bluuebunny/crossref_metadata_2025 huggingface dataset:
Cobalt Metal ALD: Understanding the Mechanism and Role of Zink Alkyl Precursors as Reductants for Low Resistivity Co Thin Films
Authors: Zanders David , Liu Ji , Obenlüneschloß Jorit , Bock Claudia , Rogalla Detlef , Mai Lukas , Nolan Michael , Barry Sean , Devi Anjana
Published: March 2021

In this work, we report a new and promising approach towards the atomic layer deposition (ALD) of metallic Co thin films. Utilizing the simple and known CoCl2(TMEDA) (TMEDA = N,N,N’,N’-tetramethylethylenediamine) precursor in combination with the intramolecularly stabilized Zn aminoalkyl compound Zn(DMP)2 (DMP = dimethylaminopropyl) as auxiliary reducing agent, a thermal ALD process is developed that enables the deposition of Zn free Co thin films. ALD studies demonstrate the saturation behavior of both precursors, linearity in dependency of the applied number of cycles as well as investigations of the temperature dependency of film growth in a regime of 140 - 215 °C. While the process optimization is carried out on Si with native oxide, additional growth studies are conducted on Au and Pt substrates. This study is complemented by initial reactivity and suitability tests of several potential Zn alkyl reducing agents. For the CoCl2(TMEDA) - Zn(DMP)2 combination, these findings allow to propose a series of elemental reaction steps hypothetically leading to pure Co film formation in the ALD process whose feasibility are probed by a set of DFT calculations. The DFT results show that for reactions of the precursors in the gas phase and on Co(111) substrate surfaces, a pathway involving C-C coupling and diamine formation through reductive elimination of an intermediate Co(II) alkyl species is preferred. Co thin films with an average thickness of 10 - 25 nm obtained from the process are subjected to thorough analysis comprising AFM, SEM, RBS/NRA as well as depth profiling XPS. Resistivity measurements for ~ 22 nm thick films grown on a defined SiO2 insulator layer yield highly promising values in a range of 15 - 20 μΩ cm without any after treatment.
PhotoPhage: A Virus-based Photothermal Therapeutic Agent
Authors: Shahrivarkevishahi Arezoo , Luzuriaga Michael A. , Herbert Fabian C. , Tumac Alisia C. , Brohlin Olivia R. , Wijesundara Yalini H. , Benjamin Candace , Lee Hamilton , Parsamian Perouza , Gassensmith Jeremiah J.
Published: March 2021

ABSTRACT: Virus like particles (VLPs) are non-infectious multifunctional nanocarriers with the pathogenic-like architecture of viruses. They can serve as a safe platform for precise functionalization and immunization, which provides benefits in a wide range of biomedical applications. In this work, we describe the development of novel immunophotothermal agent for combinatorial photothermal ablation and immunotherapy based on VLP of bacteriophage Qβ. The design was based on covalent conjugation of 212 water soluble near-infrared absorbing croconium dyes to lysine residues located on the surface of Qβ, which turned it to a powerful NIR-absorber with photothermal efficiencies exceeding that of gold nanostructures. This PhotoPhage system generates heat upon 808 nm NIR laser radiation and causes significant cellular cytotoxicity that prevents the progression of primary tumors in mice. It is found that PhotoPhage not only acts as a PTT agent that initiates anti-tumor immune response, but also simultaneously acts as an immunoadjuvant that promotes maturation of dendritic cells, triggers T lymphocyte cells (CD4+, CD8+) and reduces suppressive T regulatory cells leading to effective suppression of primary tumors, reducing lung metastases, and increasing survival time.
A Convenient and Cost Efficient Route Suitable for “One-Pot” Synthesis of Molnupiravir
Authors: Hu Tianwen , Xie Yuanchao , Liu Yin , Xue Haitao , Zhu Fuqiang , A. Aisa Haji , Shen Jingshan
Published: March 2021

Herein, we reported a convenient and cost efficient one-pot synthesis of molnupiravir from cytidine. This method utilized N,N-dimethylformamide dimethyl acetal (DMF-DMA) as an extraordinary protecting agent to achieve site specific esterification at 5’-hydroxyl group of the nucleoside easily, and afforded this promising drug candidate (purity up to 99%, HPLC a/a) in 70% overall yield without chromatography purification, which is superior to the existing methods in aspect of the yield, the cost and the operation, and shows great potential value for commercial production. Furthermore, this excellent protecting agent was also successfully used in the synthesis of remdesivr from its parent nucleoside with a high total yield (76%).
Prediction of Drug-Target Binding Kinetics for Flexible Proteins by Comparative Binding Energy Analysis
Authors: Nunes Alves Ariane , Ormersbach Fabian , Wade Rebecca , Nunes-Alves Ariane
Published: March 2021

There is growing consensus that the optimization of the kinetic parameters for drug-protein binding leads to improved drug efficacy. Therefore, computational methods have been developed to predict kinetic rates and to derive quantitative structure-kinetic relationships (QSKRs). Many of these methods are based on crystal structures of ligand-protein complexes. However, a drawback is that each protein-ligand complex is usually treated as having a single structure. Here, we present a modification of COMparative BINding Energy (COMBINE) analysis, which uses the structures of protein-ligand complexes to predict binding parameters. We introduce the option to use multiple structures to describe each ligand-protein complex into COMBINE analysis andapply this to study the effects of protein flexibility on the derivation of dissociation rate constants (koff) for inhibitors of p38 mitogen-activated protein (MAP) kinase, which has a flexible binding site. Multiple structures were obtained for each ligand-protein complex by performing docking to an ensemble of protein configurations obtained from molecular dynamics simulations. Coefficients to scale ligand-protein interaction energies determined from energy-minimized structures of ligand-protein complexes were obtained by partial least squares regression and allowed the computation of koff values. The QSKR model obtained using single, energy minimized crystal structures for each ligand-protein complex had a higher predictive power than the QSKR model obtained with multiple structures from ensemble docking. However, the incorporation of protein-ligand flexibility helped to highlight additional ligand-protein interactions that lead to longer residence times, like interactions with residues Arg67 and Asp168, which are close to the ligand in many crystal structures, showing that COMBINE analysis is a promising method to design leads with improved kinetic rates for flexible proteins.
DNA-Directed Patterning for Versatile Validation and Characterization of a Lipid-Based Nanoparticle Model of SARS-CoV-2
Authors: Kozminsky Molly , Carey Thomas , Sohn Lydia L.
Published: March 2021

