Investigation of the ultrasound-induced collapse of air bubbles near soft materials.

A numerical investigation into the ultrasound-induced collapse of air bubbles near soft materials, utilizing a novel multi-material diffuse interface method (DIM) model with block-structured adaptive mesh refinement is presented. The present work expands from a previous five-equation DIM by incorporating Eulerian hyperelasticity. The model is applicable to any arbitrary number of interacting fluid and solid material. A single conservation law for the elastic stretch tensor enables tracking the deformations for all the solid materials. A series of benchmark cases are conducted, and the solution is found to be in excellent agreement against theoretical data. Subsequently, the ultrasound-induced bubble-tissue flow interactions are examined. The bubble radius was found to play a crucial role in dictating the stresses experienced by the tissue, underscoring its significance in medical applications. The results reveal that soft tissues primarily experience tensile forces during these interactions, suggesting potential tensile-driven injuries that may occur in relevant treatments. Moreover, regions of maximal tensile forces align with tissue elongation areas. It is documented that while early bubble dynamics remain relatively unaffected by changes in shear modulus, at later stages of the penetration processes and the deformation shapes, exhibit notable variations. Lastly, it is demonstrated that decreasing standoff distances enhances the interaction between bubbles and tissue, thereby increasing the stress levels in the tissue, although the behavior of the bubble dynamics remains largely unchanged

Numerical study of real gas effects during bubble collapse using a disequilibrium multiphase model

An explicit density-based solver of the Euler equations for inviscid and immiscible gas-liquid flow media is coupled with real-fluid thermodynamic equations of state supporting mild dissociation and calibrated with shock tube data up to 5000 K and 28 GPa. The present work expands the original 6-equation disequilibrium method by generalising the numerical approach required for estimating the equilibrium pressure in computational cells where both gas and liquid phases co-exist while enforcing energy conservation for all media. An iterative numerical procedure is suggested for taking into account the properties of the gas content as derived from highly non-linear real gas equations of state and implemented in a tabulated form during the numerical solution. The developed method is subsequently used to investigate gaseous bubble collapse cases considering both spherical and 2D asymmetric arrangements as induced by the presence of a rigid wall. It is demonstrated that the predicted maximum temperatures are strongly influenced by the equations of state used; the real gas model predicts a temperature reduction in the bubble interior up to 41% space-averaged and 50% locally during the collapse phase compared to the predictions obtained with the aid of the widely used ideal gas approximation

Prospects of quality protein maize as feed for indigenous chickens in Zimbabwe: A review

Indigenous chickens (IC) play an important role in African rural household settings, particularly in improving their livelihoods. However, IC production is characterised by low productivity due to poor quality and quantity of feed, compounded by poor management practises. This dire situation is aggravated by the fact that IC are raised under extensive systems, supplemented with meagre grain supplements. They are a hardy poultry species and as a result most farmers assume that their nutritional requirements can be met through scavenging. To the contrary, analysis of crop contents has shown that IC nutritional intake levels are often below optimum for production. To enhance the productivity of IC, there is urgent need to explore the use of alternative nutritionally rich feed stuffs. One of such ingredients is Quality Protein Maize (QPM). Quality protein maize contains elevated levels of lysine and tryptophan, compared to non-QPM. The objective of this article is to review the prospects of QPM as feed for IC, through a strengths, weaknesses, opportunities and threats analysis. Due to its superior nutritional quality, QPM has the potential to enhance growth rate, carcass characteristics and immunity of indigenous chickens. However, QPM is still a new technology in Zimbabwe; most farmers are not aware of its existence. There is, therefore, need for policies and infrastructural adjustments to promote its widespread adoption. Furthermore, there is need for feeding trials as they provide concrete evidence of the benefits of this kind of maize.Les poulets \ua0indig\ue8nes (CI) jouent un r\uf4le important dans les m\ue9nages ruraux africains, en particulier pour am\ue9liorer leurs moyens de subsistance. Cependant, la production de circuits int\ue9gr\ue9s se caract\ue9rise par une faible productivit\ue9 due \ue0 la qualit\ue9 et quantit\ue9 d\u2019aliment m\ue9diocres, aggrav\ue9es par de mauvaises pratiques de gestion. Cette situation d\ue9sastreuse est aggrav\ue9e par le fait que les CI sont cultiv\ue9es dans le cadre de syst\ue8mes \ue9tendus, compl\ue9t\ue9s par de maigres suppl\ue9ments de c\ue9r\ue9ales. C\u2019est une esp\ue8ce de volaille robuste et, par cons\ue9quent, la plupart des agriculteurs pensent que leurs besoins nutritionnels peuvent \ueatre satisfaits gr\ue2ce au nettoyage. Au contraire, l\u2019analyse du contenu des cultures a montr\ue9 que les niveaux d\u2019apport nutritionnel en IC sont souvent inf\ue9rieurs \ue0 l\u2019optimum pour la production. Pour am\ue9liorer la productivit\ue9 des circuits int\ue9gr\ue9s, il est urgent d\u2019explorer l\u2019utilisation de produits de substitution pour aliments riches en aliments. Un de ces ingr\ue9dients est le ma\uefs \ue0 prot\ue9ines de qualit\ue9 (QPM). QPM contient des niveaux \ue9lev\ue9s de lysine et de tryptophane par rapport au ma\uefs non-QPM. L\u2019objectif de cet article est d\u2019examiner les perspectives de QPM en tant que source pour IC, \ue0 travers une analyse SWOT. Gr\ue2ce \ue0 sa qualit\ue9 nutritionnelle sup\ue9rieure, le QPM peut potentiellement am\ue9liorer le taux de croissance, les caract\ue9ristiques de la carcasse et l\u2019immunit\ue9 des poulets indig\ue8nes. Cependant, le QPM est encore une nouvelle technologie au Zimbabwe; la plupart des agriculteurs ne sont pas au courant de son existence. Des politiques et des ajustements d\u2019infrastructures sont donc n\ue9cessaires pour promouvoir son adoption \ue0 grande \ue9chelle. En outre, des essais d\u2019alimentation sont n\ue9cessaires car ils fournissent des preuves concr\ue8tes des avantages de ce type de ma\uefs

