scholarly journals Does any convex quadrilateral have circumscribed ellipses?

2017 ◽  
Vol 15 (1) ◽  
pp. 1463-1476
Author(s):  
Jia Hui Li ◽  
Zhuo Qun Wang ◽  
Yi Xi Shen ◽  
Zhong Yuan Dai
Keyword(s):  
Projective Transformation ◽  
Three Dimensional ◽  
Conic Sections ◽  
Coverage Area ◽  
Construction Engineering ◽  
The Past ◽  
Convex Quadrilateral ◽  
Wide Range ◽  
Solid Foundation ◽  
Insight Into

Abstract The past decades have witnessed several well-known beautiful conclusions on four con-cyclic points. With highly promising research value, we profoundly studied circumscribed ellipses of convex quadrilaterals in this paper. Using tools of parallel projective transformation and analytic geometry, we derived several theorems including the proof of the existence of circumscribed ellipses of convex quadrilaterals, the properties of its minimal coverage area, and locus center, respectively. This simple approach lays a solid foundation for its application to three-dimensional situations, which is namely the circumscribed quadric surface of a solid figure and its wide-range utility in construction engineering. Meanwhile, we have a new insight into innate connection of conic sections as well as a taste of beauty and harmony of geometry.

Computer-aided image analysis and graphics in biological microscopy at higher voltages

1991 ◽  
Vol 49 ◽  
pp. 438-439
Author(s):  
B. Carragher ◽  
D. F. Hessler ◽  
J. E. Hinshaw ◽  
M. Martone ◽  
R. A. Milligan ◽  
...  
Keyword(s):  
Biological Sciences ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Molecular Physiology ◽  
The Past ◽  
Software Packages ◽  
Wide Range ◽  
Computer Aided ◽  
Dimensional Reconstruction ◽  
Insight Into

The range of problems accessible to study using high voltage microscopy encompasses structures that span a wide range of dimensions from Angstroms to tens of microns. Structurally oriented cell biologists and neurobiologists examine cells, tissues, organelles and macromolecules in order to gain insight into cellular and molecular physiology by relating structure to function. Comprehension of these structures can be greatly enhanced by the application of computer aided three dimensional reconstruction and analysis techniques.The past decade has seen an explosive growth in the capabilities for the digital acquisition of images. At the same time, the availability of relatively inexpensive graphics workstations and sophisticated image processing and analysis software packages has made graphics and imaging techniques accessible to most research laboratories. However, the complexity of problems studied in the biological sciences has always presented a challenge to the techniques used in the analysis, and methods based on computer graphics are certainly no exception to this rule.

scholarly journals An Insight into Saponins from Quinoa (Chenopodium quinoa Willd): A Review

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1059 ◽  
Author(s):  
Khadija El Hazzam ◽  
Jawhar Hafsa ◽  
Mansour Sobeh ◽  
Manal Mhada ◽  
Moha Taourirte ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Bitter Taste ◽  
Biological Activities ◽  
Chenopodium Quinoa ◽  
Toxic Effects ◽  
Mechanical Abrasion ◽  
Important Group ◽  
The Past ◽  
Wide Range ◽  
Insight Into

Saponins are an important group found in Chenopodium quinoa. They represent an obstacle for the use of quinoa as food for humans and animal feeds because of their bitter taste and toxic effects, which necessitates their elimination. Several saponins elimination methods have been examined to leach the saponins from the quinoa seeds; the wet technique remains the most used at both laboratory and industrial levels. Dry methods (heat treatment, extrusion, roasting, or mechanical abrasion) and genetic methods have also been evaluated. The extraction of quinoa saponins can be carried out by several methods; conventional technologies such as maceration and Soxhlet are the most utilized methods. However, recent research has focused on technologies to improve the efficiency of extraction. At least 40 saponin structures from quinoa have been isolated in the past 30 years, the derived molecular entities essentially being phytolaccagenic, oleanolic and serjanic acids, hederagenin, 3β,23,30 trihydroxy olean-12-en-28-oic acid, 3β-hydroxy-27-oxo-olean-12en-28-oic acid, and 3β,23,30 trihydroxy olean-12-en-28-oic acid. These metabolites exhibit a wide range of biological activities, such as molluscicidal, antifungal, anti-inflammatory, hemolytic, and cytotoxic properties.