Lipid-based nanoparticles have risen to the forefront of the COVID-19 pandemic—from encapsulation of vaccine components to modeling the virus, itself. Their rapid development in the face of the volatile nature of the pandemic requires high-throughput, highly flexible methods for characterization. DNA-directed patterning is a versatile method to immobilize and segregate lipid-based nanoparticles for subsequent analysis. DNA-directed patterning selectively conjugates oligonucleotides onto a glass substrate and then hybridizes them to complementary oligonucleotides tagged to the liposomes, thereby patterning them with great control and precision. The power of this method is demonstrated by characterizing a novel recapitulative lipid-based nanoparticle model of SARS-CoV-2 —S-liposomes— which present the SARS-CoV-2 spike (S) protein on their surfaces. Patterning of a mixture of S-liposomes and liposomes that display the tetraspanin CD63 into discrete regions of a substrate is used to show that ACE2 specifically binds to S-liposomes. Importantly, DNA-directed patterning of S-liposomes is used to verify the performance of a commercially available neutralizing antibody against the S protein. Ultimately, the introduction of S-liposomes to ACE2-expressing cells demonstrates the biological relevance of DNA-directed patterning. Overall, DNA-directed patterning enables a wide variety of custom assays for the characterization of any lipid-based nanoparticle.
High-Throughput Computational Screening of Cubic Perovskites for Solid Oxide Fuel Cell Cathodes
Authors: Tezsevin Ilker , Sanden M.C.M. van de , Er Süleyman
Published: March 2021

It is a present-day challenge to design and develop oxygen permeable solid oxide fuel cell (SOFC) electrode and electrolyte materials that operate at low temperatures. Herein, by performing high-throughput density functional theory (HT-DFT) calculations, oxygen vacancy formation energy, Evac, data for a pool of all-inorganic ABO3 and AI0.5AII0.5BO3 cubic perovskites is generated. Using Evac data of perovskites, the area-specific resistance (ASR) data, which is related to both oxygen reduction reaction activity and selective oxygen ion conductivity of materials, is calculated. Screening a total of 270 chemical compositions, 31 perovskites are identified as candidates with properties that are in between state-of-the-art SOFC cathode and oxygen permeation components. In addition, an intuitive approach to estimate Evac and ASR data of complex perovskites solely by using the easy-to-access data of simple perovskites is shown, which is expected to boost future explorations on perovskite material search space for genuinely diverse energy applications.
Integrated Material and Process Evaluation of Metal-Organic Frameworks Database for Energy-efficient SF6/N2 Separation
Authors: Cha Jaehoon , Ga Seongbin , LEE Seung-Joon , Nam Soomyung , Bae Youn-Sang , Chung Yongchul
Published: March 2021

In this work, we proposed multi-scale screening, which employs both molecular and process-level models, to identify high-performing MOFs for energy-efficient separation of SF$_6$ from SF$_6$ and N$_2$ mixture. Grand canonical Monte Carlo (GCMC) simulations were combined with ideal adsorption process simulation to computationally screen 14,000 metal-organic frameworks (MOFs) for adsorptive separation of SF$_6$ \/ N$_2$. More than 150 high-performing MOFs were identified based on the results from GCMC simulations at the pressure and vacuum swing conditions, and subsequently evaluated using the ideal adsorption process simulation. High-performing MOFs selected for the VSA conditions are able to achieve the 90 \% target purity level of SF$_6$ but none of the selected MOFs for PSA conditions could. Cascade PSA configuration was proposed and adopted to improve the purity level of the separated SF$_6$. Cascade PSA configuration was also adopted to improve the purity. In the pump efficiency scenarios of 80, 20, and 10 \%, the VSA and cascade PSA cases were compared, which concluded 10 \% scenario prefers the PSA case whereas the VSA case is favored in the others. Top-performing MOFs identified from the multi-scale computational approach were found to be able to produce 90\% purity SF$_6$ with 0.10 - 0.4 and 0.5 - 1.4 MJ per kg of SF$_6$ for VSA and PSA, respectively.
Metal-Free Fenton-like Photocatalysts Based on Covalent Organic Frameworks
Authors: Liao Qiaobo , Ke Can , Wang Dongni , Zhang Yiying , Han Qingwen , Zhang Yifan , Xi Kai
Published: March 2021

The Fenton reaction is one of the most efficient and widely used advanced oxidation processes for remediating the ever-growing water pollution. Metal-free photocatalysts for Fenton-like reactions have gathered enormous scientific interest for their advantages including board pH operation range and high stability. Herein, we demonstrate a metal-free covalent organic framework (COF)-based standalone photocatalyst with superior reactivity and reusability for Fenton-like reactions at acid and neutral pH solutions, which can be attributed to its large porosity, high density of the photoactive triazine moiety, vertical π arrays formed by eclipsed layer stacking and the β‑ketoenamine linkage. Our experiments showed that the photocatalyst can absorb visible light effectively for activation of H2O2, producing abundant reactive oxygen species including superoxide radical (O2·-), hydroxyl radical (·OH), and singlet oxygen (1O2) for oxidizing organic pollutants. This work not only provides an efficient metal-free photocatalyst for Fenton-like reactions, but also paves the way for COFs towards advanced oxidation processes, opening up the possibilities to their future applications in industry.
Facile and Selective Conversion of Levulinic Acid into γ-Valerolactone by Low-cost Fe and Ni Catalysts in Water
Authors: Chen Xi , Ma Zhuang , Yan Wubin , Yao Guodong , li qiuju , Jin Binbin , Guo Yaling , wang yudi
Published: March 2021

