Design and Characterization of Novel Dirhodium Coordination Polymers - The Impact of Ligand Size on Selectivity in Asymmetric Cyclopropanation

2021 ◽  
Author(s):  
Zhenzhong Li ◽  
Lorenz Roesler ◽  
Till Wissel ◽  
Hergen Breitzke ◽  
Kathrin Hofmann ◽  
...  
Keyword(s):  
Coordination Polymers ◽  
Ligand Exchange ◽  
Dicarboxylic Acids ◽  
Sem Images ◽  
Asymmetric Cyclopropanation ◽  
The Impact

Three chiral dirhodium coordination polymers Rh2-Ln (n=1-3) have been synthesized via ligand exchange between dirhodium trifluoroacetate Rh2(TFA)4 and differently sized chiral dicarboxylic acids derived from L-tert-leucine. SEM images indicate that...

scholarly journals Production and Characterization of Amorphous Aluminum-Copper Alloy for Aerospace Applications

2017 ◽  
Vol 2 (2) ◽  
pp. 1 ◽  
Author(s):  
Olayide R. Adetunji ◽  
Muyiwa L. Olukuade ◽  
Wojciech Simka ◽  
Maciej Sowa ◽  
Olanrewaju Moses Adesusi ◽  
...  
Keyword(s):  
Impact Toughness ◽  
Glassy Alloy ◽  
Control Sample ◽  
High Strength ◽  
Sem Images ◽  
Aerospace Applications ◽  
Cu Alloy ◽  
Aluminium Copper ◽  
The Impact

The main objective of this research is to produce and characterize amorphous Aluminium copper (Cu) alloy for high strength applications. High grade of both Aluminium and copper ingots were charged to a ceramic mould and put in an electric furnace in the ratio of 13:1 of Al and Cu respectively. The furnace temperature was set at 1300oC and after melting, ingot casting was done using plastic mould with sprayed water to achieve rapid cooling. An amorphous metal or glassy structure was produced from the ingot by super cooling through preheating the cast rod to 600oC and rapid cooled by water quenching. The glassy alloy rods and Al control sample were prepared for Scanning Electron Microscope (SEM), tensile and impact toughness characterizations. The results showed SEM images of the Al-Cu alloy and pure Al samples. The ultimate tensile strengths for Al-Cu and Al samples were 399 and 330 kg/m2 respectively. Similarly, the impact strengths obtained were 27.3 and 26.4 J. It can be concluded that glassy phase Al-Cu alloy was produced with high ultimate tensile strength and impact toughness. The amorphous alloy produced is a good structural material for aerospace applications. 

scholarly journals Physical and Structural Characterization of Underutilized Climate-Resilient Seed Grains: Millets, Sorghum, and Amaranth

2021 ◽  
Vol 5 ◽  
Author(s):  
Sarah Geisen ◽  
Kiruba Krishnaswamy ◽  
Rob Myers
Keyword(s):  
Food Processing ◽  
Surface Characteristics ◽  
Angle Of Repose ◽  
Healthy Foods ◽  
Underutilized Crops ◽  
Sem Images ◽  
Processing Technologies ◽  
Loss And Damage ◽  
The Impact

While the world is facing food and nutritional challenges leading to the multifaceted burden of malnutrition (underweight and overweight), there is a need to sustainably diversify and explore underutilized crops. Climate-resilient crops, which have the potential to withstand climate crises, have drought resistance, and provide healthy foods with essential vitamins and minerals. Ancient seed grains like amaranth, millets, and sorghum are highly nutritious seed grains that are underutilized, and there is a need for comprehensive research into their properties. This study will specifically investigate amaranth alongside barnyard, finger, kodo, little, pearl, proso millets, and sorghum. Physical and structural properties of the ancient seed grains can provide useful data for storage and food processing. The angle of repose, porosity, and water activity of the grains varied from 19.3° to 23.9°, 3.6 to 17.4%, and 0.533 to 0.660 at 25.5°C, respectively. Additionally, Scanning Electron Microscopy (SEM) was used to observe the surface characteristics and overall shape of each grain. SEM images of the millets shows the impact of dehulling on the surface morphology of the grains (little, barnyard, proso, and kodo millets). This calls for research and development of novel food processing technologies to minimize loss and damage during processing of climate-resilient crops.

