bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting Academic Performance in Mathematics through Online Learning Constructs and Content Proficiencies
Authors: Madrilejos Keith
Published: June 2024

This study explores the evaluation of online distance learning as a significant alternative to traditional education, specifically focusing on its application in Grade 11 mathematics education. The research, conducted in six public senior high schools in Quezon City District IV, employs a descriptive-correlational design and involves 873 Grade 11 students attending online classes. Constructs of online learning, including motivation, access and use of technology, perception, self-directed learning, and online teaching approaches, were examined to understand their impact on mathematics academic performance. The findings revealed that students strongly embraced self-directed learning in the online environment, demonstrating high motivation. Positive feedback was observed towards technology use, online teaching approaches, and the overall perception of online learning. Academic performance was generally satisfactory, with diverse achievements in content-based competencies like Functions and Their Graphs, Mathematics of Investment, and Math Logic. Significant low positive relationships were identified between mathematics academic performance and online learning constructs, as well as content-based competencies. Key predictors of mathematics academic performance included motivation, technology access and use, and online teaching approaches. However, the perception of online learning and self-directed learning did not significantly predict academic performance. These findings contribute to a multiple linear regression model explaining 24% of the variance, highlighting the need to optimize online learning for enhanced mathematics academic performance. Recommendations include students enhancing technology skills and self-directed learning, considering specialized mathematics classes, teachers intensifying instruction in crucial areas, and the Department of Education sustaining the Open High School program while simplifying essential learning competencies in General Mathematics. Future research should explore additional online learning factors for a comprehensive understanding of the subject.
Personality Profile, Self-Efficacy, and Teaching Performance of Junior High School Teachers
Authors: Gonzaga Ma. Corazon
Published: June 2024

Teachers’ performance is crucial for the achievement of educational success, and as a result, numerous empirical studies have been conducted to explore various factors influencing teachers' teaching performance. However, focusing on teachers' personality and self-efficacy could be a valuable effort in identifying factors that impact their performance in pursuing educational goals. This study aimed to determine the personality profile, level of self-efficacy, and teaching performance of junior high school teachers (JHS). A descriptive research design was employed with 111 respondents who answered the questionnaires. Results showed that, when grouped and compared according to age, sex, and length of service, there was no significant difference between the personality profile and the level of self-efficacy of JHS teachers except for the Agreeableness personality trait when grouped and compared according to sex. Similarly, there is no significant difference between the level of teaching performance when grouped and compared according to age and length of service, except for the variable of sex. Conversely, using the ChiSquare Test of Independence tool, the result depicted no significant correlation between the personality profile of JHS teachers and the level of teaching performance. Also, with the utilization of the Spearman Rank Coefficient Correlation, the level of self-efficacy and the level of teaching performance have not been found to be significantly correlated.
A Case Study on the Static Behavior of a Pedestrian Bridge Built with a Steel Pratt Truss Deck Bridge Supported by an Inclined Roller Support
Authors: Angeles Angelito , Almodovar Keith Zyren , Gopez Gericho , Lebre Kezia Irielle , Nucup Sharina Jolene , Samson Georvin
Published: June 2024

Construction of bridges commonly uses trusses due to their lightweight design, which can endure heavy loads and span large distances. However, there are instances when the supports of these trusses do not lie normally on a horizontal surface. For some, the supports lie on inclined foundations, which is the focus of this study. The main objective of this study is to present the basic theory of plane truss analysis with an inclined roller support using the Direct Stiffness Method (DSM) in comparison to the use of the Graphic Rapid Analysis Software Program (GRASP) to analyze the static behavior of the structure. Furthermore, a case study is conducted to check the effects of inclined supports on a plane truss structure. Based on the results, it was discovered that the introduction of inclined roller supports does have a negative effect on the stability of the structure.
Support Mechanism of School Administrators and Work Engagement of Teachers during the New Normal
Authors: Marcelino San Vielle
Published: June 2024

This study aims to determine the level of support mechanisms teachers received from their school supervisors during the New Normal and its impact on their work engagement. The respondents of this study are 90 teachers in Bacong District, Negros Oriental. The method used in the study is descriptive-correlational and employed a validated self-made questionnaire. Results revealed that the level of mental support teachers receive is high, while instructional and technological support levels are very high. The level of work engagement among the teachers is also high. The teaching position held by teachers is significantly and inversely related to their work engagement, indicating that the higher the teaching position held by the teacher, the lower their work engagement. Additionally, this study reveals that there is no significant relationship between the teachers' highest educational attainment, length of service, or number of training hours and their work engagement. These results underscore the importance of continued support for teachers, especially those in leadership roles, to enhance their engagement and effectiveness in the evolving educational landscape.
Issues, Challenges, and Coping Mechanisms of Out-of-Field Physical Education Teachers in Subject Delivery
Authors: Rivero Josua
Published: June 2024

This study explored the challenges and coping mechanisms of out-of-field Physical Education (PE) teachers. A descriptive-correlational design was employed with 30 out-of-field PE teachers as respondents. Data gathering tools included a survey questionnaire, while statistical treatments comprised Weighted Mean, Pearson Product-Moment Correlation Coefficient, and Determination of Coefficient. It was found that most respondents encountered issues, with the learning environment being less of a concern. Additionally, most respondents disagreed that supervisory assistance was evident in the curriculum, posing a challenge for out-of-field PE teachers. Seeking support from colleagues was identified as the most prominent coping mechanism, indicating a strong need for collaboration. However, other coping mechanisms were not strongly utilized by teachers. The influence of coping mechanisms varied across different issues and challenges. Finally, policy recommendations were developed based on the study's findings to support out-of-field PE teachers.
Unveiling Minds: Investigating Critical Thinking Traits of Students in Private Catholic Schools in Siquijor Province
Authors: Pagente Fritzie , Futalan Maria Chona
Published: June 2024