scholarly journals Archaeometry’s Role in Cultural Heritage Sustainability and Development

2019 ◽  
Vol 11 (7) ◽  
pp. 1972 ◽  
Author(s):  
Ioannis Liritzis ◽  
Elena Korka
Keyword(s):  
Cultural Heritage ◽  
New Technologies ◽  
Three Dimensional ◽  
Significant Information ◽  
Academic Field ◽  
The Past ◽  
Interdisciplinary Field ◽  
Wide Range ◽  
Archaeological Materials ◽  
Cultural Legacies

The interdisciplinary field of archaeometry covers a wide range of subject categories and disciplines in relation to science and humanities. It is a well-established academic field of study and accredited part of higher education. Since its inception, the nomenclature designation of archaeometry signifies the appropriate methodology applied to archaeological materials and questions emerging from this field, regarding monuments, artifacts, and the reconstruction and management of landscape bearing cultural assets. The measurements of tangible culture denote significant information, such as chronology, authenticity, technology, characterization, provenance, discovering buried antiquities, ancient-day life activities, and three-dimensional (3D) reconstructions and modelling; furthermore, proxy data collected from environmental dynamic non-liner perturbations, which link local ecosystems with dwellings, are gathered by academia to study the past. The traditional rooting signifies the cultural legacies of people, which define the human desire and the confidence of memory and future trends. Beyond the mere study of the past, archaeometry’s role increasingly proves affinity to prosperity, if properly managed. The major archaeometrical contributions in cultural heritage and archaeology in general are reviewed herein, and we present the policies that could develop archaeometrical data into a sustainable stage of local, regional, and national economic development. Τhe United Nations Educational, Scientific, and Cultural Organization (UNESCO) conventions for the documentation and protection of cultural heritage via new technologies and archaeometry are reviewed and connected to development strategies and sustainable development goals.

scholarly journals Evaluating species in Botryosphaeriales

2021 ◽  
Author(s):  
W. Zhang ◽  
J.Z. Groenewald ◽  
L. Lombard ◽  
R.K. Schumacher ◽  
A.J.L. Phillips ◽  
...  
Keyword(s):  
South Africa ◽  
Woody Plants ◽  
Phylogenetic Analyses ◽  
Culture Collection ◽  
Morphological Data ◽  
Culture Collections ◽  
Future Studies ◽  
The Past ◽  
Wide Range ◽  
Solid Foundation

The Botryosphaeriales (Dothideomycetes) includes numerous endophytic, saprobic, and plant pathogenic species associated with a wide range of symptoms, most commonly on woody plants. In a recent phylogenetic treatment of 499 isolates in the culture collection (CBS) of the Westerdijk Institute, we evaluated the families and genera accommodated in this order of important fungi. The present study presents multigene phylogenetic analyses for an additional 230 isolates, using ITS, tef1, tub2, LSU and rpb2 loci, in combination with morphological data. Based on these data, 58 species are reduced to synonymy, and eight novel species are described. They include Diplodia afrocarpi (Afrocarpus, South Africa), Dothiorella diospyricola (Diospyros, South Africa), Lasiodiplodia acaciae (Acacia, Indonesia), Neofusicoccum podocarpi (Podocarpus, South Africa), N. rapaneae (Rapanea, South Africa), Phaeobotryon ulmi (Ulmus, Germany), Saccharata grevilleae (Grevillea, Australia) and S. hakeiphila (Hakea, Australia). The results have clarified the identity of numerous isolates that lacked Latin binomials or had been deposited under incorrect names in the CBS collection in the past. They also provide a solid foundation for more in-depth future studies on taxa in the order. Sequences of the tef1, tub2 and rpb2 genes proved to be the most reliable markers. At the species level, results showed that the most informative genes were inconsistent, but that a combination of four candidate barcodes (ITS, tef1, tub2 and rpb2) provided reliable resolution. Furthermore, given the large number of additional isolates included in this study, and newly generated multigene DNA datasets, several species could also be reduced to synonymy. The study illustrates the value of reassessing the identity of older collections in culture collections utilising modern taxonomic frameworks and methods.