Renewable chemical production from biomass is desirable for the sustainable development of the society. Levulinic acid (LA) is a common biomass-derived building block that furnishes a suitable source to produce the industrially valuable γ-valerolactone (GVL). In this work, a low-cost, green and effective catalytic system was developed to transform LA into GVL in water by using Fe and Ni, in which the hydrogen source was provided by water splitting. The Fe primarily functioned as the reductant that transformed into Fe3O4 species after the reaction, while Ni played the major catalytic role to promote selective LA hydrogenation into GVL. After optimizations, the GVL yield reached the highest of 99% within 2-3 h at relatively low hydrothermal temperature of 230-250 °C. The recycling tests of Ni has suggested negligible decrease of product yield after four runs. This study establishes a green, facile and eco-friendly approach to synthesize GVL from biomass-derived LA.
Time-Dependent Influence of High Glucose Environment on the Metabolism of Neuronal Immortalized Cells
Authors: Colombaioni Laura , Campanella Beatrice , Nieri Riccardo , Onor Massimo , Benedetti Edoardo , Bramanti Emilia
Published: March 2021

In this work the effect of glucose concentration on the metabolome of living hippocampal HN9.10e neurons was studied. This cell line represents a reliable, in vitro model of one of the most vulnerable regions of central nervous system. Targeted metabolites were analyzed in the cell culture medium by two direct methods, namely liquid chromatography – diode array detection and headspace – solid phase micro extraction – gas chromatography – mass spectrometry. Twenty-two metabolites were simultaneously identified and quantified in the growth medium of the cells, treated with 25, 50 or 75 mM glucose, sampled along 8 days to mimic a prolonged hyperglycemia. The results of statistical analysis showed the clear impairment of neuronal metabolism already after 48 hours, represented by a significant reduction of the metabolic activity.
A Web Tool for Calculating Substituent Descriptors Compatible with Hammett Sigma Constants
Authors: Ertl Peter
Published: March 2021

Electron donating or accepting power of organic substituents is an important parameter affecting many properties of parent molecules, most notably their reactivity and pKa of ionizable groups. These substituent properties are usually described by Hammett sigma constants obtained by measuring ionization of substituted benzoic acids. Although values of these constants have been measured for the most common functional groups, data for many important substituents are not available. Some time ago we reported a method to calculate substituent descriptors compatible with Hammett sigma constants using quantum chemically derived parameters. The present publication revisits the older study by applying more sophisticated methodology and a larger training data set, as well as introduces a free web tool allowing to calculate substituent descriptors compatible with Hammett sigma constants available at https://bitly.com/getsigmas.
Molecular Mapping of Neutral Lipids using Silicon Nanopost Arrays and TIMS Imaging Mass Spectrometry
Authors: Fincher Jarod , Djambazova Katerina , Klein Dustin R. , Dufresne Martin , Migas Lukasz , Van de Plas Raf , Caprioli Richard , Spraggins Jeffrey
Published: March 2021

Our work demonstrates the ability to perform high spatial resolution imaging mass spectrometry (IMS) using silicon nanopost arrays (NAPA), a matrix-free laser desorption ionization (LDI) substrate, for multiple classes of neutral lipids from biological tissue sections.

Utilized trapped ion-mobility spectrometry (TIMS) coupled with IMS to enhance the molecular coverage of detected neutral lipid species, as well as for differentiating neutral lipid isomeric species spatial distributions.
Non-Innocent Electrophiles Unlock Exogenous Base-Free Coupling Reactions
Authors: Toupalas Georgios , Morandi Bill
Published: March 2021

Transition metal catalysis has revolutionized our ability to precisely manipulate matter and has placed itself at the forefront of the combat against societal challenges through key discoveries in drug design, agriculture, material synthesis and environmental sciences. Numerous important transition metal catalyzed reactions rely on stoichiometric quantities of an exogenous base to enable catalytic turnover. Despite playing a fundamental role, paradoxically, the base poses major challenges on several fronts, such as restricting the accessible chemical space due to functional group incompatibilities, or causing heterogeneous reaction mixtures that affect reproducibility, scale-up campaigns, and the implementation of emerging technologies, e.g. flow chemistry or high-throughput experimentation. Ultimately, this impedes innovation across multiple areas. Here we introduce a unifying strategy that eliminates the need for an exogenous base through the use of non-innocent electrophiles (NIE). Key to its success was the encryption of the base into the electrophile rendering it non-innocent, thus preserving the synthetic utility of the original reaction while overcoming the challenges associated with the exogenous base. The use of nickel as an earth-abundant metal catalyst as well as the employment of ubiquitous phenol derivatives as non-innocent electrophiles are further salient features of this sustainable protocol. The universal applicability of this concept was demonstrated by turning multiple traditionally base-dependent catalytic reactions, e.g. the Buchwald-Hartwig amination, the Mizoroki-Heck reaction and the Suzuki-Miyaura coupling, into exogenous base-free homogeneous processes. In a broader context, the results presented in this work provide a conceptual blueprint for the utilization of non-innocent electrophiles to overcome core limitations and unlock novel features in catalysis.
Uncovering Halide Mixing and Octahedral Dynamics in Vacancy-Ordered Double Perovskites by Multinuclear Magnetic Resonance Spectroscopy
Authors: Karmakar Abhoy , Mukhopadhyay Srija , Gachod Pierre , Gomez Arturo , Bernard Guy , Brown Alex , Michaelis Vladimir
Published: March 2021