The study aimed to identify the critical thinking traits of students as possible determinants of their critical thinking skills and their relationship to selected variables. The researcher utilized a descriptive-correlational design and employed a systematic sampling technique to identify 130 randomly selected students from private Catholic institutions in the Province of Siquijor. Validated questionnaires were used, and multiple regression analysis, chi-square test, and weighted mean were employed for data analysis. The study found that senior high school students exhibit "high" levels of critical thinking traits in the following areas: truth-seeking, open-mindedness, analyticity, systematicity, critical thinking self-confidence, inquisitiveness, and cognitive maturity. Their critical thinking skills in interpretation, analysis, evaluation, inference, and self-regulation are also “high”. Furthermore, students who exhibit higher levels of truth-seeking, open-mindedness, and critical thinking self-confidence tend to have better critical thinking skills. Female students display more positive critical thinking traits compared to their male counterparts. Students in the Science, Technology, Engineering, and Mathematics (STEM) and Technical Vocational Livelihood (TVL) tracks exhibit the most desirable critical thinking traits and skills compared to other groups of students. These findings indicate the need for a concerted effort to maintain and improve critical thinking traits and skills across all student groups, with particular emphasis on gender disparities and stream-specific differences. Educators and policymakers can use these insights to better prepare students for academic success and future challenges.
Academic schools and social movements of Lviv University at the beginning of the XX century: The historical discoveries
Authors: Sukhyy Oleksiy
Published: June 2024

The relevance of the research topic lies in the importance of understanding the historical context in which scientific schools and social movements of the Lviv University were formed at the beginning of the 20th century, which will contribute to a better understanding of contemporary scientific and socio-cultural processes and will also facilitate the discovery of new perspectives in the study of the history of the university environment and its impact on society. The aim of the study is to systematize and analyze historical events and processes related to the development of education and science in Lviv at the beginning of the XX century in order to understand their impact on the modern socio-cultural environment. During the work, methods of archival research were used to analyze documents containing information about the university's activities, and historiographic analysis to review and study scientific works and sources related to its role in the socio-cultural context. As a result of the study, the role of the Lviv National University at the beginning of the XX century in the modernization of the educational and scientific sphere of Galicia was established through archival research of archival documents containing information about the university's activities, its founders, administration, educational process, student life, as well as through historiographic analysis of scientific works and sources related to its role in the socio-cultural context; the influence of the university environment on the socio-political life of the region and student initiatives was analyzed; the ideas of creating a separate Ukrainian university as an important step in national self-identification and the development of education in Galicia were generalized. The results of the study can be used to create historical narratives, document the development of education and science in the region, as well as to preserve and study cultural heritage
Libertad de empresa y su protección constitucional en Bolivia
Authors: Gamboa Alba Shirley
Published: June 2024

El presente artículo es parte de la revisión bibliográfica del avance de tesis de doctorado en Derecho Constitucional. Se presenta los resultados iniciales del análisis de la Constitución en relación a la protección que otorga a la libertad de empresa en el marco del nuevo modelo de Estado asumido por Bolivia. ¿Cuál es el alcance de la protección constitucional a la libertad de empresa?, es la interrogante que se responde en este trabajo, partiendo del hecho que la libertad de empresa es parte de los derechos económicos, por lo cual deben ser considerados en el marco de su contenido esencial para evitar su delimitación más allá de lo permitido. Entre las conclusiones relevantes, se advierte que la denominación de Estado social, plurinacional y comunitario confieren potestad de intervención en la actividad económica, limitando el ejercicio de la libertad de empresa. La investigación viene llevándose a cabo bajo el diseño cualitativo, tipo analítico-descriptivo.
Vairuotojų požiūris į nuobaudas : teisingumas, veiksmingumas, paskirtis ir jų psichologinės prielaidos
Authors: Markšaitytė Rasa , Šeibokaitė Laura , Endriulaitienė Auksė
Published: June 2024

Mokslo studijoje yra pristatomi atlikto tyrimo rezultatai, kuriame buvo siekiama atsakyti į klausimą, kokie psichologiniai veiksniai gali būti laikomi nuobaudų už KET pažeidimus (ne)veiksmingumo prielaidomis. Analizuojama, kokias nuostatas dėl nuobaudų išsako eismo dalyviai, kaip kelių eismo taisykles pažeidę ir nepažeidę vairuotojai vertina nuobaudų už skirtingo sunkumo KET pažeidimus paskirtį, teisingumą ir veiksmingumą. Taip pat pateikiamos tyrimo rezultatais pagrįstos rekomendacijos eismo saugumo didinimui bei vairuotojų mokymui.
Development of tax administration in the Russian Federation in the context of digital transformation
Authors: Mitin Dmitry Alekseevich
Published: June 2024

