Forced Convection Cooling of Electric Motors Using Enhanced Surfaces

Electric motors are extensively engaged in industrial and commercial applications such as electrical cars, energy-conversion systems, elevators, and actuators for aircrafts. Due to the significant internal heat generation, it is usually a challenge to design and manufacture high power density, high reliability, and low cost electric motors with superior performance. One of the efficient ways to dissipate the heat generated in the electrical motor is by using extended surfaces (i.e. heat sinks). These surfaces are extruded from the motor casing and air is forced though them by a cooling fan. This cooling approach is simple to be implemented and has zero carbon emission to the environment. Adding ribs on the motor extended surface enhances the heat dissipation rate. This project is intended to study numerically the effect of varying ribs spacing and ribs heights on heat removal efficiency, accounting for the relative change in heat transfer coefficient and pressure drop compared to those for a smooth flow channel. The study is conducted to simulate the airflow field, and heat transfer for a plate heat sink using ANSYS V.16. The domain considered in the present work is a simple design of an electric motor annulus. The electric motor annulus consists of an array of ribbed fins. Heat source is represented as a uniform heat flux of 12250 W/m2 at the bottom surface of the heat sink base. Through the simulations, the rib heights (e=0.05, 0.1, 0.2, in mm) and spacing (p=1, 2,3,4,5, in mm) between the ribs, the channel width (Wch= 2 and 6 in mm), and the rib configuration (continues and inline ribs) are varied to study their effect on the performance of the heat sink for a Reynolds number range from 3133 to 12532. To assess which rib configuration is best, a figure of merit (named as thermal-hydraulic performance) is used which is defined as the ratio of heat transfer enhancement to the increase in pumping power due to the presence of the ribs. The highest thermal-hydraulic performance value out of all the transverse cases at Wch=2 mm in this study was 1.07 at e=0.05 mm, p=4 mm, and Re=3133 which means only a 7% enhancement is obtained. These set of cases are suitable for increasing the rate of heat transfer while ignoring the pressure drop penalty. Changing the channel width to 6 mm increases the thermal-hydraulic performance by about 23%. Therefore, this channel width is used for the inline ribs configurations with seven different opening ratios (10% to 70%). The inline ribs are investigated at two different Reynolds number (3133 and 12532). At an opening ratio of 50% the highest thermal-hydraulic performance of 1.18 and 1.22 were found at Re=3133 and p=5 mm, and at Re=3133 and p=1 mm, respectively. These simulation results show that with proper channel and ribs configuration, one can achieve about 22% increase in the thermal-hydraulic performance ratio over that of the smooth channel

SUPPLEMENTS TO REDUCE METHANE PRODUCTION IN RUMINANT ANIMALS

Changes in the climate continue to be one of the world\u27s most pressing issues. The accumulation methane (CH4) in the atmosphere is a major driver of these changes. Ruminant animals have been identified as substantial contributors to CH4 emissions. This assertion is supported by the fact that ruminant animals have a unique digestive tract that allows them to digest complex polysaccharides by the action of microbes in their rumen. During the microbial digestion (fermentation) of dietary polysaccharides, CH4 is produced as a byproduct of the process. Therefore, this paper aims to analyze this issue, highlight how ruminants contribute to this phenomenon and suggest measures that can be implemented to mitigate CH4 production by these animals. Research studies in recent years have tested if different supplements may reduce CH4 emissions from ruminant animals by suppressing some of the methane-producing microbes in the rumen or by altering the hydrogen (H2) utilization in the rumen. Results in this paper showed that some of the tested supplements (e.g. Ionophores, tannins, essential oils (EO), nitrate, bioflavonoids, and enzymes) or their combinations can decrease CH4 production in the rumen without significantly affecting animals performance or rumen fermentation. However, the results were not always consistent depending on the supplement dosage and treatment diets composition. Although some of the tested supplements showed promising effects, more research is still needed to assess the long-term effects for some of these supplements as rumen microbial adaptation may weaken the reported effects

Preparation And Characterization Of Acitretin-Loaded Niosomes For Psoriasis Treatment

