scholarly journals Chemical transformations at carbothermal reduction of barium and boron from oxides

2019 ◽  
Vol 62 (11) ◽  
pp. 846-851
Author(s):  
A. A. Akberdin ◽  
M. M. Karbaev
Keyword(s):  
Cast Iron ◽  
Chemical Transformations ◽  
Technological Properties ◽  
New Methods ◽  
First Case ◽  
Recent Developments ◽  
Steel Grades ◽  
Inclusions In Steel ◽  
Low Solubility

Alloys of boron and barium are applied to improve the quality of cast iron, steel, aluminum and other metals. The first industry produces mainly in the form of ferroboron, containing 6 – 17 % of boron depending on the brand. It is produced by an expensive aluminothermic method due to the use of boric anhydride and aluminum powder. At the same time, presence of aluminum in the metal is inevitable, it degrades the technological properties of cast iron and forms line alumina inclusions in steel. Extra-furnace removal of Al leads to oxidation of boron and its loss with slags. Therefore, the authors have proposed new methods for smelting boron-containing ferroalloys. Recent developments include the production technology of boron-containing ferrosilicon, which has been tested in industrial conditions. But its use may be limited in smelting of low-silicon steel grades. Barium is an effective modifier. Due to its low solubility in iron, it is produced in the form of alloys with silicon or aluminum. In the first case, silicides (BaSi, BaSi2 ) are formed and therefore such alloys are called silicon barium or ferrosilicon with barium. In present work, there has been studied the possibility of producing modifier with boron and barium ferroalloy. It was believed that the simultaneous presence of barium and boron in it can be demand for industry. At the first stage, chemistry of transformations in BaO– B2O3 – C ironless system was considered using the carbothermic method. A complete thermodynamic analysis of chemical interactions in this system was performed in the temperature range of 1400 – 3000 K. Possibility of the formation of a condensed metal phase due to boron carbides (B4C) and barium (BaC2 ), as well as barium hexaboride (BaB6 ) is shown. The obtained data can serve as the basis for creation of a new ferroalloy simultaneously containing boron and barium.

Boilerplate

2012 ◽  
Author(s):  
Margaret Jane Radin
Keyword(s):  
Economic Efficiency ◽  
Analytical Framework ◽  
Daily Basis ◽  
Regulatory Agencies ◽  
Jury Trial ◽  
Comprehensive Treatment ◽  
New Methods ◽  
And Control ◽  
Fine Print

Boilerplate—the fine-print terms and conditions that we become subject to when we click “I agree” online, rent an apartment, or enter an employment contract, for example—pervades all aspects of our modern lives. On a daily basis, most of us accept boilerplate provisions without realizing that should a dispute arise about a purchased good or service, the nonnegotiable boilerplate terms can deprive us of our right to jury trial and relieve providers of responsibility for harm. Boilerplate is the first comprehensive treatment of the problems posed by the increasing use of these terms, demonstrating how their use has degraded traditional notions of consent, agreement, and contract, and sacrificed core rights whose loss threatens the democratic order. This book examines attempts to justify the use of boilerplate provisions by claiming either that recipients freely consent to them or that economic efficiency demands them, and it finds these justifications wanting. It argues that our courts, legislatures, and regulatory agencies have fallen short in their evaluation and oversight of the use of boilerplate clauses. To improve legal evaluation of boilerplate, the book offers a new analytical framework, one that takes into account the nature of the rights affected, the quality of the recipient's consent, and the extent of the use of these terms. It goes on to offer possibilities for new methods of boilerplate evaluation and control, and concludes by discussing positive steps that NGOs, legislators, regulators, courts, and scholars could take to bring about better practices.