Vacancy-ordered double perovskites Cs2SnX6 (X = Cl, Br, I) have emerged as promising lead-free and ambient-stable materials for photovoltaic and optoelectronic applications. To advance these promising materials, it is crucial to determine the correlations between physical properties and their local structure and dynamics. Solid-state NMR spectroscopy of multiple NMR-active nuclei (133Cs, 119Sn and 35Cl) in these cesium tin(IV) halides has been used to decode the structure, which plays a key role in the materials’ optical properties. The 119Sn NMR chemical shifts span approximately 4000 ppm and the 119Sn spin-lattice relaxation times span three orders of magnitude when the halogen goes from chlorine to iodine in these diamagnetic compounds. Moreover, ultrawideline 35Cl NMR spectroscopy for Cs2SnCl6 indicates an axially symmetric chlorine electric field gradient tensor with a large quadrupolar coupling constant of ca. 32 MHz, suggesting a chlorine that is directly attached to Sn(IV) ions. Variable temperature 119Sn spin lattice relaxation time measurements uncover the presence of hidden dynamics of octahedral SnI6 units in Cs2SnI6 with a low activation energy barrier of 12.45 kJ/mol (0.129 eV). We further show that complete mixed-halide solid solutions of Cs2SnClxBr6−x and Cs2SnBrxI6−x (0 ≤ x ≤ 6) form at any halogen compositional ratio. 119Sn and 133Cs NMR spectroscopy resolve the unique local SnClnBr6−nand SnBrnI6−n (n = 0−6) octahedral and CsBrmI12−m (m = 0−12) cuboctahedral environments in the mixed-halide samples. The experimentally observed 119Sn NMR results are consistent with magnetic shielding parameters obtained by density functional theory computations to verify random halogen distribution in mixed-halide analogues. Finally, we demonstrate the difference in the local structures and optical absorption properties of Cs2SnI6 samples prepared by solvent-assisted and solvent-free synthesis routes.
Oscillation in Excited State Lifetimes with Size of Sub-Nanometer Neutral (TiO2)n Clusters Observed with Ultrafast Pump-Probe Spectroscopy
Authors: Garcia Jacob , Heald Lauren , shaffer ryan , Sayres Scott
Published: March 2021

Neutral titanium oxide clusters of up to 1 nm in diameter (TiO2)n, with n < 10, are produced in a laser vaporization source and subsequently ionized by a sequence of femtosecond laser pulses. Using 400 nm pump, 800 nm probe lasers, the excited state lifetimes of neutral (TiO2)n clusters are measured. All clusters exhibit a rapid relaxation lifetime of ~30 fs, followed by a sub-picosecond lifetime that we attribute to carrier recombination. The excited state lifetimes oscillate with size, with even numbered clusters possessing longer lifetimes. Density functional theory calculations show the excited state lifetimes are correlated with electron-hole pair localization or polaron-like formation in the excited states of neutral clusters. Thus, structural rigidity is suggested as a feature for extending excited state lifetimes in titania materials.
PENGARUH PEMBERIAN MAKANAN TAMBAHAN (MT) TERHADAP PENINGKATAN BERAT BADAN, KADAR HEMOGLOBIN (Hb) DAN ALBUMIN PADA IBU HAMIL KURANG ENERGI KRONIS
Authors: Bakri Sri Handayani
Published: March 2021

Abstrak Pembangunan kesehatan dalam periode 2015-2019 difokuskan pada empat program prioritas yaitu penurunan angka kematian ibu dan bayi, penurunan prevalensi balita pendek Penelitian ini bertujuan untuk menilai besar perbedaan perubahan antara kelompok intervensi dan kelompok kontrol sebelum dan susudah pemberian makanan tambahan pada ibu hamil KEK. Jenis penelitian desain Quasi Eksperimental dengan rancangan pretest- postest control group design. Sampel dalam penelitian ini ibu hamil Kurang energi kronis (KEK) yang mengkonsumsi biskuit makanan tambahan dan tablet tambah darah (Fe) sebanyak 22 orang (kelompok intervensi) dan ibu hamil KEK yang hanya mengkonsumsi tamblet tambah darah (Fe) sebanyak 22 orang (kelompok kontrol) selama 3 bulan. Analisis data menggunakan uji Paired T Test dan uji independent test. Hasil penelitian menunjukan tidak ada perbedaan peningkatan berat badan dan kadar albumin antara kelompok intervensi dan kontrol sebelum dan sesudah pemberian biskuit makanan tambahan dan tablet Fe dengan p value=0,096 dan p=0,066. Ada perbedaan kadar hemoglobin antara kelompok intervensi dan kontrol sebelum dan sesudah pemberian biskuit makanan tambahan dan tablet Fe dengan nilai p= 0,021  Kata kunci: Biskuit makanan tambahan, ibu hamil kurang energy kronis peningkatan Berat badan, kadar hemoglobin dan albumin  AbstractHealth development in the period 2015-2019 is focused on four priority programs namely decreasing maternal and infant mortality, decreasing prevalence of short toddler. This study aims to investigate the changes between the two groups of chronic energy deficient pregnant mothers (intervention and control) before and after the introduction to suplememntary food. The research is set in quais-experimentation with pretest and posttest design of control group design. The samples are 22 pregnant mothers having chrionic energy deficient consuming supplementary food of biscuits and blood boosting tablet (Fe) (intervention) and other 22 pregnant mothers of similar condition were given blood boosting tablet only (control). The data were analyzed with Paired T Test and Independent test. The study indicates that no significant difference in weight gain and albumin level between the intervention and the control group before and after meal and the pill with the values=0.96 and=0.066 respctively. There is a significant difference in the hemoglobin level in the two groups before and after the supplementary food and Fe pills with a value of p=0.021  Keywords: Supplementary food biscuits, chronic energy deficient pregnant mothers, body weight, hemoglobin and albumin level
-بين السهل والجبل الحقيقة في تبيان ماهو سامي و غير سامي في كردستان القديمة- بحث في اللغة و الفن
Authors: M. Ahmed Kozad
Published: March 2021

