AUTHOREA
Log in Sign Up Browse Preprints
LOG IN SIGN UP

Preprints

Explore 23,813 preprints on the Authorea Preprint Repository

A preprint on Authorea can be a complete scientific manuscript submitted to a journal, an essay, a whitepaper, or a blog post. Preprints on Authorea can contain datasets, code, figures, interactive visualizations and computational notebooks.
Read more about preprints.

Myxoma detected by intracardiac echocardiography during pulmonary vein isolation
Tsukasa Oshima
Yu Shimizu

Tsukasa Oshima

and 6 more

August 09, 2022
A 61-year-old woman with a low thromboembolic risk was scheduled to undergo pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation. Transthoracic echocardiography showed no cardiac structural abnormality. Intracardiac echocardiography (ICE) identified a small left atrium mass attached to the atrial septum and the procedure was stopped before the transseptal puncture; the surgically resected tumor was cardiac myxoma. ICE is a reliable imaging modality to exclude left atrial thrombus. However, unusual and unexpected cardiac structures also prevent performing PVI, which pre-procedural transesophageal echocardiography could identify. Imaging options should be further discussed to improve patient care and safety.
A surgical algorithm for the management of retrosternal goiters
Tsu-Hui (Hubert) Low
George Petrides

Tsu-Hui (Hubert) Low

and 6 more

August 09, 2022
Key points: - The heterogeneity of retrosternal goiter size and location, nearby anatomical structures, and evolving surgical techniques means selecting the most appropriate individualised surgical approach remains challenging. - Although most retrosternal goiters can be removed transcervically, a small proportion of patients fulfill anatomical and radiological criteria for concurrent extracervical approaches based on decades of experience at the London Health Sciences Centre. - Anterior goiters above the level of the pericardium were resected using cervical thyroidectomy with either mediastinoscopic-assisted delivery or cervical thyroidectomy with video- assisted thyroidectomy (VATS) - Anterior goiters extending beyond the pericardium require median sternotomy to facilitate sufficient vascular control and exposure. - Posteriorly extending goiters can be managed using trans-thoracic approaches including lateral thoracotomy or VATS.
Surface vascular and epithelial anatomy of the vocal folds in leukoplakia and cancer
Pavlos Pavlidis
Vasilios Tseriotis

Pavlos Pavlidis

and 4 more

August 09, 2022
Objective: To investigate the features of the superficial mucosa and microvascular network of the vocal cords in patients with suspected laryngeal cancer using contact endoscopy (CE). Design: A retrospective review of patients with leukoplakia and cancer of vocal cords. Main outcome measure: Fourty-two patients (mean age = 57.2 ±7.6 years), were prospectively evaluated. Eighteen had malignant lesions and 24 had leukoplakia, proven on histologic exam. Eight cancer patients and 8 patients with leukoplakia had bilateral lesions. Therefore, a total of 58 lesions (26 malignant and 32 non-malignant) was found. Contact-endoscopic imaging findings were classified into five types (I to V) based on the features of the mucosal intraepithelial capillary loops. Results: The CE-based intraepithelial papillary capillary loop classification was strongly correlated with the histological findings. Smoking habits didn’t significantly differ between patients with unilateral and bilateral lesions. Conclusions: CE imaging of the vocal cord mucosal capillaries may be useful in the early detection of laryngeal cancer and precancerous lesions.
Impact of long-term nasal airflow deprivation on sinonasal structures and chronic rhi...
Marn Joon Park
Mi Rye Bae