ВЛИЯНИЕ БИОКОНСЕРВАНТА «СИЛОСТАН» НА КАЧЕСТВО СЕНАЖА ИЗ КОЗЛЯТНИКА ВОСТОЧНОГО И СЫРОПРИГОДНОСТЬ МОЛОКА КОРОВ

2019 ◽  
pp. 51-56
Author(s):  
A.S. KARAMAEVA ◽  
N.V. SOBOLEVA ◽  
S.V. KARAMAEV
Keyword(s):  
Serum Proteins ◽  
Metabolizable Energy ◽  
Holstein Cows ◽  
Technological Properties ◽  
Holstein Breed ◽  
Feed Digestibility ◽  
Ayrshire Breed ◽  
Milk Coagulation ◽  
Dry Substance

От породы коров и ее особенностей зависят эффективность использования кормов, качество и технологические свойства молока. Материалом исследований служили коровы чернопестрой голштинской и айрширской пород. Для повышения качества сенажа из козлятника восточного использовали микробиологический препарат. В готовом корме с биоконсервантом содержание сухого вещества было выше на 3,66, обменной энергии на 8,04, сырого протеина на 10,86, переваримого протеина на 13,59. Улучшение качества корма оказало положительное влияние на метаболические процессы в рубце подопытных коров. Независимо от технологии приготовления сенажа коровы айрширской породы лучше переваривали, по сравнению с голштинами, сухое вещество на 2,062,91 (Р0,05), органическое на 1,212,04 (Р0,05), сырой протеин на 2,222,49 (Р0,05), БЭВ на 0,921,36, но при этом голштины лучше переваривали сырой жир на 2,732,78 (Р0,05) и сырую клетчатку на 1,551,86. В результате внесения в сенаж биоконсерванта Силостан и улучшения переваримости корма у коров опытных групп значительно улучшился химический состав и технологические свойства молока. Очень важно для сыроделия, что в молоке коров, получавших в рационе сенаж с биоконсервантом, повышается массовая доля казеина на 2,42,7, а доля сывороточных белков и фракции казеина, которые не свертываются под действием сычужного фермента, наоборот, снижается на 1,41,5 и на 0,30,9, соответственно. Уменьшается продолжительность свертывания молока сычужным ферментом, снижаются потери сухого вещества с сывороткой, и увеличивается выход казеинового сгустка. Плотность казеинового сгустка повышается в молоке голштинских коров на 14,3, айрширских на 5,7 и составляет, соответственно, 1,92 и 2,96 г/см2.The efficiency of feed use, the quality, as well as technological properties of milk depend on cow breed and its characteristics. Blackandwhite Holstein and Ayrshire breeds were used as the material for research. Microbiological preparation was used to increase the quality of halyage made of Eastern galega. The content of dry substance in the readymade feed was 3.66 higher, the metabolizable energy 8.04 higher, raw protein 10.86 higher, and digestible protein 13.59. Improvement of feed quality positively influenced the metabolic processes in the rumen of experimental cows. Without regard to the technology of halyage preparation, cows of Ayrshire breed showed betterdigestion of dry substance by 2.06 2.91 (P0.05) than Holstein cows, organic substance by 1.21 2.04 (P0.05), raw protein by 2.22 2.49 (P0.05), nitrogenfree extractive fraction by 0.92 1.36, but Holstein breed showed better digestion of raw fat by 2.73 2.78 (P0.05) and raw fiber by 1.55 1.86. Chemical composition and technological properties of milk improved significantly as a result of addition of Silostan biopreservative to the halyage and improvement of feed digestibility in cows from test groups. The fact that the mass percentage of casein is increased by 2.4 2.7, and the share of serum proteins and ycasein fractions which do not coagulate under the influence of enzyme rennet is inversely decreased by 1.4 1.5 and 0.3 0.9, accordingly, is very important for cheese making. The duration of milk coagulation with rennet is decreased, the loss of dry substance with serum is decreased, and the yield of casein coagulate is increased. Density of casein coagulate is increased in the milk of Holstein cows by 14.3, Ayrshire cows by 5.7, and equals to 1.92 and 2.96 g/cm2, accordingly.