The digital transformation of business and the public sector has had a significant impact on business activities. New types of business have emerged, mainly carried out in the digital space. In addition, new means of payment have emerged: cryptocurrencies and digital financial assets. These facts are shocks to tax administration models created to interact with taxpayers engaged in traditional activities. In this regard, in 2020, the Organization for Economic Co-operation and Development (OECD) at the XIII plenary meeting of the Forum on Tax Administration proposed the concept of digital transformation of tax administration “Tax Administration 3.0: Digital transformation of tax administration.” Taking into account the noted factors, the article provides a theoretical analysis of the risks caused by digital transformation for the purposes of tax administration, and also considers the best practices for leveling risks, including through the digitalization of tax administration. The subject of the study is the digital transformation of tax administration in the Russian Federation. The purpose of the study is to develop proposals for the development of tax administration in the Russian Federation, taking into account the best global practices, as well as using advanced technologies of the digital economy. As part of the study, the following research methods were used: retrospective analysis, synthesis, comparison and forecasting. The article provides a general analysis of the phenomenon of digital transformation and the associated risks for the purposes of tax administration; OECD proposals for the digital transformation of tax administration were reviewed, including their advantages and disadvantages; actual approaches to the transformation of the tax administration model used in the Russian Federation are noted. The scientific novelty of the work is expressed in the proposed further directions for the development of tax administration in the Russian Federation, including: the development of electronic document management; expanding the use of Blockchain technology; using the capabilities of smart contracts to automate the process of calculating and paying taxes. The solutions proposed in the study can be used in the practical implementation of measures to develop tax administration in the Russian Federation.
Phytochemical Assay and in – Vitro Cytotoxicity Assessment of Cassava Peel (Manihot esculenta) from Ethanol and Ethyl Acetate Extract Against Cervical Cancer Cells (HeLa)
Authors:   Faculty of Medicine, Universitas Indonesia, Jl. Salemba Raya No.6, Kenari, Kec. Senen, Kota Jakarta Pusat, Daerah Khusus Ibukota Jakarta, 10430, Indonesia, Hari Soejono Alice , Dwira Surya ,   Department of Medical Chemistry, Faculty of Medicine, Universitas Indonesia, Jl. Salemba Raya No.6, Kenari, Kec. Senen, Kota Jakarta Pusat, Daerah Khusus Ibukota Jakarta, 10430, Indonesia, Sari Puji ,   Department of Biology, Faculty of Medicine, University of Indonesia, Jl. Salemba Raya 6, 10430, Jakarta, Indonesia
Published: June 2024

Introduction: Cervical cancer is a type of cancer that develops in a woman’s cervix. It is a result of HPV (Human Papilloma Virus) and is one of the deadliest types of cancer. Some cervical cancer management including chemotherapy, which until recently continues to develop to cure the condition, is relatively expensive and comes with multiple different side effects. Method: Manihot esculenta undergoes multilevel maceration with the solvent of ethanol and ethyl acetate. This leads to the formation of ethanol extract and ethyl acetate extract of Manihot esculenta that is analyzed through phytochemical assay and thin layer chromatography (TLC) to determine the phytochemical components present. This is then followed by cytotoxicity assessment against Hela cervical cancer cells using MTT test. Result: Manihot esculenta peel contains secondary metabolites including tannin, flavonoid, alkaloid, and triterpenoid. Cytotoxicity activity evaluation for ethanol shows moderate cytotoxicity with IC50 value of 228.26 μg/mL. While ethyl acetate shows active cytotoxicity activity with IC50 value of 56.47 μg/mL. The data distribution of IC50 value of all extracts is normal (p>0.05). There was a statistically insignificant difference in IC50 value between extracts based on one-way ANOVA. Conclusion: Manihot esculenta peel contains phytochemical components that are cytotoxic towards HeLa cervical cancer cells.
Fitness landscape of substrate-adaptive mutations in evolved APC transporters
Authors: Karapanagioti Foteini , Atlason Úlfur Á. , Slotboom Dirk J. , Poolman Bert , Obermaier Sebastian
Published: June 2024

The emergence of new protein functions is crucial for the evolution of organisms. This process has been extensively researched for soluble enzymes, but it is largely unexplored for membrane transporters, even though the ability to acquire new nutrients from a changing environment requires evolvability of transport functions. Here, we demonstrate the importance of environmental pressure in obtaining a new activity or altering a promiscuous activity in members of the Amino acid-Polyamine-organoCation (APC)-type yeast amino acid transporters family. We identify APC members that have broader substrate spectra than previously described. Using
in vivo
experimental evolution, we evolve two of these transporter genes,
AGP1
and
PUT4
, towards new substrate specificities. Single mutations on these transporters are found to be sufficient for expanding the substrate range of the proteins, while retaining the capacity to transport all original substrates. Nonetheless, each adaptive mutation comes with a distinct effect on the fitness for each of the original substrates, illustrating a trade-off between the ancestral and evolved functions. Collectively, our findings reveal how substrate-adaptive mutations in membrane transporters contribute to fitness and provide insights into how organisms can use transporter evolution to explore new ecological niches.
Obox4 promotes zygotic genome activation upon loss of Dux
Authors: Guo Youjia , Kitano Tomohiro , Inoue Kimiko , Murano Kensaku , Hirose Michiko , Li Ten D , Sakashita Akihiko , Ishizu Hirotsugu , Ogonuki Narumi , Matoba Shogo , Sato Masayuki , Ogura Atsuo , Siomi Haruhiko
Published: June 2024

Once fertilized, mouse zygotes rapidly proceed to zygotic genome activation (ZGA), during which long terminal repeats (LTRs) of murine endogenous retroviruses with leucine tRNA primer (MERVL) are activated by a conserved homeodomain-containing transcription factor, DUX. However, Dux-knockout embryos produce fertile mice, suggesting that ZGA is redundantly driven by an unknown factor(s). Here, we present multiple lines of evidence that the multicopy homeobox gene, Obox4, encodes a transcription factor that is highly expressed in mouse two-cell embryos and redundantly drives ZGA. Genome-wide profiling revealed that OBOX4 specifically binds and activates MERVL LTRs as well as a subset of murine endogenous retroviruses with lysine tRNA primer (MERVK) LTRs. Depletion of Obox4 is tolerated by embryogenesis, whereas concomitant Obox4/Dux depletion markedly compromises embryonic development. Our study identified OBOX4 as a transcription factor that provides genetic redundancy to preimplantation development.
Dynamic Tracking of Native Polyclonal Hematopoiesis in Adult Mice
Authors: Liu Suying , Adams Sarah E. , Zheng Haotian , Ehnot Juliana , Jung Seul K. , Jeffrey Greer , Menna Theresa , Purton Louise E. , Lee Hongzhe , Kurre Peter
Published: June 2024