Marn Joon Park

and 5 more

August 09, 2022
Abstract Objectives: Total laryngectomy (TL) patients are good models in which to evaluate the effects of nasal airflow cessation on the sinonasal tract. Here, we evaluated changes in sinonasal structures and association with chronic rhinosinusitis (CRS), in the computed tomography (CT) images three-year post-TL. Design: Retrospective medical chart review. Setting: Tertiary referral medical center, teaching hospital setting. Participants: Data from patients that underwent TL from 2005–2017 were reviewed retrospectively. Patients with a final follow-up CT taken less than 3 years after TL, tracheo-esophageal puncture, inadequate CT image, or history of sinonasal surgery were excluded. The control group included partial laryngectomy or hypopharyngectomy patients. Altogether, 45 TL patients and 38 controls were selected. Main outcome measurements: The volume of all four paranasal sinuses, inferior turbinate mucosal volume (ITMV), maxillary sinus natural ostium (MSNO) mucosal width, and Lund-Mackay scores (LMS) were measured on preoperative and postoperative CT scans. Results: The mean duration between surgery and the final CT scan was 6.3±2.4 and 5.5±2.3 years for the TL and control groups, respectively. Neither group showed significant changes in four paranasal sinuses volume or MSNO mucosa width. The ITMV decreased significantly, from 4.6±1.3ml to 2.8±1.1ml (p<0.001), in the TL group, whereas the control group showed no significant changes. Postoperative LMS changes in both groups were insignificant. The number of patients with LMS aggravation or alleviation was the same in both groups, regardless of preoperative CRS. Conclusions: Paranasal sinus structures and CRS are not affected significantly by nasal airflow cessation; however, the inferior turbinate mucosa is affected by long-term discontinuation of nasal airflow.
Translation into Spanish and validation of the Tinnitus Functional Index.
Maria Montserrat Soriano-Reixach
Jorge Rey Martinez

Maria Montserrat Soriano-Reixach

and 4 more

August 09, 2022
Objective: The objectives of this study were to translate into Spanish, cross-culturally adapt and validate the TFI. Materials and Methods: The TFI questionnaire translated into Spanish (Sp-TFI) and cross-culturally adapted following the published guidelines on cross-cultural adaptation of health questionnaires was evaluated using two indicators. Its internal consistency was assessed with Cronbach’s α considering the Tinnitus Handicap Inventory (THI) as the gold standard. Further, its test-retest reliability was assessed with intraclass correlation coefficients (ICCs). ICCs were also calculated for the THI and visual analogue scales (VAS) for tinnitus tested and retested in all participants. Results: The mean age of the 18 participants was 45.77 (SD: 11.87) years; 12 were female (66.67 %) and 6 were male (33.33%). Half of the participants experienced tinnitus in their left ear and half in their right. The mean pure-tone average (PTA) in the affected ear was 29.34 (SD: 8.08) dB-HL. Regarding internal consistency and reliability of the Sp-TFI respectively, Cronbach’s α was 0.83 and the ICC type (2,1) was 1 (CI: 0.99–1). Among the variables studied, we found the following independent predictors had statistically significant effects on THI score: sex (p < 0.01), PTA (p = 0.03), overall Sp-TFI score (p = 0.02) and Sp-TFI SL, R and A subscale scores (p = 0.03, p = 0.03, and p < 0.01, respectively). Conclusion: Based on the internal consistency and reliability results obtained in this study, the cross-culturally adapted Spanish version of the TFI (Sp-TFI) has been validated for use in Spain.
Long-term functional swallowing and speech outcomes after transoral robotic surgery f...
Yong Bae Ji
Hae Won  Choi