Green Synthesized Nanomaterials as Theranostic Platforms for Cancer Treatment: Principles, Challenges and the Road Ahead

2019 ◽  
Vol 26 (8) ◽  
pp. 1311-1327 ◽  
Author(s):  
Pala Rajasekharreddy ◽  
Chao Huang ◽  
Siddhardha Busi ◽  
Jobina Rajkumari ◽  
Ming-Hong Tai ◽  
...  
Keyword(s):  
Nanoparticle Synthesis ◽  
Research Field ◽  
Synthesis Methods ◽  
Synthetic Approach ◽  
Future Directions ◽  
The Road ◽  
New Methods ◽  
Recent Developments ◽  
Theranostic Applications ◽  
Insight Into

With the emergence of nanotechnology, new methods have been developed for engineering various nanoparticles for biomedical applications. Nanotheranostics is a burgeoning research field with tremendous prospects for the improvement of diagnosis and treatment of various cancers. However, the development of biocompatible and efficient drug/gene delivery theranostic systems still remains a challenge. Green synthetic approach of nanoparticles with low capital and operating expenses, reduced environmental pollution and better biocompatibility and stability is a latest and novel field, which is advantageous over chemical or physical nanoparticle synthesis methods. In this article, we summarize the recent research progresses related to green synthesized nanoparticles for cancer theranostic applications, and we also conclude with a look at the current challenges and insight into the future directions based on recent developments in these areas.

scholarly journals Dental Education Challenges during the COVID-19 Pandemic Period in Italy: Undergraduate Student Feedback, Future Perspectives, and the Needs of Teaching Strategies for Professional Development

Healthcare ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 454
Author(s):  
Giuseppe Varvara ◽  
Sara Bernardi ◽  
Serena Bianchi ◽  
Bruna Sinjari ◽  
Maurizio Piattelli
Keyword(s):  
Undergraduate Student ◽  
Teaching And Learning ◽  
Dental Education ◽  
Student Feedback ◽  
Categorical Variables ◽  
Practical Training ◽  
Learning Approaches ◽  
New Methods ◽  
E Learning

The COVID-19 pandemic literally stopped most human movement and activities as it initially spread, which included dental practices and dental education. This defined the need for significative changes in teaching and learning with the use of “e-learning” methods, also for traineeships. This study was designed to determine the undergraduate student perception of these new methods as part of their education. This involved 353 students attending the Dental School of the G. D’Annunzio University of Chieti–Pescara, from the first to the sixth years. A questionnaire in Italian and was set-up using “Google Forms” and sent by email to the students. The questionnaire was divided into three parts: the first part included questions for general information, including age, sex and year of course; the second part had multiple choice questions related to their evaluation of the e-learning teaching, using a scale of opinion in the replies to each question (e.g., “scarce”, “fair”, “satisfying”, “very good” and “excellent”); and the third part included two open questions to indicate the strengths and limitations of these new teaching and learning approaches. The categorical variables in the first and second parts of the questionnaire were evaluated using Chi squared tests, setting significance at p < 0.05, while the comments were evaluated qualitatively. The student feedback showed significant appreciation (p < 0.05) of the new methods and the efforts that the lecturers put in to provide lectures of as high a quality as possible. However, a lack of practical training was significantly perceived as an important problem in the structure of their new curriculum (p < 0.05). COVID-19 has been an epic tragedy that has hit the human population not only in terms of health and healthcare, but also quality of life. This includes the quality of dental education within universities. However, the pandemic can be seen to also represent motivation to invest in the necessary technological innovation to deliver the best possible education to our future dentists.

