Recognizing the Product Evolution that Tamed Partial Vacuum Induced Flashovers in 25 kV Class Loadbreak Separable Insulated Connector Systems

2021 ◽  
Author(s):  
David C. Hughes
Keyword(s):  
Product Evolution ◽  
Partial Vacuum

Serous Otitis Media

1973 ◽  
Vol 82 (3) ◽  
pp. 297-301 ◽  
Author(s):  
Robert W. Veltri ◽  
Philip M. Sprinkle
Keyword(s):  
Otitis Media ◽  
Eustachian Tube ◽  
Middle Ear ◽  
Secretory Iga ◽  
Secretory Cells ◽  
Sterile Condition ◽  
Local Synthesis ◽  
Serous Otitis Media ◽  
Inflammatory Insult ◽  
Partial Vacuum

The middle ear fluids of seven patients with bilateral, and five patients with unilateral serous otitis media (SOM), were demonstrated to be microbiologically sterile when assessed for the presence of bacteria, mycoplasma, viruses, and fungi. The concentrations of immunoglobulins G, M, A, D, and lysozyme (muramidase) were determined in the serum and middle ear fluids. Lysozyme levels of middle ear aspirates were found to be elevated in SOM patients. The elevated levels of lysozyme in combination with the antibody-containing classes of immunoglobulins may explain the microbiologically sterile condition of the middle ear fluids of SOM patients. Also, the elevated lysozyme concentrations in middle ear fluids may indicate the previous presence of neutrophils and hence a previous inflammatory insult. The increased levels of IgA demonstrated in middle ear fluids may indicate local synthesis of secretory IgA by secretory cells of Eustachian tube and middle ear. The closed Eustachian tube, partial vacuum conditions and absence of a portal of exit for accumulated serous fluids are offered as a possible explanation for SOM.

A Topic Modeling Approach to Study Design Requirements

2021 ◽  
Author(s):  
Cheng Chen ◽  
Jesse Mullis ◽  
Beshoy Morkos
Keyword(s):  
Domain Knowledge ◽  
Latent Dirichlet Allocation ◽  
High Volume ◽  
Management Tools ◽  
Human Errors ◽  
Domain Experts ◽  
Product Evolution ◽  
Engineering Changes ◽  
Collapsed Gibbs Sampling ◽  
Requirements Documents

Abstract Risk management is vital to a product’s lifecycle. The current practice of reducing risks relies on domain experts or management tools to identify unexpected engineering changes, where such approaches are prone to human errors and laborious operations. However, this study presents a framework to contribute to requirements management by implementing a generative probabilistic model, the supervised latent Dirichlet allocation (LDA) with collapsed Gibbs sampling (CGS), to study the topic composition within three unlabeled and unstructured industrial requirements documents. As finding the preferred number of topics remains an open-ended question, a case study estimates an appropriate number of topics to represent each requirements document based on both perplexity and coherence values. Using human evaluations and interpretable visualizations, the result demonstrates the different level of design details by varying the number of topics. Further, a relevance measurement provides the flexibility to improve the quality of topics. Designers can increase design efficiency by understanding, organizing, and analyzing high-volume requirements documents in confirmation management based on topics across different domains. With domain knowledge and purposeful interpretation of topics, designers can make informed decisions on product evolution and mitigate the risks of unexpected engineering changes.

Kinetics, Product Evolution, and Mechanism for the Pyrolysis of Typical Plastic Waste

2021 ◽  
Author(s):  
Yutao Zhang ◽  
Zegang Fu ◽  
Wei Wang ◽  
Guozhao Ji ◽  
Ming Zhao ◽  
...  
Keyword(s):  
Plastic Waste ◽  
Product Evolution

scholarly journals Low-Temperature Catalytic Pyrolysis of Cellulose in Acidic [Bmim]Otf: A Mechanism Model of Product Evolution

2021 ◽  
Author(s):  
Zhishuncheng Li ◽  
GuangFei Qu ◽  
Yanhua He ◽  
Ping Ning ◽  
Ruosong Xie ◽  
...  
Keyword(s):  
Low Temperature ◽  
Catalytic Pyrolysis ◽  
High Efficiency ◽  
Point Of View ◽  
The Novel ◽  
Catalytic Systems ◽  
Mechanism Model ◽  
Pyrolysis Behavior ◽  
Product Evolution ◽  
The Media

Abstract In this paper, we studied the catalytic pyrolysis behavior of microcrystalline cellulose (MC) in catalytic systems with acidic [Bmim]OTf as the media at temperatures of 140°C, 180°C, 220°C, 260°C, and 300°C. The pyrolysis behavior was investigated via SEM, XRD, FTIR, and GC-MS. During the catalysis of [Bmim]OTf, the pyrolysis temperature of MC was reduced to 140°C significantly and the crystalline structure of MC was destroyed rapidly. The novel synergistic catalytic effect of CF3SO3- and [Bmim]+ was discovered, which may lead to MC-selective cleavage of glycosidic, C-C, C-O, and C-H bonds, accompanied by new bond formation, which showed the production of many small molecular compounds. Furthermore, a novel mechanism model of evolution in [Bmim]OTf at low temperature was developed from a microscopic point of view. This research had obvious significance for the mechanism of directional regulation of target products, finally realizing the high efficiency utilization of biomass.

The naked ape as an evolutionary model, 50 years later

2018 ◽  
Vol 68 (3) ◽  
pp. 227-246
Author(s):  
Nico M. van Straalen
Keyword(s):  
Natural Selection ◽  
Evolutionary Biology ◽  
Evolutionary Model ◽  
Developmental Constraints ◽  
Body Hair ◽  
Product Evolution ◽  
Adaptive Explanation ◽  
History Of ◽  
Popular Texts ◽  
The Brain

AbstractEvolution acts through a combination of four different drivers: (1) mutation, (2) selection, (3) genetic drift, and (4) developmental constraints. There is a tendency among some biologists to frame evolution as the sole result of natural selection, and this tendency is reinforced by many popular texts. “The Naked Ape” by Desmond Morris, published 50 years ago, is no exception. In this paper I argue that evolutionary biology is much richer than natural selection alone. I illustrate this by reconstructing the evolutionary history of five different organs of the human body: foot, pelvis, scrotum, hand and brain. Factors like developmental tinkering, by-product evolution, exaptation and heterochrony are powerful forces for body-plan innovations and the appearance of such innovations in human ancestors does not always require an adaptive explanation. While Morris explained the lack of body hair in the human species by sexual selection, I argue that molecular tinkering of regulatory genes expressed in the brain, followed by positive selection for neotenic features, may have been the driving factor, with loss of body hair as a secondary consequence.

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