bluuebunny/crossref_metadata_2025 huggingface dataset:
Net irrigation requirement under different climate scenarios using AquaCrop over Europe
Authors: Busschaert Louise , de Roos Shannon , Thiery Wim , Raes Dirk , De Lannoy Gabriëlle J. M.
Published: January 2022

Abstract. Global soil water availability is challenged by the effects of climate change and a growing population. On average 70 % of freshwater extraction is attributed to agriculture, and the demand is increasing. In this study, the effects of climate change on the evolution of the irrigation water requirement to sustain current crop productivity are assessed by using the FAO crop growth model AquaCrop version 6.1. The model is run at 0.5° lat × 0.5° lon resolution over the European mainland, assuming a general C3-type of crop, and forced by climate input data from the Inter-Sectoral Impact Model Intercomparison Project phase three (ISIMIP3). First, the performance of AquaCrop surface soil moisture (SSM) simulations using historical meteorological input from two ISIMIP3 forcing datasets is evaluated with satellite-based SSM estimates. When driven by ISIMIP3a reanalysis meteorology for the years 2011–2016, daily simulated SSM values have an unbiased root-mean-square difference of 0.08 and 0.06 m3m−3 with SSM retrievals from the Soil Moisture Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP) missions, respectively. When forced with ISIMIP3b meteorology from five Global Climate Models (GCM) for the years 2011–2020, the historical simulated SSM climatology closely agrees with the climatology of the reanalysis-driven AquaCrop SSM climatology as well as the satellite-based SSM climatologies. Second, the evaluated AquaCrop model is run to quantify the future irrigation requirement, for an ensemble of five GCMs and three different emission scenarios. The simulated net irrigation requirement (Inet) of the three summer months for a near and far future climate period (2031–2060 and 2071–2100) is compared to the baseline period of 1985–2014, to assess changes in the mean and interannual variability of the irrigation demand. Averaged over the continent and the model ensemble, the far future Inet is expected to increase by 67 mm year–1 (+30 %) under a high emission scenario Shared Socioeconomic Pathway (SSP) 3-7.0. Central and southern Europe are the most impacted with larger Inet increases. The interannual variability of Inet is likely to increase in northern and central Europe, whereas the variability is expected to decrease in southern regions. Under a high mitigation scenario (SSP1-2.6), the increase in Inet will stabilize around 40 mm year–1 towards the end of the century and interannual variability will still increase but to a smaller extent. The results emphasize a large uncertainty in the Inet projected by various GCMs.
Rigid Sets and Coherent Sets in Realistic Ocean Flows
Authors: Feppon Florian , Lermusiaux Pierre
Published: January 2022

Abstract. This paper focuses on the extractions of Lagrangian Coherent Sets from realistic velocity fields obtained from ocean data and simulations, each of which can be highly resolved and non volume-preserving. We introduce two novel methods for computing two formulations of such sets. First, we propose a new “diffeomorphism-based” criterion to extract “rigid sets”, defined as sets over which the flow map acts approximately as a rigid transformation. Second, we develop a matrix-free methodology that provides a simple and efficient framework to compute “coherent sets” with operator methods. Both new methods and their resulting rigid sets and coherent sets are illustrated and compared using three numerically simulated flow examples, including a high-resolution realistic, submesoscale to large-scale dynamic ocean current field in the Palau Island region of the western Pacific Ocean.
Forearc density structure of the overriding plate in the northern area of the giant 1960 Valdivia earthquake
Authors: Maksymowicz Andrei , Montecinos-Cuadros Daniela , Díaz Daniel , Segovia María José , Reyes Tomás
Published: January 2022

Abstract. The objective of this work is to analyse the density
structure of the continental forearc in the northern segment of the 1960 Mw 9.6 Valdivia earthquake. Regional 2D and local 3D density models have been
obtained from available gravity data in the area, complemented by new
gravimetric stations. Models are constrained by independent
geophysical and geological information and new TEM and MT soundings. The results
show a segmentation of the continental wedge along and perpendicular to the
margin, highlighting a high-density anomaly, below the onshore forearc
basin, that limits the late Paleozoic–early Mesozoic metamorphic basement in
the region where Chaitenia terrane has been proposed. A progressive landward
shift of this anomaly correlates with the high slip patch of the giant 1960
Mw 9.6 Valdivia earthquake. Based on these results, we propose that the
horizontal extension of the less rigid basement units conforming the marine
wedge and Coastal Cordillera domain could modify the process of stress
loading during the interseismic periods, and also that changes in position
and extension of the late Paleozoic–early Mesozoic accretionary complex
could be linked with the frictional properties of the interplate boundary.
This analysis provides new evidence of the role of the overriding plate
structure in the seismotectonic process in subduction zones.
Impact of Timanian thrust systems on the late Neoproterozoic–Phanerozoic tectonic evolution of the Barents Sea and Svalbard
Authors: Koehl Jean-Baptiste P. , Magee Craig , Anell Ingrid M.
Published: January 2022