Study on the Behavior of the Cast-Iron Bonded Grinding Wheel to Machining Properties of Hard and Brittle Materials

2007 ◽  
Vol 24-25 ◽  
pp. 229-232
Author(s):  
S.L. Ma ◽  
Wei Li ◽  
Cong Rong Zhu ◽  
J. Zhang ◽  
H.C. Ye
Keyword(s):  
Grain Size ◽  
Cast Iron ◽  
Tungsten Carbide ◽  
Surface Quality ◽  
Ground Surface ◽  
Grinding Wheel ◽  
Different Grain Size ◽  
Grinding Efficiency ◽  
Machining Properties

Tungsten carbide which is a hard and brittle material was ground by cast-iron bonded diamond wheel with ELID (Electrolytic In-Process Dressing) technique, for the purpose of getting high efficiency, super-precision machining. Three kinds of cast-iron bonded diamond wheels with different grain size were adopted to get different grinding efficiency and surface quality of workpieces. The grinding properties of cast-iron bonded grinding wheels with different grain size and the ground surface quality of tungsten carbide are discussed in this paper. The experiment results indicate that, under the same feeding amount, the grinding efficiency of the wheel with bigger grain size is higher, and it could make the dimension accuracy of the workpiece controllable, but the wheel with smaller grain size could get better ground surface quality. The two grinding phases are decided by the ratio between the size of abrasive grain and the thickness of the oxide layer on the grinding wheel.

scholarly journals The Benefits of Smart Nanoparticles in Dental Applications

2021 ◽  
Vol 22 (5) ◽  
pp. 2585
Author(s):  
Silvia Vasiliu ◽  
Stefania Racovita ◽  
Ionela Aurica Gugoasa ◽  
Maria-Andreea Lungan ◽  
Marcel Popa ◽  
...  
Keyword(s):  
Metallic Nanoparticles ◽  
Periodontal Diseases ◽  
Dental Materials ◽  
Moisture Stress ◽  
New Methods ◽  
Strong Trend ◽  
Scientific World ◽  
Oral Environment ◽  
Recent Developments ◽  
Dental Applications

Dentistry, as a branch of medicine, has undergone continuous evolution over time. The scientific world has focused its attention on the development of new methods and materials with improved properties that meet the needs of patients. For this purpose, the replacement of so-called “passive” dental materials that do not interact with the oral environment with “smart/intelligent” materials that have the capability to change their shape, color, or size in response to an externally stimulus, such as the temperature, pH, light, moisture, stress, electric or magnetic fields, and chemical compounds, has received much attention in recent years. A strong trend in dental applications is to apply nanotechnology and smart nanomaterials such as nanoclays, nanofibers, nanocomposites, nanobubbles, nanocapsules, solid-lipid nanoparticles, nanospheres, metallic nanoparticles, nanotubes, and nanocrystals. Among the nanomaterials, the smart nanoparticles present several advantages compared to other materials, creating the possibility to use them in various dental applications, including preventive dentistry, endodontics, restoration, and periodontal diseases. This review is focused on the recent developments and dental applications (drug delivery systems and restoration materials) of smart nanoparticles.

Dysphagia: implications for older people

2013 ◽  
Vol 24 (1) ◽  
pp. 41-57 ◽  
Author(s):  
N Miller ◽  
J Patterson
Keyword(s):  
Quality Of Life ◽  
Health Economic ◽  
Older People ◽  
Legal Issues ◽  
Validity And Reliability ◽  
Future Developments ◽  
Ongoing Work ◽  
Recent Developments ◽  
Management Of Dysphagia

SummaryDysphagia represents a salient concern in many conditions prevalent in older people. There are direct implications for morbidity and mortality. The importance of recognizing and managing dysphagia in hospital and the community also extends to psychosocial impact and quality of life, as well as health, economic and ethical-legal issues. This review outlines reasons for the importance of recognizing and treating dysphagia. It then proceeds to look at recent developments in our understanding of the nature, assessment and management of dysphagia in older people. Whilst there are well-established practices in assessment and management, ongoing work continues to challenge the validity and reliability of many methods. These concerns are covered and directions for future developments highlighted.

scholarly journals Great differences in performance and outcome of high-throughput sequencing data analysis platforms for fungal metabarcoding

MycoKeys ◽  
2018 ◽  
Vol 39 ◽  
pp. 29-40 ◽  
Author(s):  
Sten Anslan ◽  
R. Henrik Nilsson ◽  
Christian Wurzbacher ◽  
Petr Baldrian ◽  
Leho Tedersoo ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Sequencing ◽  
Computation Time ◽  
Potential Effect ◽  
Data Sets ◽  
Sequencing Data ◽  
Operational Taxonomic Units ◽  
High Throughput Sequencing Data ◽  
Recent Developments