Hematopoietic dysfunction has been associated with a reduction in the number of active precursors. However, precursor quantification at homeostasis and under diseased conditions is constrained by the scarcity of available methods. To address this issue, we optimized a method for quantifying a wide range of hematopoietic precursors. Assuming the random induction of a stable label in precursors following a binomial distribution, the estimation depends on the inverse correlation between precursor numbers and the variance of precursor labeling among independent samples. Experimentally validated to cover the full dynamic range of hematopoietic precursors in mice (1 to 10
5
), we utilized this approach to demonstrate that thousands of precursors, which emerge after modest expansion during fetal-to-adult transition, contribute to native and perturbed hematopoiesis. We further estimated the number of precursors in a mouse model of Fanconi Anemia, showcasing how repopulation deficits can be segregated into autologous (cell proliferation) and non-autologous causes (lack of precursor). Our results support an accessible and reliable approach for precursor quantification, emphasizing the contemporary perspective that native hematopoiesis is highly polyclonal.
Nitric oxide modulates contrast suppression in a subset of mouse retinal ganglion cells
Authors: Gonschorek Dominic , Goldin Matías A. , Oesterle Jonathan , Schwerd-Kleine Tom , Arlinghaus Ryan , Zhao Zhijian , Schubert Timm , Marre Olivier , Euler Thomas
Published: June 2024

Neuromodulators have major influences on the regulation of neural circuit activity across the nervous system. Nitric oxide (NO) has been shown to be a prominent neuromodulator in many circuits and has been extensively studied in the retina. Here, it has been associated with the regulation of light adaptation, gain control, and gap junctional coupling, but its effect on the retinal output, specifically on the different types of retinal ganglion cells (RGCs), is still poorly understood. In this study, we used two-photon Ca
2+
imaging and multi-electrode array (MEA) recordings to measure light-evoked activity of RGCs in the ganglion cell layer in the
ex vivo
mouse retina. This approach allowed us to investigate the neuromodulatory effects of NO on a cell type-level. Our findings reveal that NO selectively modulates the suppression of temporal responses in a distinct subset of contrast-suppressed RGC types, increasing their activity without altering the spatial properties of their receptive fields. Given that NO release is triggered by quick changes in light levels under photopic conditions, we propose that these RGC types signal fast contrast changes to higher visual regions. Remarkably, we found that about one-third of the RGC types, recorded using two-photon Ca
2+
imaging, exhibited consistent, cell type-specific adaptational response changes throughout an experiment, independent of NO. By employing a paired-recording paradigm, we could disentangle those additional adaptational response changes from drug-induced modulations. Taken together, our research highlights the selective neuromodulatory effects of NO on RGCs and emphasizes the need of considering non-pharmacological activity changes, like adaptation, in such study designs.
A Rare Case of Signet Ring Cell Carcinoma Arising on Duodenal Brunner’s Gland Hyperplasia Successfully Treated Via Endoscopic Resection
Authors: Lee Hae Rin , Lee Bong Eun , Kim Kyung Bin , Kim Gwang Ha , Lee Moon Won , Joo Dong Chan
Published: June 2024

Signet-ring cell carcinoma (SRCC) is a rare tumor that most commonly occurs in the stomach. Duodenal SRCCs are extremely uncommon and account for approximately 1% of duodenal adenocarcinomas. Although Brunner’s gland hyperplasia (BGH) is a benign duodenal condition, studies have reported several cases of adenocarcinoma originating in an area of BGH. We report a rare case of early-stage SRCC originating in an area of BGH that was successfully treated using endoscopic mucosal resection. Based on the mucin phenotype observed in this case, it is reasonable to conclude that SRCC originated from gastric metaplasia in the area of BGH. Although BGH is a benign condition, careful evaluation is warranted for early detection of combined neoplasms.
Air, 2. Effects of Air Pollutants
Authors: Eikmann Thomas , Scholl Gerhard
Published: November 2011

The article contains sections titled:1.Effects on Humans2.General Effects2.1.Specific Pollutants2.2.Persons Needing Special Protection2.3.Carcinogenicity, Mutagenicity, and Teratogenicity3.Environmentally Relevant Air Pollutants3.1.Sulfur Dioxide3.2.Nitrogen Oxides3.3.Ozone3.4.Carbon Monoxide3.5.Dusts3.6.Lead3.7.Cadmium3.8.Arsenic3.9.Benzene3.10.Polycyclic Aromatic Hydrocarbons3.11.Diesel Motor Emissions3.12.Dioxins and Furans4.Effects on Plants4.1.Relationship between Immission and Effect4.2.Effect of Individual Pollutants4.2.1.Sulfur Dioxide4.2.2.Hydrogen Fluoride4.2.3.Hydrogen Chloride and Chlorine4.2.4.Nitrogen Dioxide and Ammonia4.2.5.Hydrogen Sulfide4.2.6.Ethylene4.2.7.Ozone and Other Photooxidants4.2.8.Dust4.2.9.Acid Rain
Air, 6. Photochemical Degradation
Authors: Simmler Walter
Published: November 2011

The article contains sections titled:

1.

Introduction

2.

Natural and Anthropogenic Emissions

3.

Reaction Cycles in the Atmosphere

3.1.

The Troposphere

3.2.

The Stratosphere

4.

Interaction with Surface Layers of Aquatic and Terrestrial Environments

5.

Measurement and Computation of Degradability

5.1.

Lifetime in the Homogeneous Gas Phase

5.2.