Abstract. The Svalbard Archipelago consists of three basement terranes that record a
complex Neoproterozoic–Phanerozoic tectonic history, including four
contractional events (Grenvillian, Caledonian, Ellesmerian, and Eurekan) and
two episodes of collapse- to rift-related extension (Devonian–Carboniferous
and late Cenozoic). Previous studies suggest that these three terranes likely
accreted during the early to mid-Paleozoic Caledonian and Ellesmerian
orogenies. Yet recent geochronological analyses show that the northwestern
and southwestern terranes of Svalbard both record an episode of amphibolite
(–eclogite) facies metamorphism in the latest Neoproterozoic, which may
relate to the 650–550 Ma Timanian Orogeny identified in northwestern
Russia, northern Norway, and the Russian Barents Sea. However, discrete
Timanian structures have yet to be identified in Svalbard and the Norwegian
Barents Sea. Through analysis of seismic reflection, as well as regional
gravimetric and magnetic data, this study demonstrates the presence of
continuous thrust
systems that are several kilometers thick, NNE-dipping, deeply buried, and extend thousands of kilometers from northwestern Russia to
northeastern Norway, the northern Norwegian Barents Sea, and the Svalbard
Archipelago. The consistency in orientation and geometry, as well as apparent
linkage between these thrust systems and those recognized as part of the
Timanian Orogeny in northwestern Russia and Novaya Zemlya, suggests that the
mapped structures are likely Timanian. If correct, these findings would
imply that Svalbard's three basement terranes and the Barents Sea were
accreted onto northern Norway during the Timanian Orogeny and should hence
be attached to Baltica and northwestern Russia in future
Neoproterozoic–early Paleozoic plate tectonics reconstructions. In the
Phanerozoic, the study suggests that the interpreted Timanian thrust systems
represent major preexisting zones of weakness that were reactivated,
folded, and overprinted by (i.e., controlled the formation of new) brittle
faults during later tectonic events. These faults are still active at
present and can be linked to folding and offset of the seafloor.
Phosphorus dynamics during early soil development in a cold desert: insights from oxygen isotopes in phosphate
Authors: Frkova Zuzana , Pistocchi Chiara , Vystavna Yuliya , Capkova Katerina , Dolezal Jiri , Tamburini Federica
Published: January 2022

Abstract. At the early stages of pedogenesis, the dynamics of phosphorus (P)
in soils are controlled by microbial communities, the physicochemical
properties of the soil and the environmental conditions. While various
microorganisms involved in carrying out biogeochemical processes have been
identified, little is known about the actual contribution of microbial
processes, such as organic P hydrolysis and microbial P turnover, to P
cycling. We thus focused on processes driven by microbes and how they affect
the size and cycling of organic and inorganic soil P pools along a soil
chronosequence in the Chamser Kangri glacier forefield (Western Himalayas).
The rapid retreat of the glacier allowed us to study the early stages of
soil formation under a cold arid climate. Biological P transformations were
studied with the help of the isotopic composition of oxygen (O) in phosphate
(δ18OP) coupled to sequential P fractionation performed on
soil samples (0–5 cm depth) from four sites of different age spanning 0 to
100–150 years. The P bound to Ca, i.e., 1 M HCl-extractable P,
still represented 95 % of the total P stock after approximately 100 years of soil
development. Its isotopic composition was similar to the parent material at
the most developed site. Primary phosphate minerals, possibly apatite,
mostly comprised this pool. The δ18OP of the available P
and the NaOH-extractable inorganic P instead differed from that of the
parent material, suggesting that these pools underwent biological turnover.
The δ18OP of the available P was mostly controlled by the
microbial P, suggesting fast exchanges occurred between these two pools
possibly fostered by repeated freezing–thawing and drying–rewetting cycles.
The release of P from organic P becomes increasingly important with soil
age, constituting one-third of the P flux to available P at the oldest site.
Accordingly, the lighter isotopic composition of the P bound to Fe and Al
oxides at the oldest site indicated that this pool contained phosphate
released by organic P mineralization. Compared to previous studies on early
pedogenesis under alpine or cold climate, our findings suggest a much slower
decrease of the P-bearing primary minerals during the first 100 years of
soil development under extreme conditions. However, they provide evidence
that, by driving short-term P dynamics, microbes play an important role in
controlling the redistribution of primary P into inorganic and organic soil
P pools.
LEO TOLSTOY AND ENGLISH FAMILY NOVEL: CONTINUITY AND CONTROVERSY. LEO TOLSTOY AND ENGLISH FAMILY NOVEL
Authors: Astvatsaturova Vera
Published: January 2022

In this article the family theme of Tolstoy’s novels is compared with the one of novels of his English contemporary authors. The problems of the novel “Anna Karenina” looks like the problems of the English novels, but is solved quite different. If the heroes of English novels drive from the foreign terrible world to the comfortable home world, then the heroes of Tolstoy novels are attacked by an alien force, destroying their happiness.
УПРАВЛІННЯ ІННОВАЦІЙНОЮ СКЛАДОВОЮ ОБОРОННО-ПРОМИСЛОВОГО КОМПЛЕКСУ
Authors: О.О. Усаченко , Л.М. Родченко , І.Ю. Родченко
Published: January 2022

При аналізі функціонування існуючих підприємств оборонно-промислового комплексу визначено чинники, що негативно впливають на управління інноваційною діяльністю. Переважна частина наукових досліджень і розробок все ще здійснюється тими організаціями науково-дослідних і дослідно-конструкторських робіт, які найбільш віддалені від потреб підприємств і попиту на продукцію з боку промислового сектора, в тому числі і оборонно-промислового комплексу. Два фактори - низькі інноваційні можливості оборонно-промислових підприємств і відносна ізольованість галузевих дослідних інститутів від промислових підприємств - чинять негативний вплив на рівень конкурентоспроможності, а також на конструювання, виробництво і реалізацію продукції в Україні. На ділі можна сказати, що ці два фактори є найсуттєвішими перешкодами на шляху перетворення української системи наукових досліджень і розробок в українську інноваційну систему.
СТУДЕНТИ-ІНОЗЕМЦІ В УКРАЇНІ ЯК ОБ’ЄКТ ДЕРЖАВНОЇ ЕТНОНАЦІОНАЛЬНОЇ ПОЛІТИКИ
Authors: А.В. Меляков , А.В. Черноіваненко
Published: January 2022