يعتبر الكثير من الكتاب و الباحثين ان بعض المناطق و الاصقاع الواقعة الآن ضمن اراضي كردستان القديمة مواطن لسكن الجماعات السامية او على الاقل، انها كانت تحت التاثير السامي، و ذلك استنادا الى الاسماء الشخصية و الجغرافية و اسماء بعض الآلهة. كذلك يستشهد البعض بتاصيل بعض الاسماء الجغرافية للدلالة على ارتباط تلك الاصقاع باثنية معينة، و الحق ان الابحاث اللاحقة اظهرت خطأ الكثير من التفسيرات و التاصيلات اللغوية، كما هي الحال في اسم اربيل مثلا، و لكن الافكار الخاطئة رغم ذلك لا تزال شائعة و تتكرر في الكتاب تلو الكتاب و البحث تلو البحث. و لم تقتصر تلك الاخطاء على الجانب اللغوي، بل تعدتها الى الجوانب الفنية و الآثار، مما جعل الباحثين الاوائل يعزون ما يعرف بشجرة الحياة المقدسة مثلا الى الآشوريين ليعتبروها من صميم تراثهم. يهدف هذا البحث الى تصحيح البعض من هذه الافكار و اعادة الحقوق الى اصحابها ما امكن
Role of Mobile Technology in Vocabulary Development of Students with Hearing Impairment
Authors: Muntaha Ahmad  , Ghulam Fatima  , Misbah Malik
Published: March 2021

Purpose: The purpose of this quantitative research was to identify the role of mobile technology in the vocabulary development of students with hearing impairment.

Methodology: The population of study involved students with hearing impairment from schools in Lahore. A sample of 80 students studying at National Special Education Center, Johar Town Lahore, and Govt. Degree College of Special Education, Lahore was selected studying from 7th grade to bachelors. A self-developed and validated questionnaire was used to elicit students` responses on the usage of mobile technology in the aspect of reading, writing, social media and grammar and punctuation skills. Data was collected personally by going to the institutions and distributing the questionnaires among students. A sign language interpreter translated the questions in sign language and the students gave appropriate answers. The collected data was analysed on SPSS. Independent sample t-test was used to see differences in the vocabulary development based on the usage, age, gender, and grade of the students.

Findings: Major findings revealed that mobile technology is playing a significant role in learning vocabulary among students with hearing impairment. It has played a major role in learning new words and connecting with the world more quickly.

Implications: This technology should be used for academic purposes to improve their language skills and bridge the communication gap. Conclusions were drawn and recommendations to Punjab Special Education Department of Pakistan were made.
Efecto de la aplicación de bioreguladores para el control de Moniliophthora roreri y Phytophthora palmivora en cacao CCN-51 (Theobroma cacao)
Authors: Rodríguez-Lozano Rodrigo
Published: March 2021

El cacao ecuatoriano adquiere cada vez más importancia en los mercados internacionales. El desarrollo de técnicas sustentables es fundamental para productividad. El objetivo del presente estudio fue determinar el efecto de Bacthon y Tricho-D con dos periodos de aplicación para el control de Moniliophthora roreri y Phytophthora palmivora en cacao CCN-51. La investigación se desarrolló en la parroquia Pancho Negro, La Troncal, Cañar. Se analizaron tres métodos y dos periodos de aplicación más un testigo, con cuatro repeticiones. Se determino que el uso de Bacthon al suelo más Tricho-D a la planta ha superado en la mayor parte de las variables productivas, sanitarias y económicas del estudio. En cuanto a los periodos de aplicación evaluados, se obtuvo mejores resultados cuando las aplicaciones fueron realizadas con mayor frecuencia. Concluyendo que las aplicaciones con biorreguladores son más efectivas cuando se las realizan en menor lapso y directamente al suelo.
Sistemas de labranza y su incidencia sobre híbridos de maíz cultivado
Authors: Álvarez-Arias Juan , Caicedo-Camposano Oscar , Salas-Macías Carlos
Published: March 2021

El propósito de este estudio fue establecer el efecto de tres sistemas de labranza y su incidencia sobre las propiedades físicas del suelo, la germinación, desarrollo y rendimiento del maíz duro amarillo en el cantón Babahoyo. Se utilizaron tres tratamientos de labranza: i) Labranza Convencional (LC); ii) Labranza mínima (LM) y iii) Labranza cero (LC0) en donde se cultivaron tres híbridos de maíz. De los resultados obtenidos se concluye que los sistemas de labranza en términos aritméticos, produjeron cambios mínimos sobre las propiedades físicas del suelo (densidad aparente (Da), porosidad (P), resistencia mecánica (RM) e infiltración); observándose los cambios más consistentes prácticamente en la capa superficial con LC0, en estas mismas condiciones de labranza las raíces de los tres híbridos estudiados, alcanzaron un mayor volumen, altura de planta,  peso del 1000 granos y rendimiento. Con respecto a la relación grano/tusa no se registraron diferencias estadísticamente significativas.
Structure, thermophysical properties and electrical conductivity of nanocomposites based on epoxy polymer and carbon tubes
Authors: Korskanov V.V. , Fesenko O.M. , Dolgoshey V.B.
Published: March 2021

The aim of this work was to find the optimal conditions for the formation of nanocomposites, study their structure and properties and conditions for the formation of multicomponent materials based on epoxy polymers and carbon nanotubes with predetermined performance properties.
The basis for the formation of epoxy polymers was an epoxydian oligomer (EDO) based on bisphenol A. Polypox H354 was used as a hardener for EDO.
Carbon nanotubes (CNT) were used as a nanofiller for the preparation of nanocomposites.
The research methods were a diffractometer for measuring the intensity of X-ray scattering in the region of small angles and a differential scanning calorimeter for obtaining heating thermograms.
The electrical conductivity of the samples at a temperature of 293 K was measured at direct current according to the two-electrode scheme.
In this work the structure, thermophysical properties and electrical conductivity of nanocomposites based epoxy polymers and carbon  nanotubes have been studied. It was found that at low CNT content the formation of nanocomposites occurs by the mechanism of epoxy network growth, which is accompanied by the displacement of CNT particles to the periphery of the epoxy matrix. This process is accompanied by an increase in the scattering intensity of the SAXS, a rapid increase in the glass transition temperature and the degree of crosslinking of the epoxy polymer. When the critical concentration is reached, CNT particles form a continuous cluster, which leads to occurrence percolation threshold, reducing the glass transition temperature, expanding the glass transition range, occurrence of pores and reducing the degree of completion of the crosslinking reaction in nanocomposites relative to the epoxy polymer. It is established that the improvement of nanocomposite properties and the occurrence of the percolation threshold is due to the maximum specific energy of ER-CNT interaction and is achieved at a critical mass concentration of nanofiller from 0,1% to 0,4%.
Intensification of loosening of asbestos fibers by means of hydromechanical processing
Authors: Obodovich O.M. , Nedbailo O.M. , Chernyshyn O.G. , Nedbailo A.E.
Published: March 2021