Yong Bae Ji

and 6 more

August 09, 2022
Objective: Transoral robotic surgery (TORS) for oropharyngeal cancer was introduced to ensure better functional preservation with less morbidity. However, long-term functional outcomes, especially speech and swallowing outcomes, have not been thoroughly investigated. This study aimed to evaluate the long-term functional swallowing and speech outcomes after transoral robotic surgery for oropharyngeal cancer. Methods We studied 41 patients with oropharyngeal squamous cell carcinoma who underwent TORS between January 2010 and December 2018. Tongue mobility, maximal phonation time, articulation, verbal diadochokinesis, reading speed, and modified barium swallowing tests were performed between two and three years after TORS to analyze the long-term functional speech and swallowing outcomes. Results: The mean patient age was 57.7 ± 9.9 years, and the male to female ratio was 34:7. The most common subsite was the palatine tonsil (73.2%), followed by the base of tongue (22.0%). Forty patients (97.6%) underwent concomitant neck dissection, and 36 patients (87.8%) received adjuvant radiation or chemoradiation therapy. Tongue mobility, maximum phonation time, articulation, verbal diadochokinesis, and reading speed were not different from those of the normal population. Modified barium swallowing outcomes were acceptable in most patients; however, one patient (2.4%) was dependent on a percutaneous endoscopic gastrostomy tube. None of the patients required a permanent tracheostomy. Conclusions: Long-term speech and swallowing functions after TORS were acceptable in most patients with oropharyngeal cancer. TORS is an excellent treatment modality for oropharyngeal cancer in terms of functional outcomes.
Using a combination of conservative and enucleating to treat a large dentigerous cyst...
fahad khan
Brain Castling

fahad khan

and 1 more

August 09, 2022
Dentigerous cysts are the second most common type of odontogenic cysts. We performed a combination of conservative treatment and enucleation to prevent fracture and preserve vital structures in a two-staged approach
Lumbar Puncture as a Cause of Tension Pneumocephalus, Pneumorrachis, and Sacral Menin...
FARID AASSOUANI
Zaid Ennacery

FARID AASSOUANI

and 11 more

August 09, 2022
Although it was first described over 100 years ago,lumbar puncture is still an important diagnostic tool for a variety of infectious and noninfectious neurologic conditions.With the widespread use of this common and relatively safe performed medical procedure, minor and major complications can occur even when standard infection control measure
Variations in body shape between two sympatric haplochromine species: Implications fo...
Philippe Munyandamutsa
Wilson Jere

Philippe Munyandamutsa

and 3 more

August 09, 2022
Patterns of intra- and interspecific variation based on environmental conditions in which populations live may reflect adaptive responses to their habitat. This is particularly relevant in a lake habitat where closely related species occur sympatrically. This study was aimed at determining consistency in morphological traits in head and body shapes in two haplochromine species (Haplochromis insidiae and Haplochromis kamiranzovu) in littoral and/ pelagic zones and to estimate the extent to which the habitats affect variations between the species. Specimens of both species were taken from littoral and pelagic zones, in the northern and southern parts of Lake Kivu. Morphometrics and landmark-characteristics were recorded and compared within and between habitats. The results showed that differences were found among the two species, among the two zones and for both. The most prominent difference was in the head; including the relative size of the jaws, head length and position of the pectoral fin insertion. Variation in head morphology is normally related to feeding. Changes in body shape can be linked to differences in environment and food availability between the two habitats which could have enabled the species to co-exist. This capacity is important in lakes like Kivu which have low habitat diversity compared to other African Great lakes like Malawi, Tanganyika and Victoria and provide some explanation in the differences in the number of haplochromine species in these lakes. The genetic basis of these phenotypic changes should be examined in future research.
Could Premature Ventricular Contractions Lead to Atrial Remodeling?
Kemal Emrecan Parsova
Nursen keles