Prediction of shock heating during ultrasound-induced bubble collapse using real-fluid equations of state

Numerical simulations of collapsing air bubbles considering complex and more accurate equations of state (EoS) for estimating the properties of both the liquid and gas are presented. The necessity for utilising such EoSs in bubble collapse simulations is illustrated by the unphysical (spurious) liquid temperature jump formed in the vicinity of the bubble-air interface when simplified EoSs are used. The solved fluid flow equations follow the mechanical equilibrium multiphase method of Kapila. The solver is coded in the AMReX platform, enabling high-performance computation with parallel processing and Adaptive Mesh Refinement for speeding up simulations. It is initially demonstrated that the frequently used Stiffened Gas (SG) EoS overpredicts the liquid temperature at high compression. More sophisticated EoS models, such as the International Association for the Properties of Water and Steam (IAPWS), the Modified Noble Abel Stiffened Gas (MNASG) and a modified Tait EoS introduced here, are also implemented into the flow solver and their differences are highlighted for bubble collapse cases for the first time. Subsequently, application of the developed model to cases of practical interest is showcased. More specifically, simulations of bubble collapse near a solid wall are presented for conditions simulating shock wave lithotripsy (SWL). It is concluded that for such cases, a maximum increase of 25 K of the liquid temperature in contact along the solid wall is caused during the collapse of the air bubble due to shock wave focusing effects. It is also highlighted that the maximum liquid heating varies depending on the initial bubble-wall stand-off distance

Can low-dose of ketamine reduce the need for morphine in renal colic? A double-blind randomized clinical trial

Background: The combination of morphine with low doses of ketamine (MK) has been utilized in the Emergency Department (ED) compared with morphine and placebo (MP) for the treatment of acute pain in few studies. The purpose of this study was to compare the effect of MP with MK for the treatment of severe pain with renal colic of patients who had been referred to the ED. Methods: This study is a double blind randomized clinical trial on patients with severe renal colic pain who were referred to the ED. Patients were enrolled with pain severity of at least 6 of the 10 visual analogue scales (VAS). Patients were divided into two groups: Morphine 0.1 mg/kg and placebo (MP group) and morphine 0.1 mg/kg and ketamine 0.15 mg/kg (MK group). Pain of patients was studied in 10, 30, 60, 90, and 120 min after injection. Results: Totally, 106 patients were enrolled in study groups. Assessment of the average pain during 120 min at 10 and 30 min after the start in the drug, MK group was significantly lower than the MP group (p = 0.019 and p = 0.003 respectively). Conclusion: Given that combinations of morphine with low doses of ketamine in patients with renal colic pain causes more pain and morphine consumption reduction then this combination is suggested as an alternative treatment that could be utilized in patients with renal colic. © 201

First and Second Law Analyses of Trans-critical N2O Refrigeration Cycle Using an Ejector

An ejector-expansion refrigeration cycle using nitrous oxide was assessed. Thermodynamic analyses, including energy and exergy analyses, were carried out to investigate the effects on performance of several key factors in the system. The results show that the ejector-expansion refrigeration cycle (EERC) has a higher maximum coefficient of performance and exergy efficiency than the internal heat exchanger cycle (IHEC), by 12% and 15%, respectively. The maximum coefficient of performance and exergy efficiency are 14% and 16.5% higher than the corresponding values for the vapor-compression refrigeration cycle (VCRC), respectively. The total exergy destruction for the N2O ejector-expansion cycle is 63% and 53% less than for IHEC and VCRC, respectively. Furthermore, the highest COPs for the vapor-compression refrigeration, the internal heat exchanger and the ejector-expansion refrigeration cycles correspond to a high side pressure of 7.3 MPa, and the highest COPs for the three types of CO2 refrigeration cycles correspond to a high side pressure of 8.5 MPa. Consequently, these lead to a lower electrical power consumption by the compressor

Can low-dose of ketamine reduce the need for morphine in renal colic? A double-blind randomized clinical trial

Background: The combination of morphine with low doses of ketamine (MK) has been utilized in the Emergency Department (ED) compared with morphine and placebo (MP) for the treatment of acute pain in few studies. The purpose of this study was to compare the effect of MP with MK for the treatment of severe pain with renal colic of patients who had been referred to the ED. Methods: This study is a double blind randomized clinical trial on patients with severe renal colic pain who were referred to the ED. Patients were enrolled with pain severity of at least 6 of the 10 visual analogue scales (VAS). Patients were divided into two groups: Morphine 0.1 mg/kg and placebo (MP group) and morphine 0.1 mg/kg and ketamine 0.15 mg/kg (MK group). Pain of patients was studied in 10, 30, 60, 90, and 120 min after injection. Results: Totally, 106 patients were enrolled in study groups. Assessment of the average pain during 120 min at 10 and 30 min after the start in the drug, MK group was significantly lower than the MP group (p = 0.019 and p = 0.003 respectively). Conclusion: Given that combinations of morphine with low doses of ketamine in patients with renal colic pain causes more pain and morphine consumption reduction then this combination is suggested as an alternative treatment that could be utilized in patients with renal colic. © 201

Canine transmissible venereal tumor and seminoma: a cytohistopathology and chemotherapy study of tumors in the growth phase and during regression after chemotherapy (Retraction of Vol 35, Pg 5493, 2014)

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