Lifetimes of Adsorbates Aerosols

5.3.

Assessment and Evaluation
Ammonia, 3. Production Plants
Authors: Appl Max
Published: November 2011

The article contains sections titled:1.Complete Ammonia Production Plants1.1.Steam Reforming Ammonia Plants1.1.1.The Basic Concept of Single‐Train Plants1.1.2.Further Developments1.1.3.Minimum Energy Requirement for Steam Reforming Processes1.1.4.Commercial Steam Reforming Ammonia Processes1.1.4.1.Advanced Conventional Processes1.1.4.2.Processes with Reduced Primary Reformer Firing1.1.4.3.Processes Without a Fired Primary Reformer (Exchanger Reformer)1.1.4.4.Processes Without a Secondary Reformer (Nitrogen from Air Separation)1.2.Ammonia Plants based on Partial Oxidation1.2.1.Ammonia Plants Based on Heavy Hydrocarbons1.2.2.Ammonia Plants Using Coal as Feedstock1.3.Waste‐Heat Boilers1.4.Single‐Train Capacity – Mega Ammonia Plants2.Modernization of Older Plants (Revamping)3.Material Considerations for Equipment Fabrication
Atomic Spectroscopy, 2. Absorption Spectrometry
Authors: Broekaert José A. C. , Hywel Evans E.
Published: November 2011

The article contains sections titled:1.Principles2.Spectrometers2.1.Spectrometer Details2.2.Primary Sources3.Flame Atomic Absorption3.1.Flames and Burners3.2.Nebulizers3.3.Figures of Merit4.Electrothermal Atomic Absorption4.1.Atomizers4.2.Thermochemistry4.3.Figures of Merit5.Special Techniques5.1.Hydride and Cold Vapor Techniques5.2.Direct Solid Sampling5.3.Indirect Determinations6.Background Correction6.1.Deuterium Lamp Technique6.2.Zeeman Effect Technique6.3.Smith ‐ Hieftje Technique6.4.Coherent Forward Scattering7.Fields of Application
Atomic Spectroscopy, 3. Emission Spectrometry
Authors: Broekaert José A. C. , Hywel Evans E.
Published: November 2011

The article contains sections titled:1.Principles2.Spectrometers3.Flame Emission4.Arcs and Sparks5.Plasma Sources5.1.Direct Current Plasmas5.2.Inductively Coupled Plasmas5.3.Microwave Plasmas6.Glow Discharges6.1.Hollow Cathodes6.2.Furnace Emission Spectrometry6.3.Glow Discharges with Flat Cathodes6.4.New Developments7.Laser Sources
Chlorinated Benzenes and Other Nucleus‐Chlorinated Aromatic Hydrocarbons
Authors: Beck Uwe , Löser Eckhard
Published: November 2011

The article contains sections titled:1.Introduction2.Chlorinated Benzenes2.1.Physical Properties2.2.Chemical Properties2.3.Production2.3.1.Monochlorobenzene2.3.2.Dichlorobenzenes2.3.3.Trichlorobenzenes2.3.4.Tetrachlorobenzenes2.3.5.Pentachlorobenzene2.3.6.Hexachlorobenzene2.4.Quality and Analysis2.5.Storage and Transportation2.6.Uses2.7.Toxicology3.Chlorinated Toluenes3.1.Physical Properties3.2.Chemical Properties3.3.Production3.3.1.Monochlorotoluenes3.3.2.Dichlorotoluenes3.3.3.Trichlorotoluenes3.3.4.Tetrachlorotoluenes3.3.5.Pentachlorotoluene3.4.Quality and Analysis3.5.Storage and Transportation3.6.Uses3.7.Toxicology4.Chlorinated Biphenyls4.1.Physical and Chemical Properties4.2.Disposal4.3.Analysis4.4.Storage and Transportation4.5.Uses4.6.Toxicology5.Chlorinated Naphthalenes5.1.Physical Properties5.2.Chemical Properties5.3.Production5.4.Quality and Analysis5.5.Storage and Transportation5.6.Uses5.7.Toxicology6.Environmental Protection7.Economic Aspects
Fungicides, Agricultural, 2. Individual Fungicides
Authors: Müller Franz , Ackermann Peter , Margot Paul
Published: November 2011

The article contains sections titled:1.Introduction2.Fungicidal Antibiotics3.Inorganic Compounds4.Organometallic and Metal–Organic Compounds5.Dithiocarbamates5.1.Metal‐Free Dithiocarbamates5.2.Metal‐Containing Dithiocarbamates6.Imides7.Amides8.Dicarboximides9.Aliphatic Compounds10.Phenyl‐Substituted Compounds11.Organophosphates12.Phosphites13.Benzimidazoles14.Anilides15.Acylamino Acids16.Amides17.Inhibitors of Sterol Biosynthesis17.1.Triazoles17.2.Imidazoles18.Pyridines19.Pyrimidines20.Pyrroles21.Morpholines22.Strobulins23.Carbamates24.Dinitrophenols25.Oxazoles26.Quinolines27.Quinones28.Quinoxalines29.Thiazoles and Thiazolidines30.Thiocarbamates31.Triazines32.Unclassified Fungicides
Iron, 3. Direct Reduction Processes
Authors: Formanek Lothar , Rose Fritz
Published: November 2011

The article contains sections titled:

1.

Introduction

2.

Shaft Furnace Processes for Direct Reduction

3.

Retort Processes

4.

Fluidized‐Bed Processes

5.

Rotary Kiln Processes
Paper and Board, 1. General
Authors: Holik Herbert , Tschudin Peter F.
Published: November 2011

The article contains sections titled:

1.

Paper and Board Today

2.

Overview of the Manufacturing Process for Paper and Board

3.

