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旋转声黑洞圆盘建模与分析

旋转声黑洞圆盘建模与分析

Machine Learning Based Virtual Screening for Biodegradable Polyesters

第十四届全国振动理论及应用学术会议(NVTA2021)

作者：朱润泽 navya bojja 秦朝烨褚福磊清华大学机械工程系

利用声黑洞(ABH)进行薄壁结构的振动抑制在近年来受到了非常广泛的关注。但目前关于ABH的文献均针对静止结构,尚无有关ABH在旋转结构上应用的研究。为弥补这一空白,本文提出了一种针对旋转ABH圆盘的建模方法。首先,利用Kirchhoff薄板理... 详细信息

利用声黑洞(ABH)进行薄壁结构的振动抑制在近年来受到了非常广泛的关注。但目前关于ABH的文献均针对静止结构,尚无有关ABH在旋转结构上应用的研究。为弥补这一空白,本文提出了一种针对旋转ABH圆盘的建模方法。首先,利用Kirchhoff薄板理论和Raleigh-Ritz法得到了系统的动力学方程,通过与有限元仿真结果的对比,验证了所提模型的准确性。随后,针对非旋转和旋转情况,利用所提模型进行了自由振动和强迫振动分析。结果表明,在非旋转条件下,ABH结构具有较好的减振效果;在旋转条件下,ABH仍能在一定程度上实现对圆盘的振动抑制,但转速和激励形式会影响其抑振效果。

关键词：声黑洞旋转盘 Raleigh-Ritz法振动抑制

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Journal of Materials Science and Chemical Engineering 2024年第8期12卷 1-11页

作者： navya Nori Milton High School Milton USA

Current biodegradation timelines show that polyesters take over 200 years to break down. A crucial component of several industries, polyesters are relied upon for materials development and thus require sustainable alternatives. Recent works in generative modeling have made it possible to produce large sets of chemical structures, but current molecular screening methods are expensive, not scalable, and are oversimplified. This work evaluates whether a molecule’s biodegradability potential can be accurately predicted by training a model on recent experimental data. Additionally, three chemical descriptors were evaluated on the final molecules for their effects on biodegradability: molecular structure, bond types, and solubility. A Gradient Boosted Machine was trained on a dataset of 600 molecules and their binary labels on biodegradability. The classification model effectively captured the biodegradability property, yielding an Area Under the Receiver Operating Characteristics, AUROC, of 84% and an Area Under the Precision Recall Curve, or AUPRC, of 87%. Additionally, an existing amortized synthetic tree generation model, SynNet, validated each molecule by showing chemical synthesizability and producing simple and interpretable synthesis pathways. This approach of filtering by prediction and chemical rule interpretation is inexpensive, highly scalable and can capture the necessary complexity. Using this method, novel polyester candidates can be polymerized and produced into sustainable fabrics, reducing environmental stress from textile-reliant industries.

关键词： Biodegradability Molecular Generation Virtual Screening

Hyperkalemia:Major but still understudied complication among heart transplant recipients

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World Journal of Transplantation 2021年第6期11卷 203-211页

作者： Jagmeet Singh Asim Kichloo navya Vipparla Michael Aljadah Michael Albosta Shakeel Jamal Sindhura Ananthaneni Sandesh Parajuli Department of Nephrology Guthrie Robert Packer HospitalSayrePA 18840United States Department of Internal Medicine Central Michigan University College of MedicineSaginawMI 48602United States Department of Internal Medicine Medical College of WisconsinMilwaukeeWI 53226United States Department of Nephrology University of Wisconsin School of Medicine and Public HealthMadisonWI 53706United States

