Numerical analysis and optimization of key parts in the stirred tank based on solid-liquid flow field

In order to further improve the mixing performance of the mixing device, the structure of the agitator was optimized, and the effects of the diameter and pitch of the agitator on the solid-liquid suspension characteristics were analyzed by single factor method. Multiple reference frame (MRF), computational fluid dynamics, Euler multiphase flow model and standard K- ε turbulence model were used to investigate the effect of the height from the bottom of the agitator on the suspension characteristics of particles in the agitator was studied. The results show that reducing the height from the bottom of the agitator can promote the suspension of particles at the bottom of the tank, but too low height from the bottom will easily produce mixing dead zone at the bottom of the tank, and cause the accumulation of particles. Reducing the height of the agitator from the bottom will enlarge the clear liquid area of the flow field, cause uneven particle distribution and increase the stirring torque. With the increase of agitator diameter, the critical suspension speed of the flow field decrease, but the stirring power required by the flow field increase. Increasing the blade spacing in a certain range can promote the suspension of particles and make the distribution of particles in the flow field more uniform. Therefore, the mixing power and the uniformity of particle concentration distribution need to be considered together in order to make the mixing device more efficient and energy-saving.

Treatment of ultrahigh chemical oxygen demand chemical wastewater by Fenton oxidation

The article focuses on the Fenton oxidation process for the treatment of ultrahigh COD chemical wastewater from chemical plants. Optimum pH was determined as 2.0 and 10.0 for the first (oxidation) and second stage (coagulation) of the Fenton process, respectively. 0.465gFeSO4·7H2O, H2O2(30%)2ml, the mole tatio of H2O2 : Fe2+=10:1, adjust the pH of the solution to 10, after 1.5 hours of agitation, then add 5% PAM2ml to the solution, filtrate, extract, filtrate the clear liquid and dilute it three times, take 200ml of the diluted liquid, and add 0.465gFeSO4·7H2O, H2O2(30%)2ml, the mole tatio of H2O2 : Fe2+=10:1, adjust the pH of the solution to 10, after 1.5 hours of agitation, then add 5% PAM2ml to the solution, static stratification. For chemical wastewater, when the molar ratio H2O2/Fe2+ is 10:1, the removal rate of COD is the highest, provided 86.21–86.45% COD removal.

Formulation and evaluation of dry herbal powder shampoo

Shampoos are used not only for cleansing purpose but also for imparting gloss to hair and to maintain their manageability and oiliness for hair. Shampoos are of various types, like powder shampoo, clear liquid shampoo liquid shampoo, lotion shampoo, solid gel shampoo, medicated shampoo, liquid herbal shampoo etc. As far as herbal shampoos are concerned in stability criteria. Depending upon the nature of the ingredients they may be simple or plain shampoo, antiseptic or antidandruff.In the present work the herbal shampoo powder has been developed, by using traditional drugs for hair care. The preparation were formulated using Onion Powder, Rose Petal, Lemon Grass, Flaxseed or Linseed, Hirda, Bahera, Black tea, Brahmni, Triphala, Bhringraj, Ginger Root, Ashwagadha, Shikakai, Feenu greek, Shatavari, Heena, Wala, Aloevera Powder, Nirgudi Powder, Bavachi, Jatha mansi, Tulsi, Neem, Hibiscus Flower, and Retha evaluated for organoleptic properties, powder characteristics, foam test and physical evaluation.The physicochemical evaluation of the formulated shampoo showed ideal results. However, to improve its quality, product performance, and safety, further development and study was required.

Relationship Between Meibomian Gland Loss in Infrared Meibography and Meibum Quality