Psoriasis is a chronic skin disease that manifests as impaired epidermal differentiation. The disease is typically treated with acitretin, an effective oral cytotoxic agent. However, due to its side effects, its use is highly limited. Topical delivery of acitretin may decrease the systemic toxicity and increase the drug’s bioavailability at the pathological site. However, this approach has some limitations. The decrease in skin integrity due to psoriasis could lead to escape of drug into the systemic circulation system and consequently compromise the topical approach. Also, the high instability of acitretin in the presence of heat could limit its topical application. The aim of this work is to formulate and characterize niosomes for topical delivery of acitretin in order to decrease the drug’s systemic side effects, provide a controlled method of delivery to the pathological site, and improve the thermal stability of acitretin. To achieve this goal, acitretin niosomes were prepared using the thin film hydration technique. The niosomes were then characterized and optimized for size, entrapment efficiency, and drug release. The characterized niosomes were evaluated and investigated as a topical drug delivery system. The lead formulation displayed an optimum particle size of 471±1.15 nm with a PDI of 0.4±0.04, zeta potential of -21±0.26, entrapment efficiency of 92±2.70, and controlled drug release of 30.80±0.21 %. In vitro permeation studies across a tab-stripped epidermis shothat niosomes can control the drug permeation of compromised skin. The cumulative amount of drug permeated from niosomes was 1.87±0.09 µg/cm2, compared to 3.6±0.02 µg/cm2 with drug control and 2.4±0.08 µg/cm2 with excipient control. Also, the in vitro deposition studies shothat the amount of the drug deposited from niosomes to the epidermis after stratum corneum removal (665±0.2 ng/mg) was significantly greater than the amount of the drug in the solution and excipient control (385±0.1 and 205±0.4 ng/mg, respectively). Moreover, in vitro thermal degradation studies confirmed that the acitretin niosome formulations have a longer half-life than the drug in solution (115.75 days for samples stored at 4 °C, 60.18 days for samples stored at 24 °C, and 45.59 days for samples stored at 40 °C). In summary, the results shothat the incorporation of acitretin into niosomes for topical delivery might be a promising approach for the treatment of psoriasis

Biodiversity of Nematode Antagonistic Fungi under Vegetation of Province Khulais, Western of Saudi Arabia Kingdom

The diversity and community structure of nematode trapping fungi (NTF) were investigated in thirteen sites located in province of Khulais, western of Kingdom of Saudi Arabia with different vegetation. NTF were isolated by using sprinkle technique. The soil pH value, soil texture and organic matters percentages of each soil sample were analyzed to investigate the relationship between these environmental factors and the occurrence of nematode trapping and parasitic fungi. Three species of nematode antagonistic fungi genera were found and identified in this study. The Hyphomycetes fungus Dactylaria brochopaga Drechsier, was isolated from 9 sites by rate 69.2% from total collected sites. The fungus was found naturally trapping of second stage juveniles (J2s) for 3 nematode orders distributed between 6 plant species in soil samples containing organic matters more than 1.5%. The occurrence of D. brochopaga Drechsier was reduced when amount of organic matter in soil samples was less than 1%. The optimal pH value for growth of D. brochopaga Drechsier in natural habitat was ranged from 6.5 to 7.1 in sandy loamy soil texture. In addition, two species of the Chytridiomycetous fungi Catenaria were observed in 11 sites by rate 84.6% of total sites. One of them was identified as C. anguillulae Sorokin, which found parasitized on nematode body causing the breakdown of the nematode cuticle in 8 sites with different plants. While, the  another specie was identified as C. auxiliaris (Kühn) Tribe, which cause destroying nematode egg in 6 sites by rate 46.15% from total sites. The suitable pH value for the two species of Chytridiomycetous fungi was ranged from 7.0 to 8.0. C. auxiliaries (Kühn) Tribe was found in 3 soil types. While the fungus C. anguillulae Sorokin was found in 2 soil types.  On the other hand, the organic matters haven’t any effects on the growth of C. auxiliaries (Kühn) Tribe or the ability of parasitism, but they have a great effect on C. anguillulae Sorokin. The present study is considered as preliminary survey on nematode trapping fungi for the first time in province of Khulais and second study on predacious fungi in Saudi Arabian soils. Key word: Ecology, Nematode, trapping fungi, Dactylaria, Catenari