Kemal Emrecan Parsova

and 5 more

August 09, 2022
Background Premature ventricular contraction (PVC) is a frequent kind of arrhythmia that affects around %1 of the general population. While PVC most frequently impairs ventricular function in structurally normal heart, retrograde ventriculo-atrial conduction can occur in people with PVC. These retrograde atrial activations may mimic pulmonary vein-derived atrial ectopies. As a result, PVC may raise the risk of AF by retrograde ventriculo-atrial conduction. The Four-Dimensional Automated Left Atrial Quantification (4D Auto LAQ) tool is a left atrial analytical approach that utilizes three-dimensional volume data to quantify the volume, as well as LA longitudinal and circumferential strains. The purpose of this study was to determine if clinical diagnosis of PVC is connected with abnormal LA function as determined by LA strain evaluation utilizing a 4D Auto LAQ compared to the healthy population. Methods The 58 patients with frequent PVCs and 53 healthy volunteers as a control group were enrolled in the study. Imaging was performed using the GE Vivid E95 echocardiography equipment (GE Healthcare; Vingmed Ultrasound, Horten, Norway) equipped with an M5S probe (frequency range: 1.5–4.6 MHz) and a 4V probe (frequency range: 1.5–4.0 MHz). Images were imported into and were selected for analysis using the EchoPAC203 software (GE Healthcare). The analysis mode was selected, followed by the volume and 4D Auto LAQ submodes. Following that, the sample point was positioned in the center of the mitral orifice in each of the three planes. The review function was used to acquire the LA parameters measured by 4D Auto LAQ, including volume and strain parameters. Results The maximum left atrial volume (LAVmax) and minimal left atrial volume (LAVmin) were signifcantly higher in the patient group (38.91 ± 9.72 vs. 46.31 ± 10.22, 17.75 ± 4.52 vs. 23.10 ± 7.13 respectively, all p values <0,001). On the other hand left atrial reservoir longitudinal strain (LASr), conduit longitudinal strain (LAScd), contraction longitudinal strain (LASct), reservoir circumferential strain (LASr-c), conduit circumferential strain (LAScd-c), and contraction circumferential strain (LASct-c) were signifcantly lower in patient group (26.64 ± 5.64 vs.19.16 ± 4.58, -19.53 ± 3.72vs.-11.28 ± 3.47, -10.34 ± 1.56 vs.-4.59 ± 1.49, 30.72 ± 4.04 vs.19.31 ± 2.60, -19.91 ± 1.78 vs. -13.38 ± 2.85,-15.89 ± 6.37vs.-9.24 ± 1.63 , respectively, all p values <0,001). Conclusions The present study found that premature ventricular complexes can lead to atrial remodeling as well as ventricular remodeling in patients with PVC and 4D LAQ technology can quantitatively examine left atrial function and determine these alterations early.
Acute ST-Elevation Myocardial Infarction (STEMI) in Patient with Severe Uncontrolled...
Khaled Al Khodari
Raad Alhaj Tahtouh

Khaled Al Khodari

and 3 more

August 09, 2022
A 40-year-old patient with a known case of uncontrolled hyperthyroidism was admitted secondary to acute ST-segment elevation myocardial infarction and thyroid storm. Acute medical therapy was started followed by a coronary angiogram because he developed signs of heart failure. There were no complications, and he was discharged in stable condition.
Hybrid VSD closure in a 4.5 kgs Neonate Case Report and Literature Review
Andriana Anagnostopoulou
Nicholaos Eleftherakis

Andriana Anagnostopoulou

and 3 more

August 09, 2022
Ventricular septal defects are the most common congenital heart defects. They account for approximately 20% of all forms of congenital heart disease as an isolated lesion. Perimembranous Ventricular septal defects are the most common form (70%), followed by muscular (15–20%).Muscular VSDs are a challenging problem in neonates and infants when they present with significant congestive heart failure from interventricular shunting. However, with careful adjustments to technique, most of these can be closed.
Minimally Invasive Mitral Valve Surgery with or without Robotics: Examining the Evide...
Hiroto Kitahara
Husam Balkhy

Hiroto Kitahara

and 1 more

August 09, 2022
Minimally invasive mitral valve surgery can be performed with or without robotic assistance. In this issue of the journal Zheng et al compare between these two approaches in a propensity matched study over a 5 year period and show that the two techniques have similar successful short and mid term outcomes. Although we are proponents of the robotic approach, we agree with their conclusions and discuss in this commentary some of the previously published studies that have shown similar findings.
Long-term, room temperature storage of DNA extract on filter paper
Katherine Izenour
Anwar Kalalah