BackgroundIn this study, to determine the correlation between meibomian gland loss (dropout) and meibum quality, we evaluated the correlation between meibomian gland dropout in the central eight meibomian glands of the eyelid and meibum quality in the same central eight meibomian glands of the eyelid.MethodsNinety nine eyes of 91 patients were included in the study. Dropout at the central eight meibomian glands of eyelids was graded as grade 0,1,2,3 according to the dropout area. The meibum quality was graded as follows: grade 0, no secretion; 1, inspissated/toothpaste consistency, 2: cloudy liquid secretion, and 3: clear liquid secretion. For 68 eyes of 68 patients, correlation analysis between dropout and meibum quality was performed. To precisely analyze the direct correlation between meibomian gland dropout in meibography and meibum quality, we evaluated 31 eyes of 23 patients with focal dropout in meibography.ResultsThe mean meiboscore (±SD) was 1.1±1.1 in the upper eyelids and 0.7±1.0 in the lower eyelids. The mean meibum quality grade (±SD) was 2.3 ±0.9 in the upper eyelids and 1.3±0.6 in the lower eyelids. There was no significant correlation between the meiboscore and the meibum quality grade in the upper (p =0.445) and lower (p =0.405) eyelids. Analysis of the direct correlation between meibomian gland dropout in meibography and meibum quality in patients with focal dropout (loss of 1 or 2 adjacent meibomian glands), however, indicated that meibomian glands with dropout secrete little to no meibum.ConclusionsOverall, there appeared to be no relationship between meibomian gland dropout and the meibum quality, but more detailed investigation of each meibomian gland alone revealed that meibomian glands with dropout secrete little to no meibum.

Pre-operative fasting times for clear liquids at a tertiary children’s hospital; what can be improved?

Background: The goal of preoperative fasting is to prevent pulmonary aspiration during general anesthesia. Fasting times are often prolonged leading to patient discomfort and risk for adverse events. This retrospective quality improvement survey evaluated effective nil-per-os (NPO) times and causes for prolonged NPO times with the aim to suggest improvement strategies by a newly founded fasting task force.Methods: Data from all electronic anesthesia records from 2019 at our institution were reviewed for fasting times. Our NPO instructions follow American Society of Anesthesiology guidelines and are calculated based on the patient’s arrival time (90 min before OR time). Primary outcome was the effective NPO time for clear liquids, secondary outcomes were incidence of delays and the parental compliance with the NPO instructions. Data are presented as median (interquartile range).Results: 9,625 cases were included in the analysis. NPO time was documented in 72.1% with a median effective NPO time of 7:13 h (7:36). OR in room times were documented in 72.8%, 2,075 (29.5%; median time 0:10 h [0:21]) were earlier and 4,939 (70.5%; median time 0:29 h [0:54]) were later than scheduled. Parental NPO compliance showed a median deviation for clear liquid intake of 0:55 h (8:30).Conclusions: This study revealed that effective NPO times were longer than current ASA guidelines. Contributing causes include case delays and parental non-compliance to NPO instructions. Thus, task force recommendations include change NPO instruction calculations to scheduled OR time versus arrival time, and encourage parents to give their child clear liquids at the instructed time.

An opioid receptor independent mechanism underlies motility dysfunction and visceral hyperalgesia in opioid-induced bowel dysfunction

Background and Aims: Constipation and abdominal pain are commonly encountered in opioid-induced bowel dysfunction (OBD). The underlying mechanisms are incompletely understood, and treatments are not satisfactory. As OBD patients often have fecal retention, we aimed to determine whether fecal retention plays a pathogenic role in the development of constipation and abdominal pain in OBD, and if so to investigate the mechanisms. Methods: A rodent model of OBD was established by daily morphine treatment at 10 mg/kg for 7 days. Bowel movements, colonic muscle contractility, visceromotor response to colorectal distention, and cell excitability of colon-projecting dorsal root ganglion neurons were determined in rats fed in normal pellet food, or in clear liquid diet. Results: Morphine treatment (Mor) reduced fecal outputs starting on day 1, and caused fecal retention afterwards. Compared to controls, Mor rats demonstrated suppressed muscle contractility, increased neuronal excitability and visceral hypersensitivity. Expression of cyclooxygenase-2 (COX-2) and nerve growth factor (NGF) was up-regulated in smooth muscle of the distended colon in Mor rats. However, prevention of fecal retention by feeding rats with clear liquid diet blocked up-regulation of COX-2 and NGF, restored muscle contractility, and attenuated visceral hypersensitivity in Mor rats. Moreover, inhibition of COX-2 improved smooth muscle function and fecal outputs, whereas anti-NGF antibody administration attenuated visceral hypersensitivity in Mor rats. Conclusions: Morphine-induced fecal retention is an independent pathogenic factor for motility dysfunction and visceral hypersensitivity in OBD rats. Liquid diet may have therapeutic potential for OBD by preventing fecal retention-induced mechano-transcription of COX-2 and NGF.