В статті проаналізовано становище студентів-іноземців, які навчаються в українських університетах як окремого об’єкту етнонаціональної політики. Показано, що культурні та соціальні проблеми цієї категорії студентів вивчені недостатньо. Доведено, що творчий та інтелектуальний потенціал іноземних студентів може бути корисним при проведенні навчальних та просвітницьких заходів не лише у вищих, але й у середніх навчальних закладах. Показано, що роль органів публічної влади полягає у запобіганні та профілактиці міжетнічних конфліктів в студентському середовищі. Зроблено висновок про необхідність врахування національного чинника під час створення інклюзивного освітнього простору у вищих навчальних закладах.
The Bureaucratic Perils of Presidentialism: Political Impediments to Good Governance in Latin America
Authors: Polga-Hecimovich John
Published: January 2022

In the face of poorly performing bureaucracies, public management specialists and policy experts have been quick to suggest administrative reforms. Yet, since governance lies at the nexus of politics and administration, reforms limited to the administrative dimension are likely to fall short without concomitant political change. This essay argues that in contemporary Latin America, certain political-institutional arrangements or institutional traits are more likely to produce (in)effective governance than others. Specifically, Latin American presidentialism creates several “perils” for governance, including: the rigidity and short time horizons of presidentialism; multipartyism under presidentialism; weakly institutionalized party systems and non-programmatic parties; an imbalance of power between strong presidents and weak legislatures; the plebiscitarian nature of presidentialism; and democratic backsliding and the centralization of power in the presidency. These institutional traits incentivize patronage, promote myopic policymaking, and weaken bureaucratic autonomy. To illustrate how they manifest themselves in public policy, the paper uses evidence from the region’s responses to the Covid-19 pandemic, then concludes by suggesting political reforms that may help to improve governance in the region.
Political Failure and Bureaucratic Potential in Africa
Authors: Wimpy Cameron
Published: January 2022

Recent scholarship theorizes that shortcomings in good governance are a result of political, not bureaucratic, failures. These challenges are no less important in the developing world, and they are particularly acute in many African countries where resources are scarce and political development is relatively limited. Although the impacts of public administration quality on governance outcomes in Africa are well established, the empirical relationship between political failures and bureaucratic capacity remains underexplored. In addition, political issues in developing countries often cause bureaucratic pathologies to vary across the additional dimensions of corruption, judicial independence, and political pluralism. Using a combination of unique datasets, I turn the recent theories on political failure into testable propositions for how these processes unfold in the African context. The findings are of interest both for improving governance in developing countries and adding to the growing body of literature examining the severity of the challenges posed by political failure in various contexts.
Electronic Development of Student Worksheets Based on Science, Technology, Engineering, Art, and Mathematics to Improve Creative Thinking Ability of Class V Elementary School Students in Science Learning
Authors: Andartiani Kinanti , Sulistyorini Sri , S Pranoto Yuli Kurniawati
Published: January 2022

This study aimed to analyze the validity, effectiveness, and practicality of the E-LKPD (Electronic Student Worksheet) to improve the creative thinking skills of fifth grade students at SDN 1 Kutoharjo and SDN 2 Kutoharjo after participating in STEAM-based learning (Science, Technology, Engineering, Art, and Mathematics). This study used research and development procedures with reference to the 4D model (Define, Design, Develop, and Disseminate) but this research was only up to the develop stage. The research design used was "One Groups Pretest-Posttest Design" with 72 students as research subjects. The research instrument used was observation sheet, interview sheet, expert validation test sheet, written test (pretest and posttest), and questionnaire sheet (questionnaire). The results of the research, it can be analyzed that the validity of the E-LKPD according to the material expert validator is 91.6 in the very valid category, the media expert validator was 75 in the valid category, and the language expert validator was 85 in the very valid category. The effectiveness of E-LKPD according to the results of the N-Gain test calculation of 0.61 was included in the category of quite effective and showed that there was a significant increase in creative thinking skills before and after using STEAM-based E-LKPD with 91% classical completeness results with complete criteria. STEAM-based E-LKPD was declared practical according to the results of teacher and student respondents which showed that teacher respondents scored 83 and 80 in the very attractive category and student respondents produced an average score of 81 in the very attractive category. The conclusion of the research was the development of STEAM-based E-LKPD was suitable for distance learning activities and can improve students' creative thinking skills.

Keywords: E-LKPD IPA, STEAM, Creative Thinking.
Analisis kemampuan pedagogical content knowledge (PCK) calon guru MI pada konsep IPA dalam menghadapi pendidikan abad 21
Authors: Abdurrahman Dudung , Nurmatin Suci
Published: January 2022

Penelitian ini bertujuan untuk menganalisis kemampuan Pedagogical Content Knowledge (PCK) guru MI pada konsep IPA dalam rangka menghadapi pendidikan abad 21. Enam orang orang mahasiswa yang mengikuti mata kuliah Pendidikan IPA dijadikan sebagai partisipan. Data kemampuan PCK subjek diperoleh berdasarkan hasil observasi saat partisipan melaksanakan simulasi pembelajaran. Hasil analisis kemampuan PCK partisipan saat simulasi pembelajaran menunjukkan bahwa kemampuan pedagogi dan konten secara terpisah sudah cukup baik, namun integrasi antara kemampuan pedagogi dengan kemampuan kontent belum terlihat baik. Dengan demikian kemampuan PCK partisipan dalam menghadapi pendidikan abad 21 belum maksimal.
Pemanfaatan aplikasi CBT sebagai alat evaluasi pada mata kuliah dasar-dasar pendidikan MIPA dan morfologi tumbuhan
Authors: Septiana Nurul
Published: January 2022