Katherine Izenour

and 3 more

August 09, 2022
1. Stable nucleic acid storage and preservation in resource limited settings is often a barrier to widespread pathogen surveillance. 2. Dried Blood Spot (DBS) filter paper has a long history of preserving nucleic acid in whole blood, we tested extending this technology to the room temperature storage of DNA extract. 3. We found that DNA extracted from whole mammalian blood can be stored at room temperature on DBS filter paper, then washed with the buffer solution Tris-HCL, and used in downstream PCR analysis with results comparable to PCR performed on DNA extracted from whole blood dried on DBS filter paper which is the gold standard. 4. The success of this method means DNA can be stored at room temperature making sharing genomic samples easier by eliminating the need for cold chain.
Papillary fibroelastoma of the pulmonary valve: a 14-year follow-up
Pedro Henrique de Borba Engster
Said Alsidawi

Pedro Henrique de Borba Engster

and 1 more

August 09, 2022
Primary cardiac tumors are exceedingly rare. Among them, papillary fibroelastomas (PFEs) are the third most common. These tumors are often incidental findings but can also precipitate a myriad of clinical presentations, mainly embolic events. Most common in the left-sided valves, PFEs rarely occur in the right side of the heart. They are usually resected surgically following diagnosis, thwarting assessment of their natural history. We present the case of a woman diagnosed with pulmonary valve PFE following recurrent pulmonary embolism who did not undergo surgery, allowing for an extended follow-up of the condition.
Neurological Manifestations of Chronic Methadone Maintenance Therapy: Case Report and...
Ulviyya Gasimova
Khurram  Afzal

Ulviyya Gasimova

and 2 more

August 09, 2022
Methadone is a long-acting opioid medication used for maintenance therapy in heroin addiction. Presenting a case of a patient on methadone therapy who developed neurological complications as mental status changes and choreiform movements. Workup revealed lesions involving the subcortical white matter and basal ganglia. and movements improved with treatment.
Effects of light size and intensity on photoconductive effect-based optically-induced...
Huanzhou Yang
Zuobin Wang

Huanzhou Yang

and 1 more

August 09, 2022
In this paper, the effect of light size and intensity on photoconductive effect-based optically-induced dielectrophoresis (ODEP) for three-dimensional manipulation of cells is studied. The photoconductive effect-based ODEP enabled the three-dimensional manipulation of multiple cells, whether normal cells or cancer cells. When the light spot size is similar to the cell and the photoconductive layer resistance is about 150 MΩ, the spot repels other cells after manipulating a single cell. When the light spot size is much larger than the cell and the photoconductive layer resistance is about 120 MΩ, multiple cells are controlled inside the spot and distributes in the same plane. When the light intensity is increased and the photoconductive layer resistance is about 40 MΩ, the cells are manipulated in three-dimensions. Using a light spot similar in size to the cells to gather specific cells at different locations into a specific area, and then increasing the light intensity enabled three-dimensional manipulation. We find that the cells three-dimensional manipulation by ODEP is achieved only when the photoconductive effect induced by the light pattern reaches a higher intensity. The realization of ODEP-based three-dimensional manipulation is related to the spot size and the photoconductive layer resistance determined by light intensity.
A low-power and area-efficient ultrasound receiver using beamforming SAR ADC with CDA...
Seungah Lee
Soohyun Yun

Seungah Lee

and 2 more

August 09, 2022
We present a low-power area-efficient subarray beamforming receiver (RX) structure for a miniaturized 3-D ultrasound imaging system. Given that the delay-and-sum (DAS) and digitization functions consume most of the area and power in the receiver, the beamforming successive approximation register (SAR) analog-to-digital converter (ADC) shares its capacitive digital-to-analog converter (CDAC) with the delay cells. As a result, the delay cells implemented with capacitors are embedded in the CDAC with significant area reduction, further eliminating the need for power-hungry ADC buffers. Furthermore, the dual reference 10-bit SAR ADC reduces the area of CDAC by 32 times, achieving a switching energy reduction of 98.3%, compared to the conventional SAR ADC. As a result, the proposed beamforming SAR ADC, simulated using a 0.18 μm CMOS process, consumes 230 μW per channel, significantly reducing the per channel capacitance.
Deep Learning Models for Analysis of Non-Destructive Evaluation Data of Reinforced Co...
Dayakar Naik Lavadiya
Sattar Dorafshan

