Analyzing Burner Performance and Combustion Phenomenon in an Olefin Plant's Industrial Furnace: A CFD Study.

This work presents a comprehensive study of the combustion performance of an industrial furnace in an olefin plant using computational fluid dynamics (CFD) simulations. The focus was on analyzing the heat release pattern of bottom burners to optimize the furnace efficiency in steam-cracking processes. The study developed an accurate computational fluid dynamics (CFD) model for predicting combustion behavior in a cracking furnace. The computational model was validated by comparing the simulation results with industrial data and was used to investigate the impact of burner clogging and the importance of small holes in the body of burners in the furnace. The results also provided insights into the influence of excess air, temperature distribution, fluid behavior, composition of combustion products, and thermal efficiency of the furnace. The presented results contributed to a better understanding of parameters controlling combustion performance in steam-cracking furnaces.

Real-Time Detection of Incipient Inter-Turn Short Circuit and Sensor Faults in Permanent Magnet Synchronous Motor Drives Based on Generalized Likelihood Ratio Test and Structural Analysis.

This paper presents a robust model-based technique to detect multiple faults in permanent magnet synchronous motors (PMSMs), namely inter-turn short circuit (ITSC) and encoder faults. The proposed model is based on a structural analysis, which uses the dynamic mathematical model of a PMSM in an abc frame to evaluate the system's structural model in matrix form. The just-determined and over-determined parts of the system are separated by a Dulmage-Mendelsohn decomposition tool. Subsequently, the analytical redundant relations obtained using the over-determined part of the system are used to form smaller redundant testable sub-models based on the number of defined fault terms. Furthermore, four structured residuals are designed based on the acquired redundant sub-models to detect measurement faults in the encoder and ITSC faults, which are applied in different levels of each phase winding. The effectiveness of the proposed detection method is validated by an in-house test setup of an inverter-fed PMSM, where ITSC and encoder faults are applied to the system in different time intervals using controllable relays. Finally, a statistical detector, namely a generalized likelihood ratio test algorithm, is implemented in the decision-making diagnostic system resulting in the ability to detect ITSC faults as small as one single short-circuited turn out of 102, i.e., when less than 1% of the PMSM phase winding is short-circuited.

Design and Optimization of Cationic Nanocapsules for Topical Delivery of Tretinoin: Application of the Box-Behnken Design, In Vitro Evaluation, and Ex Vivo Skin Deposition Study.

Cationic nanocapsules represent a promising approach for topical delivery purposes. We elaborated on a novel formulation based on the cationic nanocapsules to enhance the pharmacodynamic efficacy, user compliance, and photostability of tretinoin (TTN). To achieve this goal, TTN nanocapsules were prepared by the nanoprecipitation method. In order to statistically optimize formulation variables, a Box-Behnken design, using Design-Expert software, was employed. Three independent variables were evaluated: total weight of the cationic acrylic polymer (X 1), oil volume (X 2), and TTN amount (X 3). The particle size and encapsulation efficiency percent (EE%) were selected as dependent variables. The optimal formulation demonstrated spherical morphology under scanning electron microscopy (SEM), optimum particle size of 116.3 nm, and high EE% of 83.2%. TTN-loaded nanocapsules improved photostability compared to its methanolic solution. The in vitro release study data showed that tretinoin was released in a sustained manner compared to the free drug. The ex vivo skin permeation study demonstrated that greater drug deposition into the epidermal region rather than the deep skin was observed with a gel containing TTN-loaded nanocapsules than that of drug solution, respectively. The skin irritation test revealed that the nanoencapsulation of the drug decreased its irritancy compared to the free drug. These results revealed the promising potential of cationic nanocapsules for topical delivery of tretinoin.

Ancient cattle genomics, origins, and rapid turnover in the Fertile Crescent.

Genome-wide analysis of 67 ancient Near Eastern cattle, Bos taurus, remains reveals regional variation that has since been obscured by admixture in modern populations. Comparisons of genomes of early domestic cattle to their aurochs progenitors identify diverse origins with separate introgressions of wild stock. A later region-wide Bronze Age shift indicates rapid and widespread introgression of zebu, Bos indicus, from the Indus Valley. This process was likely stimulated at the onset of the current geological age, ~4.2 thousand years ago, by a widespread multicentury drought. In contrast to genome-wide admixture, mitochondrial DNA stasis supports that this introgression was male-driven, suggesting that selection of arid-adapted zebu bulls enhanced herd survival. This human-mediated migration of zebu-derived genetics has continued through millennia, altering tropical herding on each continent.

