dying from an infection with SARS‐CoV‐2 at the start of the pandemic and re‐assessed OCS 3 months later. RESULTS: In Study 1, UP was higher in the OCS+ compared to the OCS− group, and estimates of a higher overall vulnerability for an infection predicted a decrease in OCS over time. UP regarding severe illness predicted an increase in symptoms over time. In Study 2, UP was found for a recovery and death after an infection with SARS‐CoV‐2, but not for infection itself. CONCLUSIONS: Exaggeration of one’s personal vulnerability rather than OET per se seems pivotal in OCD, with UP being associated with OCD/OCS+ as well as a more negative course of symptomatology over the pandemic in a nonclinical sample. PRACTITIONER POINTS: Unrealistic optimism, a bias common in healthy individuals, is thought to be a coping mechanism promoting well‐being in the face of danger or uncertainty. The current study extends findings that its inversion, unrealistic pessimism, may play an important role in obsessive‐compulsive disorder and may also be involved in the development of the disorder. This study highlights the importance that prevention programs during a pandemic should include targeting unrealistic pessimism

Is the rotation of the femural head a potential initiation for cutting out? A theoretical and experimental approach

We conclude the center-center position in the head of femur of any kind of lag screw or blade is to be achieved to minimize rotation of the femoral head and to prevent further mechanical complications

Introducing a novel music medicine for depression

ORCiD ID: Costas I. Karageorghis https://orcid.org/0000-0002-9368-0759; Steffen Moritz https://orcid.org/0000-0001-8601-0143; Isgard Ohls https://orcid.org/0000-0002-3329-3116; Veena Kumari https://orcid.org/0000-0002-9635-5505.Copyright © 2022 The Author(s). In this report, we present the first case of depression showing symptomatic improvement with the auditory training program, Music for the Mind 2, added to a standard treatment regimen. This commercially available program combines advanced psychoacoustic techniques with the improvisational art of Ostad Elahi (1895–1974) to encourage active listening by targeting early auditory information processing (EAIP) pathways. We introduced MFM2 as add-on therapy to standard treatment over a 3-week period and administered the listening regimen (minimum 20 min per day) to a young Caucasian male with a first episode of major depression. We assessed the impact of MFM2 on depressive symptomatology as well as coping mechanisms and mindfulness. The results showed that through targeting EAIP pathways and thus accessing higher-order cognitive functions (e.g., active listening), recovery from depressive symptoms can be accelerated. Further studies are needed to investigate the impact of auditory training, particularly MFM2, on clinical outcomes, brain structure, and function. Through this case report, we introduce an innovative, safe, and effective music medicine that can enhance the lives of people with depression

Too much of a good thing? Hand hygiene and the long-term course of contamination-related obsessive-compulsive symptoms

Increased hygiene behavior may be a factor in the development of contamination-related obsessive-compulsive symptoms (C-OCS). We aimed at investigating (1) the course of C-OCS over 1 year after the start of the COVID-19 pandemic and (2) the effects of changes in hand hygiene (i.e., duration and frequency of handwashing) and related distress regulation on the long-term course of C-OCS. In a longitudinal study, we assessed 1,220 individuals from the German general population at the start of the COVID-19 pandemic (t1), 3 months later (t2), and 12 months later (t3). Pre-pandemic data were available in a subsample from 2014 (n = 430). A decrease in C-OCS over the first year of the pandemic emerged with a small effect size. Thirty-six percent of the participants scored above the clinical cut-off score at t1, 31% at t2, and 27% at t3. In 2014, only 11% scored above the clinical cut-off score. Hierarchical regression showed that C-OCS at t1 was the strongest predictor of a long-term increase in C-OCS. With small effect sizes, change in the duration (not frequency) of handwashing from t1 to t2, as well as the distress-reducing effect of handwashing served as additional predictors. Implications for information on hand hygiene guidelines are discussed

Angiographic, hemodynamic and histological characterization of an arteriovenous fistula in rats

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Exploring Statelessness and Nationality in Iran

Iran has yet to be the subject of research looking into the gaps in the nationality law, which, could create and perpetuate statelessness. There were however, several pre-identified populations, some members of which are believed to be affected by statelessness, as well as gender discrimination in the nationality law - which causes and increases the risk of rendering children stateless. Therefore, based on this previous knowledge of potentially stateless populations, and the gaps/lack of certain safeguards against statelessness in the nationality law, this research provides a foundation for understanding nationality and statelessness in the country.

Preserved BK channel function in vasospastic myocytes from a dog model of subarachnoid hemorrhage

Cerebral vasospasm after subarachnoid hemorrhage (SAH) is due to contraction of smooth muscle cells in the cerebral arteries. The mechanism of this contraction, however, is not well understood. Smooth muscle contraction is regulated in part by membrane potential, which is determined by K conductance in smooth muscle. Voltage-gated (Kv) and large-conductance, Ca -activated K (BK) channels dominate arterial smooth muscle K conductance. Vasospastic smooth muscle cells are depolarized relative to normal cells, but whether this is due to altered Kv or BK channel function has not been determined. This study determined if BK channels are altered during vasospasm after SAH in dogs. We first characterized BK channels in basilar-artery smooth muscle using whole-cell patch clamping and single-channel recordings. Next, we compared BK channel function between normal and vasospastic cells. There were no significant differences between normal and vasospastic cells in BK current density, kinetics, Ca and voltage sensitivity, single-channel conductance or apparent Ca affinity. Basilar-artery myocytes had no, small- or intermediate-conductance, Ca -activated K channels. The lack of difference in BK channels between vasospastic and control cells suggests alteration(s) in other K channels or other ionic conductances may underlie the membrane depolarization and vasoconstriction observed during vasospasm after SAH. Copyright © 2008 S. Karger AG. + 2+ + + 2+ 2+ 2+ +