Induced Pluripotent stem cells as a model system to study disease progression in myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are a heterogeneous group of age-associated hematopoietic diseases characterised by abnormal blood cell maturation and a high propensity for leukemic transformation. It is a clonal disease thought to originate in the haematopoietic stem cell (HSC). Therapeutic strategies in high-risk patients include demethylating agents and cytotoxic drugs, however, 50-60% of these patients do not respond to the treatment and progress to the worst stage. Therefore, there is an unmet clinical need to better understand the mechanisms leading to these blood disorders with the ultimate aim to facilitate the development of improved diagnostic and therapeutic strategies. By making use of somatic reprogramming and CRISPR-Cas9 tools, our goal in this study was to generate an in vitro model of low-risk and high-risk MDS that could help to determine the molecular mechanisms leading to disease progression. Peripheral blood mononuclear cells were collected from patient MDS27 when he was diagnosed with low-risk MDS; with cells at this stage harbouring ASLX1, SRSF2 and RUNX1 mutations. These cells were used to generate hiPSC using the non-integrated methods; sendai virus and episomal. Several clones were confirmed to harbour the same somatic mutations as the cells of origin. The pluripotent characteristics of the iPSC clones generated from patient MDS27 as well as from a hiPSC control line were confirmed. Furthermore, the differentiation potential of iPSC into hematopoietic progenitor cells indicated the ability of iPSC to differentiate to hematopoietic stem/progenitor cells (HSPCs) (CD34+ CD43+, CD34+ CD45+). In addition, HSPCs derived from MDS27-iPSC were able to form the different colony-forming unit (CFU) in methylcellulose semi-solid medium with less potential when compared to the hiPSC control. Moreover, the study of the erythroid and myeloid lineage differentiation in liquid cultures indicated that HSPCs derived from MDS27-iPSC could differentiate to such lineages but with aberrant morphology, validating our in vitro system. To generate a model for high-risk MDS, a mutation in C/EBPα causing disruption of the DNA binding domain was generated by CRISPR in the MDS27-iPSC cells, mimicking the additional mutation observed in MDS27 cells when the patient progressed to high-risk MDS. The differentiation of the C/EBPα mutant line (high-risk MDS-iPSC) showed a significant reduction in the myeloid and erythroid colony forming units (CFUs) with a block in granulocytic CFU formation. Furthermore, study of the myeloid lineage indicated that the high-risk MDS-iPSC had an impaired myeloid differentiation due to altered expression of key genes required for myeloid differentiation such as PU.1, GATA2, LMO2 and RUNX1. The study of the erythroid lineage in high-risk MDS27 indicated that the four mutant genes induce erythroid differentiation, increasing the aberrant morphology. Our approach highlights the utility of human iPSCs to understand the molecular mechanisms leading to disease progression and their use as a platform for drug screening which will help to improve diagnostic and therapeutic strategies

Diagnostic radiology and its future:what do clinicians need and think?

Objective: To investigate the view of clinicians on diagnostic radiology and its future. Methods: Corresponding authors who published in the New England Journal of Medicine and the Lancet between 2010 and 2022 were asked to participate in a survey about diagnostic radiology and its future. Results: The 331 participating clinicians gave a median score of 9 on a 0–10 point scale to the value of medical imaging in improving patient-relevant outcomes. 40.6%, 15.1%, 18.9%, and 9.5% of clinicians indicated to interpret more than half of radiography, ultrasonography, CT, and MRI examinations completely by themselves, without consulting a radiologist or reading the radiology report. Two hundred eighty-nine clinicians (87.3%) expected an increase in medical imaging utilization in the coming 10 years, whereas 9 clinicians (2.7%) expected a decrease. The need for diagnostic radiologists in the coming 10 years was expected to increase by 162 clinicians (48.9%), to remain stable by 85 clinicians (25.7%), and to decrease by 47 clinicians (14.2%). Two hundred clinicians (60.4%) expected that artificial intelligence (AI) will not make diagnostic radiologists redundant in the coming 10 years, whereas 54 clinicians (16.3%) thought the opposite. Conclusion: Clinicians who published in the New England Journal of Medicine or the Lancet attribute high value to medical imaging. They generally need radiologists for cross-sectional imaging interpretation, but for a considerable proportion of radiographs, their service is not required. Most expect medical imaging utilization and the need for diagnostic radiologists to increase in the foreseeable future, and do not expect AI to make radiologists redundant. Clinical relevance statement: The views of clinicians on radiology and its future may be used to determine how radiology should be practiced and be further developed. Key Points: • Clinicians generally regard medical imaging as high-value care and expect to use more medical imaging in the future. • Clinicians mainly need radiologists for cross-sectional imaging interpretation while they interpret a substantial proportion of radiographs completely by themselves. • The majority of clinicians expects that the need for diagnostic radiologists will not decrease (half of them even expect that we need more) and does not believe that AI will replace radiologists.</p

Scientific Fraud, Publication Bias, and Honorary Authorship in Nuclear Medicine

Our objective was to investigate nuclear medicine scientists’ experience with scientific fraud, publication bias, and honorary authorship. Methods: Corresponding authors who published an article in one of the 15 general nuclear medicine journals (according to Journal Citation Reports) in 2021 received an invitation to participate in a survey on scientific integrity. Results: In total, 254 (12.4%) of 1,897 corresponding authors completed the survey, of whom 11 (4.3%) admitted to having committed scientific fraud and 54 (21.3%) reported having witnessed or suspected scientific fraud by someone in their department in the past 5 y. Publication bias was considered present by 222 (87.4%) respondents, and honorary authorship practices were experienced by 100 (39.4%) respondents. Respondents assigned a median score of 8 (range, 2–10) on a 1- to 10-point scale for their overall confidence in the integrity of published work. On multivariate analysis, researchers in Asia had significantly more confidence in the integrity of published work, with a b-coefficient of 0.983 (95% CI, 0.512–1.454; P &lt; 0.001). A subset of 22 respondents raised additional concerns, mainly about authorship criteria and assignments, the generally poor quality of published studies, and perverse incentives of journals and publishers. Conclusion: Scientific fraud, publication bias, and honorary authorship appear to be nonnegligible practices in nuclear medicine. Overall confidence in the integrity of published work is high, particularly among researchers in Asia.</p