Penelitian ini dilakukan untuk mendeskripsikan pemanfaatan aplikasi CBT (Computer Based Test) pada ujian tengah semester dan ujian akhir semester pada Mata Kuliah Dasar-dasar Pendidikan MIPA dan Morfologi Tumbuhan. Dalam penelitian ini metode yang digunakan yaitu deskriptif kualitatif dengan jumlah sampel 29 mahasiswa. Teknik pengambilan data yang digunakan adalah dengan menyebarkan angket menggunakan Google Form, dilanjutkan dengan melakukan kajian dan analisis data. Simpulan dari penelitian ini adalah bahwa lebih dari 50% mahasiswa memberikan respon yang positif dalam pelaksanaan ujian menggunakan CBT pada aspek perasaan senang, ketertarikan, motivasi, keinginan, dan keterampilan dalam penggunaan aplikasi. Aplikasi CBT memiliki banyak kelebihan dibandingkan evaluasi berbasis PBT, tetapi juga masih terdapat kelemahan terutama terkait koneksi jaringan dan sulitnya memantau kejujuran mahasiswa selama pelaksanaan tes.
Discovery and studies of stellar associations. The Key to Understanding Star Evolution
Authors:   Byurakan Astrophysical Observatory, Armenia, Akopian A. A.
Published: January 2022

The review presents works carried out in BAO in the period 1947-70. It tells about the history and significance of one of the greatest discoveries of the twentieth century - stellar associations. Among the fundamental works of Ambartsumian and BAO studies of stellar associations occupy a special place. Their discovery radically changed the existing theories of star formation and evolution and "revived" the slowly dying (as previously assumed) Universe. The discovery of stellar associations proved that star formation occurs in our era. Ambartsumian's ideas clarified the existing and somewhat confusing theory of stellar evolution and gradually became one of the generally accepted directions of the theory of stellar evolution. For more than 75 years, scientists from the BAO and many observatories around the world have been studying stellar associations, but surprises and discoveries are not exhausted. Metaphorically, one can say that for a long time astronomers will follow the path illuminated by stellar associations.
Markarian survey and Markarian galaxies
Authors:   NAS RA V. Ambartsumian Byurakan Astrophysical Observatory (BAO), Armenia, Mickaelian A. M.
Published: January 2022

Markarian survey (or the First Byurakan Survey, FBS) was the first systematic survey for active galaxies and was a new method for search for such objects. Until now, it is the largest objective prism survey of the sky (17,000 deg2). It was carried out in 1965-1980 by B. E. Markarian and his colleagues and resulted in discovery of 1517 UV-excess (Markarian) galaxies. They contain many active galaxies, as well as powerful gamma-, X-ray, IR and radio sources (Mrk 180, 231, 421, 501, etc.), BCDGs (Mrk 116) and interacting/merging systems (Mrk 266, 273, etc.). They led to the classification of Seyfert galaxies into Sy1 and Sy2 and the definition of Starbursts (SB). Several catalogs of Markarian galaxies have been published (Bicay et al., 1995, Markarian et al., 1989, Mazzarella & Balzano, 1986, Petrosian et al., 2007) and they are accessible in all corresponding databases. Markarian survey also served as a basis for search for UVX stellar objects (including QSOs and Seyferts), late-type stars and optical identification of IR sources. At present the survey is digitized and DFBS database is available. We review the main characteristics of the Markarian survey, its comparison with other similar surveys and the importance of Markarian galaxies in modern astrophysics.
ADDITIVE MANUFACTURING AND VULCANIZATION OF CARBON BLACK–FILLED NATURAL RUBBER–BASED COMPONENTS
Authors: Leineweber Sebastian , Sundermann Lion , Bindszus Lars , Overmeyer Ludger , Klie Benjamin , Wittek Heike , Giese Ulrich
Published: January 2022

Additive manufacturing of thermoplastics or metals is a well-approved sustainable process for obtaining rapidly precise and individual technical components. Except for crosslinked silicone rubber or thermoplastic elastomers, there is no method of additive manufacturing of elastomers. Based on the development of the additive manufacturing of elastomers (AME) process, the material group of rubber-based cured elastomers may gain first access to the process field of three-dimensional (3D) printing. Printing and crosslinking of rubber is separated into two steps. In the first step, printing is realized by extrusion of the rubber by using a twin-screw extruder, which works according to the derived fused-filament-fabrication principle. In the second step, the component is vulcanized in a high-pressure hot-air autoclave. Because of the plastic flow behavior of non–crosslinked rubber materials, a thermoplastic shell is probably needed to maintain the geometry and position of the additively manufactured rubber. In this way, one layer of thermoplastic and one layer of rubber are printed alternatingly until the component is finished. Afterward, the manufactured binary component is placed in an autoclave to obtain the elastomer after vulcanization under a hot-air and high-pressure atmosphere. Then, the thermoplastic shell is removed from the elastomer and can subsequently be recycled. As compared with conventional thermoplastics, the high viscosity of rubber during processing and its instable shape after extrusion are challenging factors in the development of the AME. This contribution will show a modified 3D printer; explain the printing process from the designed component, via shell generation, to the vulcanized component; and show first printed components.
Preparation of Silica-4-(2-pyridylazo) Resorcinol Chelator for Solid Phase Extraction of Transition Metals from Groundwater
Authors: Awadh O AlSuhaimi Awadh O AlSuhaimi
Published: January 2022