Evaluation of the Effects of Charged Amino Acids on Uncontrolled Seizures.

Introduction. Epilepsy is one of the most common diseases of the central nervous system. The prevalence of epilepsy throughout the world is 0.5 to 1%, and the same rate is 7.8 per 1000 in Kerman. Almost 20 to 30% of epileptic patients do not respond properly to common medications. The present study investigated patients who did not respond to common and, even in some cases, adjuvant therapies, with two seizures or more per week, regardless of the type of the inflicted epilepsy. Methodology. The participants of the present double-blind study were randomly selected into three 10-member groups of uncontrolled epileptic patients (arginine, glutamic acid, and lysine). The patients used amino acid powder dissolved in water (three times the daily need) every day for two weeks before breakfast. The number of seizures was recorded one week prior to commencing amino acid use, as well as the first and the second weeks subsequent to use. Results. A total of 32 patients were studied in three groups. The decline rates of seizures were 53%, 41%, and 13%, and the P value was 0.013, 0.027, and 0.720, respectively. Conclusion. Administration of the charged amino acids, arginine, and glutamic acid can decrease the seizures of patients suffering from uncontrolled epilepsy.

Topical captopril as a novel agent against hypertrophic scar formation in new zealand white rabbit skin.

Collagen constitutes the majority of extracellular matrix in tissues such as bone, cartilage, and especially the skin. Over production and/or decreased degradation of collagen fibers could lead to an abnormal wound healing response resulting in hypertrophic scarring or keloid formation. Recently, angiotensin II has been shown to be present in several cutaneous cells and that it stimulates fibroblast proliferation, collagen synthesis, and suppresses matrix metalloproteinase activity. The following study examines the effect of topical captopril, an inhibitor of angiotensin II production, against hypertrophic scar formation in New Zealand white rabbits.Two dermal wounds were made over the ventral surface of the ears of each rabbit (n = 6). In each animal, separate wounds were treated once per day with either topical 5% captopril or the vehicle alone (70% ethanol and 30% propylene glycol) for 7 consecutive days. Wounds were harvested at postoperative day 28, and the scar elevation index (SEI) as well as collagen organization was evaluated. SEI was reduced from 3.06 in the vehicle-treated group to 1.94 in the captopril treated wounds (P < 0.05). However, an increase in collagen organization was achieved by captopril, while an 8.50% decrease in collagen organization scale was derived by captopril compared to the vehicle. Results of this study show, for the first time, the efficacy of topical captopril as a new agent for the prevention of hypertrophic scar formation in an animal model. Thus, captopril might represent the first angiotensin converting enzyme inhibitor with a novel pharmacologic application in dermatology.

Retinoic acid synergistically enhances the melanocytotoxic and depigmenting effects of monobenzylether of hydroquinone in black guinea pig skin.

Monobenzylether of hydroquinone (MBEH) has long been utilized for the depigmentation therapy of patients with extensive vitiligo. In this approach, the normally pigmented areas surrounding vitiligo lesions are depigmented to achieve a uniform skin tone. One of the important disadvantages of MBEH therapy, however, is the resistance of a considerable number of vitiligo patients against the depigmenting effect of this agent. We have previously proposed that the glutathione-dependent cytoprotection of melanocytes can be impaired through the inhibition of the enzyme glutathione S-transferase by retinoic acid (RA). The combination of RA with melanocytotoxic agents could thus lead to increased susceptibility of melanocytes to such compounds. In this study we have shown, for the first time, that the melanocytotoxic and depigmenting effects of MBEH are synergistically enhanced when it is combined with RA. The treatment of black guinea pig skin with RA (0.025%) alone induced no significant changes in the number of epidermal melanocytes and no skin depigmentation. On the other hand, MBEH (10%) produced mild to moderate skin depigmentation and reduced the average number of melanocytes from 76 (+/-5)/field (magnification: x 40) in control sites, to 42 (+/-6)/field in the depigmented skin. The RA (0.025%)-MBEH (10%) combination, however, produced a complete degree of depigmentation in the majority of treated sites after 10 days of application and reduced the average number of melanocytes to only 6 (+/-6)/field. RA-MBEH combination serves as a very potent skin depigmenting formula and now awaits future assessments of its potential use for the treatment of extensive vitiligo.