Acceptance of high-quality aqueous suspensions based on chrysotile asbestos is an urgent technical task in a number of industries. Asbestos-cement mortar is used as an asbestos-cement crust for insulation of walls and other building surfaces, due to this composition of the treated surfaces perfectly retain heat, resistant to moisture, and most importantly - asbestos fibers contribute to the smoothness of the surface and crack is not formed. No less popular is the use of asbestos-cement mortar with a high content of asbestos in the insulation of ventilation ducts and pipelines. This composition of asbestos-cement mortar is used to strengthen the joints of asbestos-cement pipes, as well as as a filler in the laying of cast iron pipes to give the joints additional elasticity.
Asbestos-cement mortar has plasticity, resistance to stretching and reinforcement of asbestos, as well as strength and versatility in the use of cement. Due to these properties, asbestos and cement perfectly adhere to each other to obtain a durable, strong, frost-resistant, virtually waterproof and fire-resistant building material.
The result of the microscopic examination is reason to believe that from the technological process of production of slate can be removed electromechanical mixer for the preparation of a solution of asbestos + water + portland cement. In this case, given the fact of continued loosening of asbestos in the preparation of the mold mixture of asbestos + water + portland cement, it will be sufficient to ensure the degree of loosening of asbestos in the ripper at the minimum required level (for example, not more than 85%). It is assumed to obtain a mold mixture with a high degree of homogeneity of the components with reduced costs of Portland cement due to its physico-chemical activation by hydraulic fluxes.
Valor económico del agua en el Distrito de Riego 100, Alfajayucan, Hidalgo
Authors: Martínez-Luna Domingo , Mora-Flores José S. , Exebio-García Adolfo A. , Arana-Coronado Oscar A. , Arjona-Suárez Enrique
Published: March 2021

El agua para consumo humano se distribuye entre los f ines que la demandan: doméstico, agropecuario e industrial. De acuerdo a lo reportado por la FAO y UNESCO la agricultura consume 69%, el consumo doméstico utiliza 10% y la industria el 21%. Dada la importancia del agua en la agricultura se requiere conocer la asignación óptima del recurso dado un patrón de cultivos, así como el valor económico del líquido. El objetivo de este trabajo fue el obtener un patrón óptimo de cultivos en el Distrito de Riego (DR) 100 Alfajayucan Hidalgo, así como el de estimar el precio económico del agua ante distintos escenarios. La hipótesis establece que las tarifas pagadas por los agricultores en el DR 100 no reflejan su verdadero valor de escasez. Se instrumentó un modelo de programación lineal para maximizar el ingreso neto de los agricultores con 17 actividades agrícolas cíclicas y perenes, sujetas a 57 restricciones de superf icie, agua, mano de obra y maquinaria. Los resultados indican que el ingreso neto del DR 100 se incrementaría en 273 millones de pesos si se establece el patrón óptimo de cultivos, en comparación con el obtenido en el ciclo agrícola 2015-2016. El precio económico del agua arrojado por el modelo fue de $1.44 m-3, muy superior al pagado actualmente por las cuotas de riego ($0.02 m‑3), se conf irma la existencia de un fuerte subsidio al consumo de agua: por lo que se recomienda se incrementen las cuotas pagadas por los agricultores.
Diversidad de hongos micorrízicos arbusculares asociados a calabaza italiana (Cucurbita pepo L.) bajo acolchado plástico en campo.
Authors: Lara-Capistrán Liliana , Zulueta-Rodríguez Ramón , Reyes-Pérez Juan José , Murillo-Amador Bernardo , Ledea-Rodríguez José Leonardo , Hernández-Montiel Luis Guillermo
Published: March 2021

Las comunidades microbianas tienen efectos sobre el crecimiento y productividad de los cultivos. Sin embargo, se pueden ver afectadas por diversas prácticas agrícolas. El objetivo de la investigación fue determinar la diversidad de hongos micorrízicos arbusculares (HMA) asociados al cultivo de calabaza italiana establecido en campo bajo acolchado plástico. Se evaluó la colonización, riqueza, abundancia, e índice de diversidad micorrízica en ocho tratamientos: V (vermicomposta), APB (acolchado plástico blanco), APB+V; APR (acolchado plástico rojo), APR+V; APN (acolchado plástico negro), APN+V y C (control = sin vermicomposta y acolchado plástico), distribuidos en un diseño de bloques al azar de efectos aleatorios en arreglo factorial, y las interacciones vermicomposta (con y sin vermicomposta), acolchado (sin acolchar, con APR, APB, APN) y ciclo de cultivo invierno-primavera (I-P) y verano-otoño (V-O) con tres repeticiones. Para el análisis estadístico se utilizó el software Statistica v. 12.0 para Windows. Tras comprobar la distribución normal de los datos y la homogeneidad de las varianzas, se realizaron análisis de varianza multifactorial y las medias se compararon según el criterio de Tukey (α = 0.05). Para colonización micorrízica y riqueza el ANOVA mostró diferencias signif icativas (P ≤ 0.05) por efecto de la vermicomposta, el acolchado plástico y el ciclo de cultivo. En la abundancia relativa de HMA, el número de esporas de Acaulospora morrowiae fue el más alto en el tratamiento APN (37.0%) del ciclo I-P, y la misma predisposición natural ocurrió en el ciclo V-O, donde A. morrowiae fue la morfoespecie predominante (50%) en el tratamiento APN. En índice de diversidad solo influyeron los factores vermicomposta y acolchado plástico. Se identif icaron 21 morfoespecies en V-O y solo 12 en I-P, y se constató que el APN afectó a los HMA en todas las variables evaluadas.
Cómputo con palabras para evaluar la eficiencia organizacional con ANFIS
Authors: Montes Dorantes Pascual Noradino , Garza Ruiz Bertha Alicia , Maximiliano Méndez Gerardo
Published: March 2021