The determination of trace heavy metals in environmental samples requires reliable sample preparation method to improve instrument detectability or minimize matrices effect. Solid phase extraction (SPE) using metal chelators is an attractive approach for the selective extraction of trace metals from aqueous media in various applications. In this work, chelating resin was prepared by chemical attachment of the chelating moiety, 4-(2-pyridylazo)resorcinol(PAR) onto silica gel using an eco-friendly chemical transformation. The successfulness of the chemical modification was confirmed by Fourier transform infrared (FTIR), elemental analysis (EA) and scanning electron microscopy (SEM). The separation/preconcentration conditions of analytes including exchange capacity, effect of pH, adsorption kinetics and isotherm for metal extraction, were investigated.At optimum conditions, the resin loading capacity for the metals Cu2+, Ni2+ and Mn2+were 0.121, 0.132 and 0.124 mmolg-1in that order. The material performance as SPE sorbent for trace metals has been assessed usingCu2+, Ni2+ and Mn2+ in certified reference natural water sample, and real groundwater samples from Almedinah AlMunawarah. The accurate and precise results verify the resin appropriateness for matrix removal/ preconcentration prior to the analysis of heavy metals from this type of matrices.
Phytochemical Analysis and Anthelmintic Activity of Salsola imbricata
Authors: Muhammad Ajaib Muhammad Ajaib , Saleha Farooq Saleha Farooq , Khalid Mohammed Khan Khalid Mohammed Khan , Shahnaz Perveen and Shazia Shah Shahnaz Perveen and Shazia Shah
Published: January 2022

Phytochemical investigation and anthelmintic activity of Salsola imbricata Forssk was carried out. Phytochemical analysis showed the presence of anthraquinones, reducing sugar, tannins, saponins, flavonoids, alkaloids and cardiac glycosides. Analysis of anthelmintic activity exhibited that bark extract of S. imbricata is more potent than fruit extract. Minimum time for paralysis and death of worms (9 and#177; 0.6 and 13 and#177; 0.2 min.) was taken by chloroform extract of bark at concentration of 100 mg/mL whereas fruit extract of chloroform was taken minimum time for paralysis and death of worms (10 and#177; 1.1 and 16 and#177; 0.1min.) at concentration of 100 mg/mL.
Removing of the Dye Pollutant Acid Red 1 from Contaminated Waters by Electrocoagulation Method Using a Recirculating Tubular Reactor with Punched Anode
Authors: Mohsen Garajehdaghi and Kambiz Seyyedi Mohsen Garajehdaghi and Kambiz Seyyedi
Published: January 2022

In the present study the removal of Acid red 1 (AR1), as a pollutant of contaminated waters, was investigated by the electrocoagulation method using a recirculating tubular reactor with punched anode. The role of the parameters affecting removal efficiency including current density, electrolysis time, electrolyte concentration and type, pH, the flow rate of the solution, and dye concentration was studied. Spectrophotometric results indicated that for 2500 ml of the dye solution containing 30 mg L-1 AR1 more than 95% of the dye was removed under the following conditions: current density of 1.3 mA cm-2, electrolysis time of 20 min, pH of 6, electrolyte dosage of 0/08 g L-1 , and the flow rate of 2 L min-1. Results showed that with an increase the electrolyte concentration and current density, color removal efficiency increases. Increasing of the flow rate of solution in the reactor due to decrease the retention time, decreases the removal efficiency. According to nature of electrocoagulation process, neutral range of pH is suitable for decolorization process.
Recent Progress in the Application of Ionic Liquids in Electrochemical Oxidation and Reduction
Authors: Nan Yao and Yu Lin Hu Nan Yao and Yu Lin Hu
Published: January 2022

Electrochemical oxidation and reduction, with clean power, are key to energy conversion and storage. For example, electrochemical oxidation is a determining step for fuel cells, combination of electrochemical oxidation and reduction can form a metal-air battery. Electrochemical oxidation and reduction make significant contributions to prepare valuable chemicals directly and improve yield efficiency and reduce the three wastes, which have become one of the green methodologies. Ionic liquids have attracted increasing attentions in the area of electrochemistry due to their significant properties including good chemical and thermal stability, wide liquid temperature range, considerable ionic conductivity, nonflammability, broad electrochemical potential window and tunable solvent properties. Up to now, abundant studies of ionic liquids have reported for their practical applications for electrochemical reactions. This review covers recent studies on the applications of ILs as green and universal replacements for the traditional reagents in electrochemical oxidation and reduction. The adaptabilities of ILs in these reactions are predicted as a solution to the problems of conventional electrochemical processes and to become a powerful method in electrochemical oxidation and reduction.
Grafting of Chitosan: Structural, Thermal and Antimicrobial Properties
Authors: Nevin Cankaya Nevin Cankaya
Published: January 2022

In this study, some new chitosan materials were synthesized by the grafting of chitosan with the monomers such as 1-vinylimidazole (VIM), methacrylamide (MAm) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). First of all, chitosan methacrylate was prepared by esterification of primary -OH group with methacryloyl chloride a 25.13% yield by mole. The monomers were grafted into chitosan methacrylate via free radical polymerization using 2,2and#39;-Azobisisobutyronitrile as an initiator in N,N-dimethylformamide. The graft copolymers were characterized by FT-IR spectra and elemental analysis. Thermal stabilities of the graft copolymers were determined by TGA (thermo gravimetric analysis) method. The synthesized chitosan methacrylate and its graft copolymers were tested for their antimicrobial activity against bacteria and yeast.
An Improved Method of Synthesis of per-6-deoxy-6-iodo-β-cyclodextrin
Authors: Suomin Feng Suomin Feng , Jiaxing Feng Jiaxing Feng , Guangcan Xu Guangcan Xu , Jiang Liu Jiang Liu , and Yongmin Zhang and Yongmin Zhang
Published: January 2022

A number of per-6-substituted-6-deoxy-β-cyclodextrin derivatives have been synthesized for many years, of them, per-6-deoxy-6-iodo-β-cyclodextrin is of great importance in supramolecular chemistry. By reviewing all published papers related to synthesis of per-6-deoxy-6-iodo-β-cyclodextrin and combining with our experimental verification, this work has reported an improved method of synthesis of per-6-deoxy-6-iodo-β-cyclodextrin. The approach mainly uses adding a certain amount of methanol instead of removing DMF before adjusting pH. We think this project is simple, efficient, high repeatable and suitable for large-scale preparation, superior even to all the previously reported methods. The synthesis of bromo, chloro substituted -per-6-β-CD may also refer to this improved method. At the same time, the detailed introduction of operation process and precautions will serve as a reference and guidance to the beginner who will engage in the study on the chemical synthesis reaction of sugar and cyclodextrin.
Microwave Absorbing Properties of Polyaniline-NiFe2O4: V composites
Authors: Ethem Ilhan SAHIN and Selcuk PAKER Mesut KARTAL Ethem Ilhan SAHIN and Selcuk PAKER Mesut KARTAL
Published: January 2022