Dayakar Naik Lavadiya

and 1 more

August 09, 2022
Application of deep learning (DL) for automatic condition assessment of bridge infrastructure has been on the rise in the last few years. From the published literature, it is evident that lot of research efforts has been put in identifying the surface defects such as cracks, potholes, spalling etc. using deep learning. However, a concrete bridge deck health is jeopardized by the presence of subsurface defects substantially, however, the task of defect detection using deep learning has not received the proper attention. The goal of this survey paper is to provide a critical review of existing technical knowledge for DL application on NDE data for bridge deck evaluation. The authors reviewed prominent NDE techniques for subsurface defect detection of bridge decks and explored the various DL models proposed to identify these defects. First a brief overview of the working principle of NDE techniques and DL architectures is provided, and then the information about proposed DL models and their efficacy is highlighted. Based on the existing knowledge gaps, various challenges and future prospects associated with application of DL in bridge subsurface inspection are discussed.
Erdheim-Chester disease: a multisystem disease case illustration with rare manifestat...
maysam jridi
Tayssir Ben Achour

maysam jridi

and 7 more

August 09, 2022
Erdheim-Chester disease is a rare multisystemic disease. A 50-year-old woman, presented with a recurrent pain and swelling of the left knee. Bone scintigraphy showed increased tracer uptake of peripheral skeleton. The computed tomography showed tissular infiltration in the retroperitoneum, around the vessels. Immunohistochemistry showed CD68 (+) and CD1a (-).
Molecular Determinants of Tetrahydrocannabinol Binding to the Glycine Receptor
Lautaro D. Alvarez
N. R. Carina Alves

Lautaro D. Alvarez

and 1 more

August 09, 2022
The recognition of Cannabis as a source of new compounds suitable for medical use has attracted strong interest from the scientific community in its research, and substantial progress has accumulated regarding cannabinoids’ activity; however, a thorough description of their molecular mechanisms of action remains a task to complete. Highlighting their complex pharmacology, the list of cannabinoids’ interactors has vastly expanded beyond the canonical cannabinoid receptors. Among those, we have focused our study on the glycine receptor (GlyR), an ion channel involved in the modulation of nervous system responses, including, to our interest, sensitivity to peripheral pain. Here, we report the use of computational methods to investigate possible binding modes between the GlyR and Δ 9-tetrahydrocannabinol (THC). After obtaining a first pose for the THC binding from a biased molecular docking simulation and subsequently evaluating it by molecular dynamic simulations, we found a dynamic system with an identifiable representative binding mode characterized by the specific interaction with two transmembrane residues (Phe293 and Ser296). Complementarily, we assessed the role of membrane cholesterol in this interaction and positively established its relevance for THC binding to GlyR. Lastly, the use of restrained molecular dynamics simulations allowed us to refine the description of the binding mode and of the cholesterol effect. Altogether, our findings contribute to the current knowledge about the GlyR-THC mode of binding and propose a new starting point for future research on how cannabinoids in general, and THC in particular, modulate pain perception in view of its possible clinical applications.
Respiratory virome profiles reflect antiviral immune responses
Judit Rovira Rubió
spyridonmegremis