New insight into the preparation of flame-retardant thermoplastic polyether ester utilizing β-cyclodextrin as a charring agent

2016 ◽  
Vol 29 (4) ◽  
pp. 422-430 ◽  
Author(s):  
Luchong Zhang ◽  
Wei Wu ◽  
Jia Hui Li ◽  
Zheng Wang ◽  
Liang Wang ◽  
...  
Keyword(s):  
Flame Retardants ◽  
Testing Machine ◽  
Laser Raman Spectroscopy ◽  
Limiting Oxygen Index ◽  
Laser Raman ◽  
The Past ◽  
Charring Agent ◽  
Wide Range ◽  
Insight Into ◽  
Remarkable Progress

The past decade has witnessed remarkable progress of the development and amelioration of thermoplastic polyether ester elastomer (TPEE), showing its promising wide-range utility. Herein we unraveled an unprecedented research to utilize β-cyclodextrin (β-CD) with perfect charring ability in TPEE in substitution of toxic halogen flame retardants. The TPEE/phosphorous–nitrogen flame retardants (P-N FR) (aluminum diethylphosphinate and melamine polyphosphate)/β-CD system was created and the flame retardance effects were determined using the limiting oxygen index (LOI) and the vertical burning test (UL94), while the charring effects of β-CD were measured by thermogravimetric analysis (TGA), laser Raman spectroscopy (LRS), and scanning electron microscopy (SEM). Besides, the mechanical properties and the morphology were tested by the universal testing machine and SEM. Results indicate that with 10 wt% of β-CD added to the TPEE/25 wt% P-N FR systems, the UL94 can reach to V-0 grade and the tensile strength of this blend was kept above 10 MPa, which can be applied in practice. To our delight, β-CD promoted the formation of stable and compact carbonaceous char, preventing the melt dripping and enhancing the properties and the charring mechanism was better studied by real-time Fourier transform infrared spectra. Being easy to construct, sustainable, and economic, the TPEE composite modified by β-CD and P-N FR is a reliable and widely applicable novel fire retardation material.

Figuring the Group

2011 ◽  
Vol 21 (2) ◽  
pp. 165-186 ◽  
Author(s):  
Elizabeth DeMarrais
Keyword(s):  
Group Dynamics ◽  
Social Group ◽  
Rock Art ◽  
Three Dimensional ◽  
Emotional Experiences ◽  
The Past ◽  
Group Life ◽  
The Social ◽  
Wide Range ◽  
Collective Experience

This article focuses on the social group, asking how approaches to the representation of the group (in forms such as rock-art, images painted on pottery and three-dimensional caches of figurines) can help us understand the nature of collective experience in the past. Current research has concentrated on individuals (and their experiences) in past societies, while group dynamics have been neglected. Attention should be re-directed to the wide range of emotional experiences that we know affected individuals, particularly as part of their interactions with others, during rituals and other collective events in the past. Investigation of figurative representations over a sustained period provides one means of reconstructing the repetitive, stereotyped emotions, local rules, ‘non-rational’ propensities, moral sentiments, and shared emotions that shaped group life in past societies.

scholarly journals Antigen-Specific Treatment Modalities in MS: The Past, the Present, and the Future

2021 ◽  
Vol 12 ◽  
Author(s):  
Judith Derdelinckx ◽  
Patrick Cras ◽  
Zwi N. Berneman ◽  
Nathalie Cools
Keyword(s):  
Multiple Sclerosis ◽  
Treatment Strategies ◽  
Specific Treatment ◽  
Clinical Development ◽  
Treatment Modalities ◽  
Specific Therapy ◽  
The Past ◽  
Wide Range ◽  
Multiple Sclerosis Patients ◽  
Insight Into

Antigen-specific therapy for multiple sclerosis may lead to a more effective therapy by induction of tolerance to a wide range of myelin-derived antigens without hampering the normal surveillance and effector function of the immune system. Numerous attempts to restore tolerance toward myelin-derived antigens have been made over the past decades, both in animal models of multiple sclerosis and in clinical trials for multiple sclerosis patients. In this review, we will give an overview of the current approaches for antigen-specific therapy that are in clinical development for multiple sclerosis as well provide an insight into the challenges for future antigen-specific treatment strategies for multiple sclerosis.