In this study, vanadium doped NiFe2O4 was produced by using mixed oxide technique. The NiFe2-xVxO4 composition was synthesized and x was selected as 0.1, 0.2 and 0.3, respectively. The single-phase Ni ferrite was produced after sintering at 1100and#176;C for 4h. X-Ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were performed for structural analysis. The results of the structural analysis indicated that the second phase did not form in NiFe2-xVxO4. Additionally, the polyaniline-vanadium doped NiFe2O4 composites were produced by hot pressing using the compositions of NiFe1.9V0.1O4.1, NiFe1.8V0.2O4.2, NiFe1.7V0.3O4.3, and aniline. The weight ratios of vanadium-doped nickel ferrite and aniline were 1:1 and 1:3, respectively. Epoxy resin was used to produce microwave-absorbing composites. The fabricated composites were characterized by using Fourier transform infrared spectroscopy (FTIR). Furthermore, the magnetic properties of the fabricated composites were investigated by using a vibrating sample magnetometer (VSM). The microwave absorbing performances of the polyaniline-NiFe2O4: V composites were investigated by reflectivity in 0–8 GHz, using a two–port vector network analyzer. A minimum of -42.17 dB reflection performance was obtained in 7.02 GHz at the thickness of 2.0 mm. This reflection performance can be modulated simply by controlling the content of polyaniline in the samples for the required frequency bands.
Production of Microbial Biomass Protein by Arachniotus ruber using Banana Peel and its Biological Evaluation in Broiler Chicks
Authors: Muhammed Shiraz Yasin Muhammed Shiraz Yasin , Shagufta Saeed Shagufta Saeed , Muhammed Tayyab Muhammed Tayyab , Abu Saeed Hashmi Abu Saeed Hashmi , Ali Raza Awan Ali Raza Awan , Sehrish Firyal and Rahat Naseer Sehrish Firyal and Rahat Naseer
Published: January 2022

The major issue of the developing countries, i.e. malnutrition, results from intake of diet deficient in proteins. The problem can be resolved by searching for novel and cheap protein sources. Bioconversion of inexpensive fruit waste to an economical product like microbial protein can be useful in the present situation. The aim of the present study was to enhance the crude protein content of banana peels by Arachniotus ruber under solid state fermentation for utilization in broiler feed. Different physicochemical parameters were optimized to increase the yield. Biological evaluation was carried out by replacing 25 and 50% of sunflower meal in broiler feed with the biomass protein. Different parameters e.g.: weight gain, feed efficiency, feed conversion ratio and protein efficiency ratio were recorded. The optimum conditions to achieve highest amount of crude protein (15.8%) on fermentation of banana peels was 1:1.5 substrate water ratio, 2mL inoculum volume, pH 4 after 72 hours of incubation time. Addition of glucose (0.5%), corn steep liquor (0.25%) and MgSO4 (0.05%) enhanced the yield. Outcome of the study revealed that biomass protein produced, can replace up to 50% of the protein supplied by sunflower meal with the positive effect on weight gain of the chicks.
Synthesis and DFT Quantum Chemical Calculations of Novel Pyrazolo[1,5-c]pyrimidin-7(1H)-one Derivatives
Authors: Murat Saracoglu Murat Saracoglu , Zulbiye Kokbudak Zulbiye Kokbudak , Zeynep imen and Fatma Kandemirli Zeynep imen and Fatma Kandemirli
Published: January 2022

In this study, a convenient procedure for the preparation of pyrazolo[1,5-c]pyrimidin-7(1H)-one derivatives is described. The new pyrazolo[1,5-c]pyrimidin-7(1H)-one derivatives (2a, b) were synthesized from the cyclocondensation reaction of the compounds 1-amino-5-(4-methoxybenzoyl)-4-(4-methoxyphenyl)pyrimidin-2(1H)-one (1a) and 1-amino-5-(4-methylbenzoyl)-4-(4-methylphenyl)pyrimidin-2(1H)-one (1b) with α-chloroacetone. The structures of the compounds (2a, b) were characterized by elemental analysis, FT-IR, 1H-NMR and 13C-NMR spectroscopic techniques. In addition to experimental study in order to find molecular properties, quantum-chemical calculations of the new pyrazolo[1,5-c]pyrimidin-7(1H)-one derivatives (2a, b) were carried out by using DFT/B3LYP method with the 6-311G(d,p) and 6-311++G(2d,2p) basic sets. Quantum chemical features such as HOMO, LUMO, HOMO-LUMO energy gap, chemical hardness, chemical softness, electronegativity, chemical potential, dipole moment etc. values for gas and solvent phase of neutral molecules were calculated and discussed.
Synthesis and Crystal Structures of 3,6-diacetylated C24 epimeric 20(R)-Ocotillol-Type Saponins
Authors: Juan Liu Juan Liu , Wen Zhi Wang Wen Zhi Wang , Jia Zhen Wang Jia Zhen Wang , Gui Ge Hou Gui Ge Hou , Qing Guo Meng Qing Guo Meng
Published: January 2022