En este artículo se analizan las razones por las que no se pueden asignar en una organización valores numéricos de forma simple a sus componentes, yaque el uso de las variables lingüísticas estas, son difíciles de ser medidas con precisión por métodos tradicionales. Por ello, se expone un método novedosopara evaluar la eficiencia de una organización por medio de los modelos de cómputo suave, como lo son la Red Adaptativa Neuro-Difusa (ANFIS por sus siglas en inglés) y el cómputo con palabras que son capaces de realizarlo al transformar los datos lingüísticos en numéricos y viceversa. El campo de investigación incluye una revisión básica de la literatura y una postura reflexiva de los investigadores. El objetivo principal es desarrollar y probar un modelo para evaluar la eficiencia de la organización apoyada en técnicas de inteligencia artificial como la red adaptativa de inferencia difusa (ANFIS). La propuesta es relevante y pertinente dado que hoy en día aún no existe un consenso entre los diferentes expertos en los diferentes campos de la ciencia de lo que es la organización. Se concluye que es necesaria una definición ingenieril debido a que el concepto requiere de una aproximación matemática dada la falta de consenso, lo complejo del mismo, la no linealidad y la incertidumbre generada por eluso del lenguaje natural y a la falta de modelos de evaluación de eficiencia.
Stokiyometri Oranının İki Hücreli PEM Yakıt Hücresi Yığını Performansına Etkisinin İncelenmesi
Authors: CELLEK Muhammed , BİLGİLİ Muhittin
Published: March 2021

Buhar enerjisinin sanayide kullanılmaya başlanmasıyla beraber fosil yakıtların önemi artmıştır. Fakat özellikle son günlerde küresel ısınma sorunu dünyada ciddi olarak hissedilmektedir. Bu sorunun en önemli sebebi de fosil yakıtların yakılmasıyla açığa çıkan zararlı emisyonlardır. Dünya bu sorunu ortadan kaldırmak amacıyla çeşitli alternatif enerji kaynaklarına yönelmiştir. Son zamanlarda alternatif enerji dönüştürücüleri arasında yer alan PEM yakıt hücrelerine olan ilgi artmaktadır. Bu çalışmada, iki hücreli PEM yakıt hücresi yığını performansına stokiyometri oranının etkisi sayısal olarak incelenmiştir. Her biri 5,4 cm2 aktif alana sahip iki yakıt hücresi seri bağlanarak gaz akış kanalları paralel olacak şekilde belirlenip yığın haline getirilmiştir. Gerekli sayısal hesaplamalar yapılıp çeşitli potansiyel fark değerlerinde (1 V, 1,2 V, 1,4 V, 1,6 V, 1,8 V) beş farklı stokiyometri oranı (“1,5”, “2”, “2,5”, “3”, “3,5”) kullanılarak sayısal analizler gerçekleştirilmiştir. Beş farklı stokiyometri değeri için polarizasyon eğrileri ve güç-akım yoğunluğu eğrileri elde edilmiştir. Ayrıca sabit bir voltajdaki stokiyometri oranının etkisini görebilmek için en fazla güç miktarının elde edildiği 1Volt değerinde dört farklı stokiyometrik oran ile oluşan membran sıcaklık dağılımı, anot kütle kesri dağılımı ve katot kütle kesrinin dağılımları elde edilmiştir. Bu çalışma ile stokiyometrik oranın artmasıyla birlikte akım yoğunluğunun arttığı, bu artış oranının azalarak devam ettiği görülmüştür. En yüksek güç değerine ise 3,5 stokiyometrik oranında ve 1 V değerinde ulaşılmıştır. Bununla birlikte artan stokiyometrik oranla beraber membran sıcaklığında kısıtlı artış gerçekleşirken anot ve katot kanallarında hidrojen ve oksijen dağılımlarının daha homojen hale geldiği sonucuna ulaşılmıştır.
Conocimientos de los estomatólogos sobre bioseguridad en tiempos de COVID-19
Authors: González Espangler Liuba , Frómeta Ortiz Yonnelis , Valdés Gómez Yailén , Romero García Lázaro Ibrahim
Published: March 2021

Objetivo: describir el nivel de conocimientosde los estomatólogos sobre la bioseguridad ante la COVID-19 e identificar su relación con variables de interés.Las investigaciones sobre bioseguridad estomatológica en tiempos de COVID-19 han sido un tema recurrente en la actualidad y cobran una especial importancia,pues brindan pautas y permiten comparar el comportamiento de este fenómeno en diferentes centros.Materiales y métodos: es una investigación observacional descriptiva y transversal enlos servicios estomatológicos cubanos del municipio Mella de la provincia Santiago de Cuba, ennoviembre de 2020. La población estuvo constituida por estomatólogos, seleccionándose una muestra de 40.Se estudiaron variables como ocupación profesional, años de graduado y nivel de conocimientos sobre bioseguridad que se identificó como adecuado, medianamente adecuado e inadecuado según encuestas aplicadas. Resultados: en los tres primeros ítems evaluados predominó el nivel de conocimientos inadecuado (en el 50,0 % sobre medidas generales, en el 47,5 % acerca de la higiene de las manos y 40,0 % en la protección personal); en grado medio el manejo de prendas y cuidado del medio ambiente con un 50,0 y 75,0 % respectivamente; además, no existieron diferencias estadísticamente significativas entre el nivel de conocimientos y la ocupación profesional y los años de graduado.Conclusiones:el nivel de conocimientosde los estomatólogos sobre la bioseguridad ante la COVID-19 es medianamente adecuado y no depende ni del nivel de especialización ni de la experiencia profesional.
Contributing Factors for Turkey Consumption: An Empirical Analysis from Mymensingh City in Bangladesh
Authors: Yasmin Sarah , Sowrove Nur -E- Abir , Haque Tasnim , Hossain Mohammad Ismail
Published: March 2021