The Analyses of Learning Strategies in English as a Second Language: Theoretical Classification and Measurement Test

2020 ◽  
Vol 4 (2) ◽  
pp. 118-129
Author(s):  
Asti Gumartifa ◽  
◽  
Indah Windra Dwie Agustiani
Keyword(s):  
Language Learning ◽  
Learning Outcomes ◽  
Learning Strategies ◽  
Learning Process ◽  
English Learners ◽  
English Language ◽  
Point Of View ◽  
Effective Learning ◽  
The Impact

Gaining English language learning effectively has been discussed all years long. Similarly, Learners have various troubles outcomes in the learning process. Creating a joyful and comfortable situation must be considered by learners. Thus, the implementation of effective learning strategies is certainly necessary for English learners. This descriptive study has two purposes: first, to introduce the classification and characterization of learning strategies such as; memory, cognitive, metacognitive, compensation, social, and affective strategies that are used by learners in the classroom and second, it provides some questionnaires item based on Strategy of Inventory for Language Learning (SILL) version 5.0 that can be used to examine the frequency of students’ learning strategies in the learning process. The summary of this study explains and discusses the researchers’ point of view on the impact of learning outcomes by learning strategies used. Finally, utilizing appropriate learning strategies are certainly beneficial for both teachers and learners to achieve the learning target effectively.

scholarly journals Modulation of Gut Microbiota and Oxidative Status by β-Carotene in Late Pregnant Sows

2020 ◽  
Vol 7 ◽  
Author(s):  
Xupeng Yuan ◽  
Jiahao Yan ◽  
Ruizhi Hu ◽  
Yanli Li ◽  
Ying Wang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Dietary Supplementation ◽  
Basal Diet ◽  
Fecal Microbiota ◽  
Control Group ◽  
Metabolic Activities ◽  
The Impact ◽  
Positive Effect ◽  
Β Carotene

Recent evidences suggest that gut microbiota plays an important role in regulating physiological and metabolic activities of pregnant sows, and β-carotene has a potentially positive effect on reproduction, but the impact of β-carotene on gut microbiota in pregnant sows remains unknown. This study aimed to explore the effect and mechanisms of β-carotene on the reproductive performance of sows from the aspect of gut microbiota. A total of 48 hybrid pregnant sows (Landrace × Yorkshire) with similar parity were randomly allocated into three groups (n = 16) and fed with a basal diet or a diet containing 30 or 90 mg/kg of β-carotene from day 90 of gestation until parturition. Dietary supplementation of 30 or 90 mg/kg β-carotene increased the number of live birth to 11.82 ± 1.54 and 12.29 ± 2.09, respectively, while the control group was 11.00 ± 1.41 (P = 0.201). Moreover, β-carotene increased significantly the serum nitric oxide (NO) level and glutathione peroxidase (GSH-Px) activity (P < 0.05). Characterization of fecal microbiota revealed that 90 mg/kg β-carotene increased the diversity of the gut flora (P < 0.05). In particular, β-carotene decreased the relative abundance of Firmicutes including Lachnospiraceae AC2044 group, Lachnospiraceae NK4B4 group and Ruminococcaceae UCG-008, but enriched Proteobacteria including Bilophila and Sutterella, and Actinobacteria including Corynebacterium and Corynebacterium 1 which are related to NO synthesis. These data demonstrated that dietary supplementation of β-carotene may increase antioxidant enzyme activity and NO, an important vasodilator to promote the neonatal blood circulation, through regulating gut microbiota in sows.

scholarly journals Clonal approaches to understanding the impact of mutations on hematologic disease development

Blood ◽  
2019 ◽  
Vol 133 (13) ◽  
pp. 1436-1445 ◽  
Author(s):  
Jyoti Nangalia ◽  
Emily Mitchell ◽  
Anthony R. Green
Keyword(s):  
Somatic Mutations ◽  
Clonal Selection ◽  
Single Cells ◽  
Driver Mutations ◽  
Great Promise ◽  
Tumor Evolution ◽  
Disease Development ◽  
Hematopoietic Tissue ◽  
The Impact

Abstract Interrogation of hematopoietic tissue at the clonal level has a rich history spanning over 50 years, and has provided critical insights into both normal and malignant hematopoiesis. Characterization of chromosomes identified some of the first genetic links to cancer with the discovery of chromosomal translocations in association with many hematological neoplasms. The unique accessibility of hematopoietic tissue and the ability to clonally expand hematopoietic progenitors in vitro has provided fundamental insights into the cellular hierarchy of normal hematopoiesis, as well as the functional impact of driver mutations in disease. Transplantation assays in murine models have enabled cellular assessment of the functional consequences of somatic mutations in vivo. Most recently, next-generation sequencing–based assays have shown great promise in allowing multi-“omic” characterization of single cells. Here, we review how clonal approaches have advanced our understanding of disease development, focusing on the acquisition of somatic mutations, clonal selection, driver mutation cooperation, and tumor evolution.

Single crystal to single crystal transformation of spin-crossover coordination polymers from 3D frameworks to 2D layers

2021 ◽  
Vol 9 (15) ◽  
pp. 5082-5087
Author(s):  
Yu Gong ◽  
Wang-Kang Han ◽  
Hui-Shu Lu ◽  
Qing-Tao Hu ◽  
Huan Tu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Single Crystal ◽  
Coordination Polymers ◽  
Ligand Exchange ◽  
Spin Crossover ◽  
Metal Organic Frameworks ◽  
Crystal Transformation ◽  
Metal Organic

New Hofmann-type metal–organic frameworks display rare and complete ligand exchange induced single crystal to single crystal transformations from 3D frameworks to 2D layers, accompanied by magnetic properties transition from two-step SCO behavior to hysteretic SCO behavior.