Historical Background and General Aspects

3.1.

Invention of Paper

3.2.

Chinese Paper

3.3.

Arab Paper

3.4.

Medieval European Paper

3.5.

Mechanization and Industrialization

3.6.

Paper Machines

3.7.

Pulping and Sizing

3.8.

From Industrialization to Automation and Globalization: Technical and Economic Trends of the 19th and 20th Centuries

4.

Economic Aspects
Poly(4‐Methyl‐1‐Pentene)
Authors: Heggs T. Geoffrey
Published: November 2011

The article contains sections titled:

1.

Introduction

2.

Raw Materials

2.1.

Monomers

2.2.

High‐Melting Nucleating Polymers

2.3.

Catalysts

3.

Industrial Manufacture

4.

Polymer Structure

4.1.

Homopolymer

4.2.

Copolymers

5.

Properties of PMP Products

5.1.

Optical Properties

5.2.

Stability and Chemical Resistance

5.3.

Mechanical Properties

5.4.

Electrical Properties

5.5.

Surface Properties and Permeability

5.6.

Rheology

6.

Economic Aspects

7.

Fabrication and Applications

7.1.

Fabrication

7.2.

Applications

8.

Health and Environmental Aspects
Surface and Thin‐Film Analysis, 4 Photon Detection
Authors: Raue Roderich , Kunde Klaus , Engel Aloys
Published: November 2011

The article contains sections titled:1.Total‐Reflection X‐ray Fluorescence Analysis (TXRF)1.1.Principles1.2.Instrumentation1.3.Spectral Information1.4.Quantification1.5.Applications1.5.1.Particulate and Film‐Type Surface Contamination1.5.2.Semiconductors1.5.2.1.Depth Profiling by TXRF and Multilayer Structures1.5.2.2.Vapor Phase Decomposition (VPD) and Droplet Collection2.Glow Discharge Optical Emission Spectroscopy (GD‐OES)2.1.Principles2.2.Instrumentation2.3.Spectral Information2.4.Quantification2.5.Depth Profiling2.6.Applications3.Surface‐Sensitive IR and Raman Spectroscopy; Ellipsometry3.1.Reflection ‐ Absorption IR Spectroscopy (RAIRS)3.1.1.Principles3.1.2.Instrumentation and Applications3.2.Surface Raman Spectroscopy3.2.1.Principles3.2.2.Surface‐Enhanced Raman Scattering (SERS)3.2.2.1.Instrumentation3.2.2.2.Spectral Information3.2.2.3.Applications3.2.3.Nonlinear Optical Spectroscopy3.3.UV ‐ VIS ‐ IR Ellipsometry (ELL)3.3.1.Principles3.3.2.Instrumentation3.3.3.Applications4.Other Photon‐Detecting Techniques4.1.Appearance‐Potential Methods4.1.1.Soft X‐Ray Appearance‐Potential Spectroscopy (SXAPS)4.1.2.Disappearance‐Potential Spectroscopy (DAPS)4.2.Inverse Photoemission Spectroscopy (IPES) and Bremsstrahlung Isochromat Spectroscopy (BIS)4.3.Ion‐Beam Spectrochemical Analysis (IBSCA)
Textile Auxiliaries, 3. Sizing Agents
Authors: Schlüter Kaspar
Published: November 2011

The article contains sections titled:

1.

Introduction

2.

Sizing Methods

3.

Sizing Agents Based on Natural Raw Materials

3.1.

Starch and Starch Derivatives

3.2.

Sodium Carboxymethyl Cellulose

3.3.

Sizing Agents Based on Other Natural Raw Materials

4.

Synthetic Sizing Agents

4.1.

Poly(Vinyl Alcohols)

4.2.

Poly(meth)acrylates

4.3.

Polyester Condensates

4.4.

Other Synthetic Sizing Agents

5.

Sizing Additives

6.

Commercial Products
Wastewater, 5. Physical Treatment
Authors: Mann Theo , Koglin Bernd , von Kienle Hartmut , Wegmann Uwe , Weisbrodt Walter
Published: November 2011

The article contains sections titled:1.Adsorptive Purification1.1.Adsorption1.2.Adsorption Isotherms1.3.Adsorption Kinetics1.4.Adsorbents1.5.Adsorption Processes1.6.Adsorbent Recovery and Regeneration1.6.1.Regeneration of Carbon Adsorbents1.6.2.Regeneration of Aluminum Oxide1.6.3.Regeneration of Adsorber Resins1.7.Applications of the Adsorptive Purification of Wastewater1.7.1.Purification with Activated Carbon1.7.2.Purification with Lignite Coke1.7.3.Purification with Aluminum Oxide1.7.4.Treatment with Adsorber Resins1.7.5.Purification with Isopolyacids2.Mechanical Treatment2.1.Screening Processes2.2.Gravity Processes2.2.1.Sedimentation2.2.2.Floatation2.2.3.Flotation2.2.3.1.Basic Principle2.2.3.2.Contact and Adhesion of Particles to Gas Bubbles; Flotation Kinetics2.2.3.3.Implementation, Fields of Application, and Operational Experience2.2.3.4.Costs and Benefits2.2.4.Foaming‐Out Process2.2.5.Centrifugal Processes
Wastewater, 6. Incineration
Authors: Moldenhauer Wolfgang , Mischer Günter
Published: November 2011

The article contains sections titled:1.Introduction2.Legal Aspects3.Distinctions with Respect to Other Processes, and Evaluation Criteria3.1.Calorific Value3.2.Wastewater Constituents4.Incineration Plants4.1.Combustion Chambers4.2.Immersion Heating Chambers4.3.Fluidized‐Bed Furnaces4.4.Rotary Kilns5.Emissions: Off‐Gases, Water, and Solid Waste
Anxiolytics
Authors: Dubroeucq Marie‐Christine , Stutzmann Jean‐Marie , Manfré Franco , Capet Marc , Böhme Georg Andrees
Published: November 2011