Post-1990 Documentary

2015 ◽  
Keyword(s):  
Film Industry ◽  
Political Systems ◽  
Traditional Media ◽  
The Past ◽  
Wide Range ◽  
Production Distribution ◽  
Global Understanding ◽  
Exhibition Strategies ◽  
Insight Into ◽  
Made In

This book presents in-depth case studies focusing on the major aspects of post-1990 documentary practices and styles. The book questions the meanings of ‘independence’ for documentaries made in the post-1990 context, a period of unrivalled disruption and creativity in the field. Written from a wide range of academic perspectives, the book sheds new light on historical, theoretical, and empirical issues pertaining to the independent documentary, in order to better comprehend the radical transformations of the form over the past twenty years. The book focuses on works and practitioners existing at the margins of the traditional media, the mainstream film industry, and the prevailing economic and socio-political systems. In doing so, it addresses an important gap in the global understanding of documentary practices and styles. The book provides critical and detailed insight into contemporary independent documentary makers and their varied works, practices and uses and offers a variety of perspectives and interpretations of under studied contemporary subject matters and styles, as well as production, distribution, and exhibition strategies.

scholarly journals Ship-Source Spills – it's More Than Just Oil

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Lauren Fear ◽  
Duarte Soares
Keyword(s):  
Oil Spills ◽  
Environmental Damage ◽  
Shipping Industry ◽  
The Past ◽  
Changing Trends ◽  
Sustained Reduction ◽  
Wide Range ◽  
Key Issues ◽  
Recent Trends ◽  
Insight Into

Abstract For over 50 years, ITOPF has attended on-site at marine spills worldwide on behalf of the shipping industry. ITOPF staff have provided objective technical advice at over 800 incidents in 100 countries, gaining unparalleled insight into changing trends in ship-source pollution. Spills of oil were originally the focus of ITOPF's activities, initially from tankers and later from a wide range of ships. Over time, there has been a dramatic and sustained reduction in both the number of oil spills and the quantity of oil spilt from tankers, as ITOPF's statistics demonstrate. Though spills of oil cargoes and bunker fuel remain at the core of ITOPF's work, its activities have expanded in recent years to include other pollutants, such as vegetable oils, hazardous and non-hazardous chemicals, coal, foodstuffs, plastics and the myriad of other products transported in container ships. Almost two thirds of the incidents ITOPF attends now involve non-tankers and in the past 20 years, 14% of all attended incident involved products or substances other than, or in addition to, oil. Oil spill events can cause environmental damage and typically attract considerable media attention. However, other marine pollutants also have the potential to cause environmental damage and pose significant challenges for responders. This paper draws on ITOPF's first-hand experience to examine some of the recent trends in spill response, using case histories to highlight key issues involved with the response of spills of assorted oils and cargoes at sea.

scholarly journals THREE-DIMENSIONAL NUMERICAL MODELING OF SEDIMENT TRANSPORT NEAR COASTAL INLETS

2018 ◽  
pp. 32
Author(s):  
Weiming Wu
Keyword(s):  
Numerical Modeling ◽  
Sediment Transport ◽  
Three Dimensional ◽  
Density Currents ◽  
Complex Flow ◽  
Spatial And Temporal Scales ◽  
The Past ◽  
Wide Range ◽  
Coastal Inlets ◽  
D Model

Simulation of the hydro- and morphodynamic processes near coastal inlets is important but challenging, due to multiple interacting forces (waves, wind, tides, river flows, density currents, etc.) on a wide range of spatial and temporal scales. A number of 2-D models have been used in the past, but recently 3-D models have gained more and more attentions because better accuracy and reliability are desired. A 3-D model has been developed in this study to simulate the complex flow, sediment transport and bed change near coastal inlets.

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