(20R,24R)-epoxy-dammar-3β,6α,12β,25-tetraol (1) and (20R,24S)-epoxy- dammar-3β, 6α,12β,25-tetraol (2) have been synthesized from 20(R)-protopanaxatriol with same polarity. In order to obtain optically pure 1 and 2, (20R,24R)-3,6-diacetyl- 20,24-epoxydammar-3β,6α,12β,25-tetraol (3) and (20R,24S)-3,6-diacetyl-20,24- epoxydammar-3β,6α,12β,25-tetraol (4) were designed and prepared to enhance the polarity difference of C24 epimers. Two suitable crystals of 3 and 4 were obtained and their structures were determined by 1H NMR, 13C NMR, HR-MS and X-ray single-crystal diffraction. The results indicated that the C-24 configuration of 3 and 4 are R-form and S-form, respectively. 3 has two intramolecular hydrogen bond. While there is only one in 4 and the crystal stacking displays that it generates a right-handed helically chiral channel viewing from the crystallographic b axis via classical O–H•••O intermolecular hydrogen bond.
Orodispersible Films of an Antipsychotic Drug: Development and Physicochemical Characterization
Authors: Muhammad Naeem Aamir Muhammad Naeem Aamir , Aneela Manzoor Aneela Manzoor , Hina Hussain Hina Hussain , Zeeshan Javaid Zeeshan Javaid , Tariq Mahmood Tariq Mahmood , Khizar Abbas Khizar Abbas , and Akhtar Rasul and Akhtar Rasul
Published: January 2022

To deliver maximum amount of paroxetine in shortest duration of time, the orodispersible films (ODF) were formulated and tested for their suitability as a carrier system. ODF were prepared by using hydroxypropyl methylcellulose and polyvinyl alcohol and different superdisintegrants at a specific proportion. The newly developed ODF were subjected to characterization for folding endurance, weight variations, thickness, disintegration time, drug release pattern and drug content. The surface morphology of orodispersible film was examined by means of scanning electron microscope. Moreover physical compatibility between the drug and excipients was guaranteed in the orodispersible film by Fourier transform infrared spectroscopy. It was found that all films prepared were transparent, smooth and elegant in appearance. ODF showed good folding endurance, uniform thickness, weight and drug content. The surface pH of all orodispersible film was found to be neutral and they disintegrate within few seconds. FTIR spectroscopy supported compatible among all excipients and they can be used together in formulation. It was concluded that stable paroxetine orodispersible films can be made by solvent casting technique with ultrafast dissolution rate.
Colonization Frequency, Endophytic Infection Rate and Bioactivities of Microbes of Desert Medicinal Plants
Authors: Suriya Rehman Suriya Rehman , Mohammad Azam Ansari Mohammad Azam Ansari , Abdullah Buhaimed Abdullah Buhaimed , Fatemah Ibrahim and Adil Gani Fatemah Ibrahim and Adil Gani
Published: January 2022

The present study, provides an information on the colonization of endophytic fungi in three desert medicinal plants, i.e. Artemesia sieberii, Citrillus colocynthis and Moringa peregrine, along with their biological activities. The highest colonization frequency (CF) and endophytic infection rate (EIR), was observed in C colocynthis (87.5% andamp; 81.25%), respectively, followed by A. sieberii (62.5 andamp; 56.25%) and M. peregrine (37.5 andamp; 31.25%), respectively. The colonization frequency was highest in leaves, when compared to the stem parts. Among the screened isolates, three selected endophytes, (ART 7) from A. sieberii, (CTC11) from C colocynthis and (MOP5) from M. peregrine, with the zone of inhibition greater than 12 mm, were further evaluated for minimum inhibitory concentration (MIC). MIC against gram positive was ranging from 125 to 1000 and#181;g/ml and 250 to 2000 and#181;g/ml against gram negative. Thus, gram-positive strains, were found to be more susceptible. CTC11 from C. colocynthis showed fairly better MIC, against both gram positive and gram-negative organisms, ranging from 125 to 500 and#181;g/ml and 250 to 1000 and#181;g/ml, respectively. The total phenolic content was determined, (ART 7) from A. sieberii, was found to possess a high phenolic content (12.6 and#177; 0.16). Therefore, the significant antimicrobial activity, reducing power and total phenolic content of the isolates, suggests the use of endophytes of desert medicinal plants, as a rich and reliable source of industrially important compounds.
Performance Enhancement of Polymeric Blend Membranes Incorporation of Methyl Diethanol amine for CO2/CH4 Separation
Authors: Asim Mushtaq Asim Mushtaq , Hilmi Mukhtar and Azmi Mohd Shariff Hilmi Mukhtar and Azmi Mohd Shariff
Published: January 2022

For efficient gas separation the membrane technology is rapidly growing day by day and it is more economical and effectual than past technologies. The main objective of this study is to synthesis polymer blend membranes (PBM) using glassy polysulfone (PSU) and rubbery polyvinyl acetate (PVAc) with the addition of methyl diethanol amine for removal of CO2 from CH4. The PBM were developed by varying the composition of PVAc ranging from 5 to 20 wt% with 80 to 100 wt% PSU in DMAc solvent. The amine composition was added to the blend and kept at 10 wt%. The present of MDEA in the PBM had increased the CO2 permeance as compare with the based polymer membranes. However as the operating pressure increased from 2 to 10 bar, the PBM (PSU95%/PVAc5%) with MDEA was found to increase significantly the permeance of CO2, hence increasing the separation factor from 9.980.02 to 30.190.49. EPBM was found a very promising to be used for CO2/CH4 separation.
Graphene Nanoplates Filled Nylon 6,6 Nanocomposites, Morphological, Thermal, Mechanical and Solvent Uptake Study
Authors: Khalid Saeed Khalid Saeed , Tariq Shah and Ahmad Hassan Tariq Shah and Ahmad Hassan
Published: January 2022