The article contains sections titled:1.Introduction2.Benzodiazepines2.1.1,4‐Benzodiazepines2.2.Other Benzodiazepines3.Carbamates4.Other Anxiolytics5.Anxiolytics Under Development
Efficiency Enhanced Hybrid Solar Cells Using a Blend of Quantum Dots and Nanorods
Authors: Jeltsch Krischan F. , Schädel Martin , Bonekamp Jörg‐Bernd , Niyamakom Phenwisa , Rauscher Frank , Lademann Hans W. A. , Dumsch Ines , Allard Sybille , Scherf Ullrich , Meerholz Klaus
Published: November 2011

The cell performance of organic‐inorganic hybrid photovoltaic devices based on CdSe nanocrystals and the semiconducting polymer poly[2,6‐(4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]‐dithiophene)‐alt‐4,7‐(2,1,3‐benzothiadiazole)] (PCPDTBT) is strongly dependent on the applied polymer‐to‐nanocrystal loading ratio and the annealing temperature. It is shown here that higher temperatures for the thermal annealing step have a beneficial impact on the nanocrystal phase by forming extended agglomerates necessary for electron percolation to enhance the short‐circuit current. However, there is a concomitant reduction of the open‐circuit voltage, which arises from energy‐level alterations of the organic and the inorganic component. Based on quantum dots and PCPDTBT, we present an optimized organic–inorganic hybrid system utilizing an annealing temperature of 210 °C, which provides a maximum power conversion efficiency of 2.8%. Further improvement is obtained by blending nanocrystals of two different shapes to compose a favorable n‐type network. The blend of spherical quantum dots and elongated nanorods results in a well‐interconnected pathway for electrons within the p‐type polmer matrix, yielding maximum efficiencies of 3.6% under simulated AM 1.5 illumination.
sp3‐sp2 C‐C Bond Formation via Brønsted Acid Trifluoromethanesulfonic Acid‐Catalyzed Direct Coupling Reaction of Alcohols and Alkenes
Authors: Yue Hui‐Lan , Wei Wei , Li Ming‐Ming , Yang Yong‐Rong , Ji Jian‐Xin
Published: November 2011

A novel and efficient trifluoromethanesulfonic acid‐catalyzed sp3‐sp2 CC bond formation reaction through the direct coupling of alcohols with alkenes has been realized under mild conditions. The present protocol provides an attractive approach to a diverse range of polysubstituted olefins in good to excellent yields with high stereo‐ and regioselectivities.
Dehydration of Benzyl Alcohols in Phosphonium Ionic Liquids: Synthesis of Ethers and Alkenes
Authors: Kalviri Hassan A. , Kerton Francesca M.
Published: November 2011

The dehydration of benzylic alcohols has been studied in several phosphonium ionic liquids in the absence of any metal catalysts. Benzyl ethers and alkenes were obtained from primary and secondary benzylic alcohols in good to excellent yields for these reactions. Commercially available hydrophobic phosphonium ionic liquids containing the trihexyl(tetradecyl)phosphonium cation paired with six different anions were used for the reactions under microwave irradiation. The interaction of the substrate with the ionic liquid was investigated using different NMR techniques, such as NOESY NMR. The effects of cation and anions on the behaviour of these ionic liquids in the reactions were studied in order to understand the mechanism. A catalytic cycle is proposed involving activation of the benzyl alcohol by the phosphonium cation.
Total Synthesis of Symbioramide: a Flexible Approach for the Efficient Preparation of Structural Isomers
Authors: Prévost Sébastien , Ayad Tahar , Phansavath Phannarath , Ratovelomanana‐Vidal Virginie
Published: November 2011

A concise, enantioselective total synthesis of symbioramide, starting from simple achiral compounds and racemic α‐amino‐β‐keto ester derivatives is reported. This highly flexible strategy allowed the efficient preparation of seven structural isomers of the natural product as well. The synthesis relies on a convergent route that involves the efficient stereoselective reduction of a α‐keto‐β‐yne ester, and the dynamic kinetic resolution of an α‐amino‐β‐keto ester through ruthenium‐mediated asymmetric hydrogenation.
Modeling the thermochemical degradation of biomass inside a fast pyrolysis fluidized bed reactor
Authors: Bruchmüller J. , van Wachem B. G. M. , Gu S. , Luo K. H. , Brown R. C.
Published: November 2011

A fast pyrolysis process in a bubbling fluidized bed has been modeled, thoroughly reproduced and scrutinized with the help of a combined Eulerian/Lagrangian simulation method. The 3‐D model is compared to experimental results from a 100 g/h bubbling fluidized bed pyrolyzer including such variables as particle composition at the outlet and gas/vapor/water yields as a function of fluidization conditions, biomass moisture concentrations, and bed temperatures. Multiprocessor simulations on a high‐end computer have been carried out to enable the tracking of each of the 0.8 million individual discrete sand and biomass particles, making it possible to look at accurate and detailed multiscale information (i.e., any desired particle property, trajectory, particle interaction) over the entire particle life time. The overall thermochemical degradation process of biomass is influenced by local flow and particle properties and, therefore, accurate and detailed modeling reveals unprecedented insight into such complex processes. It has been found, that the superficial fluidization velocity is important while the particle moisture content is less significant for the final bio‐oil yield. © 2011 American Institute of Chemical Engineers AIChE J, 58: 3030–3042, 2012
Thermal, morphological, and X‐ray study of polymer‐clay nanocomposites
Authors: Nigam Vineeta , Soni Hitesh , Saroop Madhumita , Verma G.L. , Bhattacharya A.S. , Setua D.K.
Published: November 2011