Judit Rovira Rubió

and 13 more

August 09, 2022
Background: From early life, respiratory viruses are implicated in the development, exacerbation and persistence of respiratory conditions such as asthma. Complex dynamics between microbial communities and host immune responses, shape immune maturation and homeostasis, influencing health outcomes. We evaluated the hypothesis that the respiratory virome is linked to systemic immune responses, using peripheral blood and nasopharyngeal swab samples from preschool-age children in the PreDicta cohort. Methods: Peripheral blood mononuclear cells from 51 children (32 asthmatics, 19 healthy controls), participating in the 2-year multinational PreDicta cohort were cultured with bacterial (Bacterial-DNA, LPS) or viral (R848, Poly:IC, RV) stimuli. Supernatants were analyzed by Luminex for the presence of 22 relevant cytokines. Virome composition was obtained using untargeted high troughput sequencing of nasopharyngeal samples. The metagenomic data were used for the characterization of virome profiles and the presence of key viral families (Picornaviridae, Anelloviridae, Siphoviridae). These were correlated to cytokine secretion patterns, identified through hierarchical clustering and principal component analysis. Results: High spontaneous cytokine release was associated with increased presence of Prokaryotic virome profiles and reduced presence of Eukaryotic and Anellovirus profiles. Antibacterial responses did not correlate with specific viral families or virome profile, however, low antiviral responders had more Prokaryotic and less Eukaryotic virome profiles. Anelloviruses and Anellovirus-dominated profiles were equally distributed amongst immune response clusters. The presence of Picornaviridae and Siphoviridae was associated with low interferon-λ responses. Asthma or allergy did not modify these correlations. Conclusions: Antiviral cytokines responses at a systemic level reflect the upper airway virome composition. Individuals with low innate interferon responses have higher abundance of Picornaviruses (mostly Rhinoviruses) and bacteriophages. Bacteriophages, particularly Siphoviridae appear to be sensitive sensors of host antimicrobial capacity, while Anelloviruses are not affected by TLR-induced immune responses.
Failure analysis of the PPS-based bag filters in coal-fired power plants:a surface st...
Bing Zhang
Wei Wang

Bing Zhang

and 7 more

August 09, 2022
Owing to the complicated environments, the service life of bag-filter or electrostatic-bag composite precipitators with polyphenylene sulfide (PPS)-based bag-filter materials is greatly deviated from the ideal time. In this paper, the structural transformation of PPS-based bag filter materials collected from the coal-fired power plants with different loading units were investigated systematically. As the SO2 content increases, the surface evolution of PPS fibers from smoothness to crack occurs.The major reason for the failure of PPS-based bag filters is that working temperature (T) often passes through acid dew gas point (Ta), and the SO3 would be produced during the condensing of H2SO4 when T is lower than Ta. This work discloses the actual structural evolution of PPS and some corresponding rules under the complicated corrosive gases with high temperatures, which provides a guidance for prolonging the service life of PPS-based bag filters during the usage of coal-fired power plant
Intensification of mass and heat transfer at the bottom of a stirred tank reactor by...
Mohamed El-Naggar
Esraa Abdel-Gawad

Mohamed El-Naggar

and 4 more

August 09, 2022
In an attempt to obviate the costly and protracted separation of final products from powdered catalyst particles in stirred slurry catalytic reactors, the electrochemical technique was used in the present study to determine mass transfer in a stirred vessel equipped with different baffle configurations placed at the tank bottom. Additionally, the effect of baffle tube diameters, as well as the impeller speed and geometry were examined. Mass transfer data obtained were correlated using the governing dimensionless groups from which heat transfer rates can be deduced by analogy. Results revealed the merits of using tubular baffles in terms of mass transfer and consequently heat transfer enhancement. Besides acting as a catalyst support where liquid-solid diffusion-controlled catalytic reactions, electrochemical reactions, photochemical reactions, and immobilized enzyme-catalyzed biochemical reactions take place, a tubular baffle can act also as a built-in cooler, in case of highly exothermic reactions to avoid hot spots and catalyst deactivation.
← Previous 1 2 3 4 5 6 7 8 9 10 11 12 … 992 993 Next →
Authorea
  • Home
  • About
  • Product
  • Preprints
  • Pricing
  • Blog
  • Twitter
  • Help
  • Terms of Use
  • Privacy Policy