Along with recent developments in high-throughput sequencing (HTS) technologies and thus fast accumulation of HTS data, there has been a growing need and interest for developing tools for HTS data processing and communication. In particular, a number of bioinformatics tools have been designed for analysing metabarcoding data, each with specific features, assumptions and outputs. To evaluate the potential effect of the application of different bioinformatics workflow on the results, we compared the performance of different analysis platforms on two contrasting high-throughput sequencing data sets. Our analysis revealed that the computation time, quality of error filtering and hence output of specific bioinformatics process largely depends on the platform used. Our results show that none of the bioinformatics workflows appears to perfectly filter out the accumulated errors and generate Operational Taxonomic Units, although PipeCraft, LotuS and PIPITS perform better than QIIME2 and Galaxy for the tested fungal amplicon dataset. We conclude that the output of each platform requires manual validation of the OTUs by examining the taxonomy assignment values.

A Semantic Differential for Evaluating the Sound Quality of Fan Systems

2017 ◽  
Author(s):  
Carolin Feldmann ◽  
Thomas Carolus ◽  
Marc Schneider
Keyword(s):  
Principal Component ◽  
Semantic Differential ◽  
Sound Quality ◽  
Heat Pumps ◽  
First Case ◽  
Objective Metrics ◽  
Main Components ◽  
Air Conditioning Systems ◽  
The University

Fans are main components e.g. in heating, ventilating and air conditioning systems for vehicles or buildings, cooling units of engines and electronic circuits, and household appliances such as kitchen exhaust hoods or vacuum cleaners. End-users increasingly demand a high sound quality of their system or device. The overall objective of a recent research project at the University of Siegen is a multidimensional assessment of fan sound quality. In a first step an advanced novel semantic differential for the assessment of fan-related sounds is established with the aid of carefully designed jury tests. Eventually, this semantic differential is employed for sound quality jury tests of fans in kitchen exhaust hoods, heat pumps and air purifiers as a first case. Finally, a prediction model is suggested, which relates the outcome from the jury tests to objective metrics. A principal component analysis is carried out and yields five main assessment criteria with 23 relevant adjective scales. The results show that the perceived sound quality of fan systems is mainly determined by the loudness and tonality of the sound. The spectral content (represented by the sharpness) as well as the time structure (represented by the roughness) have no significant impact on perceived sound quality of the fan systems investigated.

Reaction Kinetics for the Hydrolysis of Titanium Isopropoxide Carboxylate Complexes

1992 ◽  
Vol 271 ◽  
Author(s):  
Charles D. Gagliardi ◽  
Dilum Dunuwila ◽  
Beatrice A. Van Vlierberge-Torgerson ◽  
Kris A. Berglund
Keyword(s):  
Carboxylic Acids ◽  
Ceramic Materials ◽  
Titanium Isopropoxide ◽  
General Interest ◽  
Chemical Transformations ◽  
Molecular Precursors ◽  
Novel Applications ◽  
Kinetics Of ◽  
Hydrolysis Of

ABSTRACTTitanium alkoxides modified by carboxylic acids have been widely studied as the molecular precursors to ceramic materials. These alkoxide complexes have also been very useful in the formation of stable, porous, optically clear films having many novel applications such as chemical sensors, catalytic supports, and ion-exchange media. To improve the processing of these materials, it is essential to better understand the kinetics of the chemical transformations which occur.The kinetics of the hydrolysis reaction are studied for selected carboxylic acids using Raman spectroscopy to probe the chemistry of the process. The study has a special emphasis on the titanium isopropoxide-valeric acid system due to the superior quality of these films over other carboxylates. Greater knowledge of the hydrolysis kinetics allows increased control over the quality of the film materials and should be of general interest to those working with modified metal alkoxides.

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