A p-Type PbS Quantum Dot Ink with Improved Stability for Solution Processable Optoelectronics

2021 ◽  
Author(s):  
Fiaz Ahmed ◽  
John Hardin Dunlap ◽  
Perry J. Pellechia ◽  
Andrew Greytak
Keyword(s):  
Quantum Dot ◽  
Ligand Exchange ◽  
Chemical Characterization ◽  
Single Step ◽  
Improved Stability ◽  
Solution Processable ◽  
P Type ◽  
Pbs Quantum Dot

A highly stable p-type PbS-QDs ink is prepared using a single-step biphasic ligand exchange route, overcoming instability encountered in previous reports. Chemical characterization of the ink reveals 3-mercaptopriopionic acid (MPA)...

scholarly journals Exploring the Characteristics and Influencing Factors of Leisure Walking Based on the Demand of Behavior

2021 ◽  
Vol 13 (8) ◽  
pp. 4105
Author(s):  
Yupei Jiang ◽  
Honghu Sun
Keyword(s):  
Health Benefits ◽  
Health Benefit ◽  
Public Health Research ◽  
Space Time ◽  
Time Behavior ◽  
Walking Behavior ◽  
Face To Face ◽  
Residential Neighborhood ◽  
The Impact

Leisure walking has been an important topic in space-time behavior and public health research. However, prior studies pay little attention to the integration and the characterization of diverse and multilevel demands of leisure walking. This study constructs a theoretical framework of leisure walking behavior demands from three different dimensions and levels of activity participation, space-time opportunity, and health benefit. On this basis, through a face-to-face survey in Nanjing, China (N = 1168, 2017–2018 data), this study quantitatively analyzes the characteristics of leisure walking demands, as well as the impact of the built environment and individual factors on it. The results show that residents have a high demand for participation and health benefits of leisure walking. The residential neighborhood provides more space opportunities for leisure walking, but there is a certain constraint on the choice of walking time. Residential neighborhood with medium or large parks is more likely to satisfy residents’ demands for engaging in leisure walking and obtaining high health benefits, while neighborhood with a high density of walking paths tends to limit the satisfaction of demands for space opportunity and health benefit. For residents aged 36 and above, married, or retired, their diverse demands for leisure walking are more likely to be fulfilled, while those with high education, medium-high individual income, general and above health status, or children (<18 years) are less likely to be fulfilled. These finding that can have important implications for the healthy neighborhood by fully considering diverse and multilevel demands of leisure walking behavior.

scholarly journals Size-resolved characterization of organic aerosol in the North China Plain: new insights from high resolution spectral analysis

2021 ◽  
Author(s):  
Weiqi Xu ◽  
Chun Chen ◽  
Yanmei Qiu ◽  
Conghui Xie ◽  
Yunle Chen ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
North China Plain ◽  
North China ◽  
Fine Particles ◽  
Large Fraction ◽  
Organic Aerosol ◽  
Size Distributions ◽  
The North ◽  
The Impact

Organic aerosol (OA), a large fraction of fine particles, has a large impact on climate radiative forcing and human health, and the impact depends strongly on size distributions. Here we...

scholarly journals Performance Analysis of Indentation Punch on High Energy Lithium Pouch Cells and Simulated Model Improvement

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1971
Author(s):  
Lihua Ye ◽  
Muhammad Muzamal Ashfaq ◽  
Aiping Shi ◽  
Syyed Adnan Raheel Shah ◽  
Yefan Shi
Keyword(s):  
Short Circuit ◽  
Lithium Ion ◽  
Mechanical Deformation ◽  
High Energy ◽  
State Of Charge ◽  
Punch Test ◽  
Short Course ◽  
Model Cell ◽  
The Impact

In this research, the aim relates to the material characterization of high-energy lithium-ion pouch cells. The development of appropriate model cell behavior is intended to simulate two scenarios: the first is mechanical deformation during a crash and the second is an internal short circuit in lithium-ion cells during the actual effect scenarios. The punch test has been used as a benchmark to analyze the effects of different state of charge conditions on high-energy lithium-ion battery cells. This article explores the impact of three separate factors on the outcomes of mechanical punch indentation experiments. The first parameter analyzed was the degree of prediction brought about by experiments on high-energy cells with two different states of charge (greater and lesser), with four different sizes of indentation punch, from the cell’s reaction during the indentation effects on electrolyte. Second, the results of the loading position, middle versus side, are measured at quasi-static speeds. The third parameter was the effect on an electrolyte with a different state of charge. The repeatability of the experiments on punch loading was the last test function analyzed. The test results of a greater than 10% state of charge and less than 10% state of charge were compared to further refine and validate this modeling method. The different loading scenarios analyzed in this study also showed great predictability in the load-displacement reaction and the onset short circuit. A theoretical model of the cell was modified for use in comprehensive mechanical deformation. The overall conclusion found that the loading initiating the cell’s electrical short circuit is not instantaneously instigated and it is subsequently used to process the development of a precise and practical computational model that will reduce the chances of the internal short course during the crash.

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