Hyperkalemia is a recognized and potentially life-threatening complication ofheart transplantation. In the complex biosystem created by transplantation,recipients are susceptible to multiple mechanisms for hyperkalemia which arediscussed in detail in this manuscript. Hyperkalemia in heart transplantationcould occur pre-transplant, during the transplant period, or post-transplant. Pretransplantcauses of hyperkalemia include hypothermia, donor heart preservationsolutions, conventional cardioplegia, normokalemic cardioplegia, continuouswarm reperfusion technique, and ex-vivo heart perfusion. Intra-transplant causesof hyperkalemia include anesthetic medications used during the procedure,heparinization, blood transfusions, and a low output state. Finally, post-transplantcauses of hyperkalemia include hemostasis and drug-induced *** has been studied in kidney and liver transplant recipients, butthere is limited data on the incidence, causes, management, and prevention inheart transplant recipients. Hyperkalemia is associated with an increased risk ofhospital mortality and readmission in these patients. This review describes thecurrent literature pertaining to the causes, pathophysiology, and treatment ofhyperkalemia in patients undergoing heart transplantation and focuses primarilyon post-heart transplantation.

关键词： Transplantation Cardiovascular Hyperkalemia Heart transplant Medication Management

Purification and Characterisation of a Coffee Pulp Tannase Produced by Penicillium verrucosum

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Journal of Food Science and Engineering 2013年第6期3卷 323-331页

作者： Roopali N. Bhoite navya P. N Pushpa S. Murthy Plantation Products Spices & Flavour Technology Department Central Food .Technological Research Institute Council of Scientificand Industrial Research New Delhi India

Tannase was extracted from a new fungal strain Penicillium verrucosum using coffee pulp as a substrate by solid state fermentation. The extracellular tannase was purified using Sephadex G-100 to 86.02 folds with 34.3% yield and a single band corresponding to 81 kDa was observed in SDS-PAGE. Tannase was immobilized on alginate by entrapment method. The graphical analysis of the effect of the substrate concentration on the tannase activity yielded a Km of 48.88 mM and a Vmax of 169.49 U/mL. The optimum temperature and pH of the enzyme were 30 ℃ and pH 5. The thermal stability, as well as stability over a wide range ofpH, was significantly improved by the immobilization process. The activity was enhanced by Mg^2＋（23.5%） and K^＋（5.3%）, whereas Zn^2＋, Cu^2＋, Ca^2＋, NH^4＋ and Hg^2＋ inhibited tannase activity. Maximum substrate bioconversion （58.94%） from tannic acid to gallic acid and tea cream solubilisation （32.82%） was achieved using immobilized tannase. The extracellular tannase produced by P. verrucosum showed distinctive characteristics such as monomeric structure and activation by Mg^2＋, suggesting a new kind of fungal tannase with biotechnological potential.

关键词： Tannase Penicillium verrucosum solid state fermentation purification characterization immobilization.

Joining of AZ31 and AZ91 Mg alloys by friction stir welding

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Journal of Magnesium and Alloys 2015年第4期3卷 330-334页

作者： B.Ratna Sunil G.Pradeep Kumar Reddy A.S.N.Mounika P.navya Sree P.Rama Pinneswari I.Ambica R.Ajay Babu P.Amarnadh Department of Mechanical Engineering Rajiv Gandhi University of Knowledge Technologies(AP-IIIT)Nuzvid 521202India Department of Mechanical Engineering Vignana Bharathi Institute of TechnologyHyderabad 501301India

Two dissimilar magnesium(Mg)alloy sheets,one with low aluminium(AZ31)and another with high aluminium(AZ91)content,were successfully joined by friction stir welding(FSW).The effect of process parameters on the formation of hot cracks was investigated.A sound metallurgical joint was obtained at optimized process parameters(1400 rpm with 25 mm/min feed)which contained fine grains and distributed β(Mg_(17)Al_(12))phase within the nugget *** increasing trend in the hardness measurements has also confirmed more amount of dissolution of aluminium within the nugget zone.A sharp interface between nugget zone and thermo mechanical affected zone(TMAZ)was clearly noticed at the AZ31 Mg alloy side(advancing)but not on the AZ91 Mg alloy side(retreating).From the results it can be concluded that FSW can be effectively used to join dissimilar metals,particularly difficult to process metals such as Mg alloys,and hot cracking can be completely eliminated by choosing appropriate process parameters to achieve sound joint.

关键词： Dissimilar metal joining Magnesium alloys Friction stir welding AZ31 AZ91