The study examined the factors influencing yearly consumption of turkey meat in Mymensingh city area. Data were collected from 60 consumers of turkey meat through Purposive sampling technique and face to face interview. Dummy coding was applied to code independent variables which were categorical in nature and multiple linear regression was carried out to find out the factors influencing consumption of turkey meat. Result indicated that the majority of the consumers (more than 50%) favored taste, color and aroma of turkey meat. The findings also revealed that age (P<0.05) and monthly family income (P<0.01) were significantly influencing yearly consumption of turkey meat among consumers in Mymensingh city. The major difficulty faced by the turkey farmer recognized as unavailability of turkey feed in the market, high price of day-old chick, lack of access to agricultural credit, lack of training and marketing facility and un-availability of vaccines. Analyzing the factors affecting consumption of turkey meat would facilitate in marketing decision making process of the turkey farmers and also deliver information to policy makers of Government as well as Department of Livestock Services to take necessary initiatives and support this alternative meat source to rise as a popular consumer choice.
OSMANLI SU MEDENİYETİNİN BİR TEMSİLCİSİ: ALDANZADE HACI OSMAN ÇEŞMESİ VE ONARIMI
Authors: ŞİMŞEK TOLACI Seda , KARAGÖZ Mehmet Ali
Published: March 2021

Çeşme yapıları Türklerin tarih boyunca meydana getirdikleri imar faaliyetlerinden bir tanesidir. Toplumun temel ihtiyaçlarından olan su gereksiniminin devlet ya da hayırseverler eliyle karşılanması farklı dönemlerde farklı tipte çeşme yapılarının inşa edilmesini sağlamıştır. Isparta il merkezinde 20. yüzyıla kadar çok sayıda çeşme yapısı bulunurken, bunlardan çok azı günümüze kadar ulaşabilmiştir. Kentte bulunan Aldanzade Hacı Osman Çeşmesi de bunlardan bir tanesidir. Osmanlı Döneminde İnşa edilmiş olan yapı, basit mahalle/sokak çeşmeleri tipolojisine dâhil edilebilecek kültürel miras değerlerimizdendir.

Çalışma kapsamını, çeşitli nedenlerde hasar gören bu yapının onarımının gerçekleşmesi için gerekli projelendirme aşamaları ve uygulama sonucu oluşturmaktadır. Uygulama öncesinde analitik rölöve çalışması, restitüsyon ve restorasyon projeleri, müdahale uygulama önerileri hazırlanmış, geliştirilmiştir. Verilerin toplanması ve değerlendirilebilmesi için gerekli olan literatür araştırmaları, ölçümleme ve krokilendirme dahil olmak üzere gerekli tüm alan çalışmaları gerçekleştirilmiştir.

Hazırlanan çalışmalar, projeler ve raporları müdahale yöntemleri ve fotoğraf albümü ile birlikte ilgili kurula (Antalya Kültür Varlıklarını Koruma Bölge Kurulu Müdürlüğü) sunulmuş, onaylanan proje sonrasında yapı, gerekli iznin alınması ile Isparta Belediyesi aracılığı ile hasarı oluşturan ilgili firma tarafından, proje dâhilinde, en az müdahale ile onarılmıştır. Böylece inşa edildiği dönemin izlerini taşıyan ve sahip olduğu bozulmalarında giderilmesi ile özgünlük değeri artan tescilli bir eser daha gerçek sahipleri olan mahalle kullanıcısına, tarihsel süreçte belleklerinde yer aldığı şekli ve özgün işleviyle yeniden sunulmuştur.
PEMANFAATAN LAMINASI BAMBU PETUNG UNTUK BAHAN BANGUNAN
Authors: Priyanto Agus , Yasin Iskandar
Published: March 2021

Bambu adalah salah satu tanaman yang cepat tumbuh. Jika untuk kayu dengan kelas awet yang tinggi membutuhkan waktu dari penanaman bibit hingga siap dipanen adalh 30 â€“ 40 tahun dan itupun setelah ditebang maka harus ditanam bibit lagi maka bambu cukup memakan waktu hingga 4 â€“ 5 tahun untuk siap dipanen dan tiap tahun bisa ditebang terus tanpa perlu menanam lagi. Dengan pemanfaatan teknologi laminasi maka bulah-bilah bambu dapat dimanfaatkan untuk dijadikan balok dengan berbagai ukuran dan berbagai bentuk. Laminasi dapat membuat kekuatan bambu Petung jauh lebih tinggi dibanding balok kayu solid.Pengujian dilakukan dengan uji fisik dan mekanik serta uji blok geser laminasi bambu Petung. Pada pengujian sifat fisik dan mekanik berdasarkan pada peraturan ISO 1975. Pengujian sifat fisik bambu Petung meliputi uji kerapatan kayu dan uji kadar air. Pengujian sifat mekanik bambu Petung meliputi uji kuat tekan sejajar serat, uji kuat tekan tegak lurus serat, uji kuat tarik, uji kuat geser dan uji kuat lentur. Pengujian blok geser laminasi bambu Petung untuk mengetahui kuat laminasinya mepunyai variasi perekat labur 30 MDGL, 40 MDGL dan 50 MDGL dengan masing-masing 3 ulangan pengujian geser.Kerapatan bambu Petung diperoleh rata-rata sebesar 0,63 t/m3 dan kadar air rata-rata bambu Petung sebesar 12,83 %. Kuat tekan sejajar serat rata-rata sebesar 26,85 MPa dan kuat tekan tegak lurus serat rata-rata sebesar 9,62 MPa. Kuat tarik bambu Petung rata-rata sebesar 226,39 MPa dan kuat geser rata-rata bambu Petung sebesar 7,88 MPa. Pada pengujian kuat lentur bambu Petung rata-rata sebesar 95,08 MPa. Pengujian blok geser laminasi bambu Petung untuk 30/MDGL diperoleh rata-rata sebesar 1,105 kg/mm2. Pada blok geser 40/MDGL diperoleh kuat geser rata-rata sebesar 1,133 kg/mm2. Untuk blok geser laminasi 50/MDGL diperoleh kuat geser rata-rata sebesar 1,427 kg/mm2.