Synthesis and characterization of polymer nanocomposites consisting of diglycidyl ether of bisphenol‐A with inorganic as well as organically modified nanosized clay fillers, for example, vermiculites and montmorillonite, obtained from trade, are studied. Confirmations of intercalation and exfoliation characteristics of these fillers into the cured epoxy resin matrix have been investigated by wide angle X‐ray diffraction studies. Scanning electron microscopy and atomic force microscopy techniques have been adopted to assess the nature of filler dispersion, size of the agglomerates, and the polymer‐filler adhesion. While significant improvement in the mechanical properties (i.e., tensile, flexural strength, and modulus) has been observed, the thermo‐oxidative stability of the composites measured by thermogravimetric analysis showed only marginal improvement. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Commenting on YouTube videos: From guatemalan rock to El Big Bang
Authors: Thelwall Mike , Sud Pardeep , Vis Farida
Published: November 2011

YouTube is one of the world's most popular websites and hosts numerous amateur and professional videos. Comments on these videos might be researched to give insights into audience reactions to important issues or particular videos. Yet, little is known about YouTube discussions in general: how frequent they are, who typically participates, and the role of sentiment. This article fills this gap through an analysis of large samples of text comments on YouTube videos. The results identify patterns and give some benchmarks against which future YouTube research into individual videos can be compared. For instance, the typical YouTube comment was mildly positive, was posted by a 29‐year‐old male, and contained 58 characters. About 23% of comments in the complete comment sets were replies to previous comments. There was no typical density of discussion on YouTube videos in the sense of the proportion of replies to other comments: videos with both few and many replies were common. The YouTube audience engaged with each other disproportionately when making negative comments, however; positive comments elicited few replies. The biggest trigger of discussion seemed to be religion, whereas the videos attracting the least discussion were predominantly from the Music, Comedy, and How to & Style categories. This suggests different audience uses for YouTube, from passive entertainment to active debating.
Predictive effects of structural variation on citation counts
Authors: Chen Chaomei
Published: November 2011

A critical part of a scientific activity is to discern how a new idea is related to what we know and what may become possible. As the number of new scientific publications arrives at a rate that rapidly outpaces our capacity of reading, analyzing, and synthesizing scientific knowledge, we need to augment ourselves with information that can effectively guide us through the rapidly growing intellectual space. In this article, we address a fundamental issue concerning what kinds of information may serve as early signs of potentially valuable ideas. In particular, we are interested in information that is routinely available and derivable upon the publication of a scientific paper without assuming the availability of additional information such as its usage and citations. We propose a theoretical and computational model that predicts the potential of a scientific publication in terms of the degree to which it alters the intellectual structure of the state of the art. The structural variation approach focuses on the novel boundary‐spanning connections introduced by a new article to the intellectual space. We validate the role of boundary‐spanning in predicting future citations using three metrics of structural variation—namely, modularity change rate, cluster linkage, and Centrality Divergence—along with more commonly studied predictors of citations such as the number of coauthors, the number of cited references, and the number of pages. Main effects of these factors are estimated for five cases using zero‐inflated negative binomial regression models of citation counts. Key findings indicate that (a) structural variations measured by cluster linkage are a better predictor of citation counts than are the more commonly studied variables such as the number of references cited, (b) the number of coauthors and the number of references are both good predictors of global citation counts to a lesser extent, and (c) the Centrality Divergence metric is potentially valuable for detecting boundary‐spanning activities at interdisciplinary levels. The structural variation approach offers a new way to monitor and discern the potential of newly published papers in context. The boundary‐spanning mechanism offers a conceptually simplified and unifying explanation of the roles played by commonly studied extrinsic properties of a publication in the study of citation behavior.
Interaction of hesperetin glucuronide conjugates with human BCRP, MRP2 and MRP3 as detected in membrane vesicles of overexpressing baculovirus‐infected Sf9 cells
Authors: Brand Walter , Oosterhuis Berend , Krajcsi Peter , Barron Denis , Dionisi Fabiola , van Bladeren Peter J. , Rietjens Ivonne M. C. M. , Williamson Gary
Published: November 2011

The citrus flavonoid hesperetin (4′‐methoxy‐3′,5,7‐trihydroxyflavanone) is the aglycone of hesperidin, the major flavonoid present in sweet oranges. Hesperetin 7‐O‐glucuronide (H7G) and hesperetin 3′‐O‐glucuronide (H3′G) are the two most abundant metabolites of hesperetin in vivo. In this study, their interaction with specific ABC transporters, believed to play a role in the disposition and bioavailability of hesperetin, was studied using Sf9 membranes from cells overexpressing human BCRP (ABCG2), MRP2 (ABCC2) and MRP3 (ABCC3). Both H7G and H3′G were tested for their potential to activate and inhibit ATPase activity, and to inhibit vesicular transport by these transporters. Both H7G and H3′G demonstrated interaction with all tested ABC transporters, especially with BCRP and MRP3. An interesting difference between H7G and H3′G was seen with respect to the interaction with BCRP: H7G stimulated the ATPase activity of BCRP up to 76% of the maximal effect generated by the reference activator sulfasalazine, with an EC50 of 0.45 µ m, suggesting that H7G is a high affinity substrate of BCRP, whereas H3′G did not stimulate BCRP ATPase activity. Only moderate inhibition of BCRP ATPase activity at high H3′G concentrations was observed. This study provides information on the potential of hesperetin glucuronide conjugates to act as specific ABC transporter substrates or inhibitors and indicates that regio‐specific glucuronidation could affect the disposition of hesperetin. Copyright © 2011 John Wiley & Sons, Ltd.