Effect of graphene nanoplates (GNPs) on the properties of Nylon 6,6 (Nyl 6,6) is investigated in present study. The morphological studies presented that the GNPs were dispersed inside the Nyl 6,6 matrix. The thermo gravimetric analysis (TGA) illustrated that the thermal degradation of nanocomposites samples were started at the range of 350-393 oC, which was appreciably higher than neat Nyl 6,6 (360 oC). The differential scanning calorimetry (DSC) analyses revealed that the crystallization temperature (Tc) of GNPs/Nyl 6,6 increased as increased the addition of GNPs, which might be due to the nucleation effect of GNPs. The mechanical properties of Nyl 6,6 was enhanced by incorporation of GNPs upto the addition of an optimal quantity of filler (5%wt GNPs) into the polymer matrix. The stress yield and Young’s modulus of 5%wt GNPs/Nyl 6,6 was 96.79 and 1.54, N/nm2, respectively. Both Nyl 6,6 and nanocomposites samples were also used for the adsorption of Neutral red chloride (NRC) dye, which significantly remove the dye from the aqueous solution. The neat nylon 6,6 and GNPs (5 and 10 wt%)/Nyl 6,6 adsorbed about 88.49, 93.15, and 93.60% within 2 h, respectively.
Effect of MgO Addition on the Properties of Ni/Al2O3 and Its Catalytic Activity in Hydrogenation of N-(2`,3`-dimethoxy benzyl)-3,4-dioxy-methylene-phenylethylamine
Authors: Guosheng Wang Guosheng Wang , Xinxin Zhao and Siyu Han Xinxin Zhao and Siyu Han
Published: January 2022

the nickel based alumina-supported catalysts modified or promoted by magnesia were prepared by wet impregnation and successfully used for hydrogenation of N-(2`,3`-dimethoxy benzyl)-3,4-dioxy-methylene-phenylethylamine, the 20Ni-6MgO/74Al2O3 samples exhibits the highest BET surface area, the largest pore volume, and the largest pore diameter in all of the samples such as Ni/Al2O3 and 20Ni-xMgO(80-x)Al2O3 excepted the highest BET surface area of Ni/Al2O3. the average pore diameter of the 20Ni-6MgO/74Al2O3 samples were two times as large as Ni/Al2O3, it was indicated that the function of expanding role or the mesoporosity was increased by addition of MgO, and MgO might be regarded as pore-enlarge agent for the bare Al2O3 support and benefit for the transport of large molecules reactants and products The weak formation of MgO-Al2O3 and MgO-NiO solid solution as a result of competing interaction of MgO with Al2O3 support and NiO precursors restrained the strong interaction of NiO species with Al2O3 support, which favored the dispersion of active Ni centers and improved the reducible degree of NiO species on the surface of the catalysts. The improvement of basicity or the decrease in the number of acid centers in the catalysts avoid the secondary reactions, and subsequently resulted in high catalytic activity. The utilization of meso-porous 20Ni-6MgO/74Al2O3 for catalytic hydrogenation of N-(2`,3`-dimethoxy benzyl)-3,4-dioxy-methylene-phenylethylamine(Shiff’s base) with the highest selectivity of 99.70% and yields of 94.36% implied that the instead of Raney Ni was feasible.
Synthesis and DFT Quantum Chemical Calculations of 2-Oxopyrimidin-1(2H)-yl-Urea and Thiorea Derivatives
Authors: Murat Saracoglu Murat Saracoglu , Zulbiye Kokbudak Zulbiye Kokbudak , Esra Yalcin and Fatma Kandemirli Esra Yalcin and Fatma Kandemirli
Published: January 2022

A series of the new 2-oxopyrimidin-1(2H)-yl-urea (3a-c) and thiourea (4a-d) derivatives were synthesized by the reaction of arylisocyanates (2a-c) or arylisothiocyanates (2d-g) and the 1-amino-5-(4-methoxybenzoyl)-4-(4-methoxyphenyl)pyrimidin-2(1H)-one (1). The structures of the compounds 3a-c and 4a-d were characterized by elemental analysis, FT-IR, 1H and 13C-NMR spectroscopic techniques. In addition to experimental study in order to find molecular properties, quantum-chemical calculations of the synthesized compounds were carried out by using DFT/B3LYP method with basis set of the 6-311G(d,p). Quantum chemical features such as HOMO, LUMO, HOMO-LUMO energy gap, Ionization potential, chemical hardness, chemical softness, electronegativity, chemical potential, dipole moment etc. values for gas and solvent phase of neutral molecules were calculated and discussed.
Study on Solvent Extraction Behavior of Rubidium by t-BAMBP-Sulphonated Kerosene System from Salt Lake Brine
Authors: Amin Bao and Qian zhiqiang Amin Bao and Qian zhiqiang
Published: January 2022

The system of 4-tert-butyl-2-(α-methyl benzyl) phenol (t-BAMBP) and sulphonated kerosene (SK) solution was used to extract rubidium from Salt Lake Brine which has been removed the Mg2+ by precipitatation method. Several experimental parameters such as the concentration of t-BAMBP, hydroxide ion and stripping acid, the volume ratio of organic phase to aqueous extraction phase (O/A) and extraction stage were investigated. The obtained results showed that extraction efficiency of Rb+can reach 96% after five -stage, and the stripping efficiency of Rb+ can reach 99% after two-stage. And the extraction equilibrium constant K is calculated to be 25.85, enthalpy change is -20.79 kJ mol-1 and the separation factor of five-stage extraction is 71.77. The system of t-BAMBP and SK could be fully regenerated by water and showed no significant decrease after ten extraction-stripping cycles, indicating that the extractant was stable and reusable. The presence of co-existing ions do not interfere with rubidium extraction, indicating the high selectivity of t-BAMBP and SK for rubidium ion. The method provides an idea for exploitation and utilization rubidium and has the important economically significant for industrialization extraction rubidium.