bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peran Capping Agent terhadap Morfologi SrTiO3 Bulat Berongga yang Terbentuk dari Susunan Nanokubus melalui Metode Solvotermal
Authors: Putri Yulia Eka , Saputri Merida , Anwar Rahmadhini , Andriani Nova , Najeela Rathesa , Ilmi Thalabul , Wellia Diana Vanda 
Published: May 2019

SrTiO3 bulat berongga yang tersusun dari nano kubus telah disintesis dengan penambahan cetyltrimethylammonium bromide (CTAB) sebagai capping agent untuk mengontrol morfologi partikel. Kondisi sintesis pada suhu 220 °C selama 48 jam dengan perbandingan mol Sr:Ti = 1:1.25 dan perbandingan material awal dengan CTAB adalah 1:0.5 menghasilkan partikel dengan kristalinitas yang tinggi pada puncak spesifik 2θ = 32.41o bidang 110 yang merujuk pada struktur perovskit kubus. Penghalusan struktur kristal dengan metoda Rietveld menunjukkan bahwa struktur kristal hasil pengukuran memiliki kecocokan yang tinggi dengan hasil perhitungan dengan nilai Rwp adalah 12.07. Interaksi antara CTAB dan permukaan SrTiO3 terlacak pada spektrum FTIR dengan angka gelombang 1100-1250 cm-1 membuktikan adanya vibrasi ulur C-N yang melemah akibat proses capping. Foto SEM menunjukkan bahwa partikel yang terbentuk umumnya memiliki bentuk bulat berongga, sementara foto TEM memperlihatkan partikel berongga berukuran mikro dibentuk dari susunan nanokubus berukuran rata-rata 20 nm. Kata kunci: Capping agent, partikel berongga, nanokubus, solvotermal, perovskite The synthesis of SrTiO3 hollow sphere built as assembly of nanocubes using cetyltrimethylammonium bromide (CTAB) as capping agent was aimed to control the size and shape of the particles. The condition of the synthesis at 220 °C for 48 hours with a molar ratio of Sr:Ti was 1:1.25 and starting material:CTAB was 1:0.5, have resulted the particles with a high crystallinity with specific XRD peaks at 2θ; 32.41 (110), which was in agreement with the cube-perovskite structure. The refinement of the crystal structure by the Rietveld method showed that the crystal structure of the measurement results has a high match with the result of the calculation with Rwp value was 12.07. The interaction between CTAB and the surface of SrTiO3 traced in the FTIR spectrum with wave number 1100-1250 cm-1 indicated the stretching vibration of C-N was weakened due to the capping process. SEM images showed the particles with hollow microsphere, while TEM images revealed that the hollow particles were assembled by nanocubes with an average size of 20 nm. Keywords: Capping agent, hollow, nanocube, solvothermal, perovskite.
Sol-Gel Entrapment of Enzymes
Authors: Bergogné Laurie , Fennouh Souad , Guyon Stéphanie , Roux Cécile , Livage Jacques 
Published: May 2019

ABSTRACTTwo enzymes, lipase and β-galactosidase, have been encapsulated within
sol-gel matrices. Enzymatic activity of encapsulated lipase for hydrolysis
and trans-esterification reactions is maintained. Encapsulation yields
depend not only on the sol-gel porous texture but also on the water amount
added for the sol-gel synthesis and the hydratation history of the enzyme.
When the water amount is low, the highly active enzyme conformation
generated by the phase separation is frozen during gelation.
Escherichia Coli have been also encapsulated. The
cellular organization appears to be well preserved. Their β-galactosidase
activity seems to be better in wet gels but decreases dramatically upon
drying.
Macroporous Bulk Gels and Thin Films by Colloidal Templating of
Emulsions and Latex Particles
Authors: Subramanian G. , Manoharan V. N. , PINE D. J. 
Published: May 2019

ABSTRACTWe present a new way of making macroporous materials using colloidal
suspensions of ceramic nanoparticles. We start from a mondisperse emulsion
of 0.5 to 3.0 μm diameter oil droplets suspended in an aqueous colloidal
dispersion of 80–100 nm silica particles. Upon evaporation of the water, the
silica particles form a particulate gel around the emulsion droplets.
Removal of the emulsion droplets by dissolution in alcohol and subsequent
drying produces a monolithic solid macroporous body. Bulk gels with volume
greater than 1 cm3 could be easily produced with this method.
Uniform films with thickness of approximately 10 μm have also been made by
dip coating of the emulsion-silica colloid mixture. One can also use
polystyrene particles as templates in place of the emulsion droplets. Using
this approach, we were able to produce highly ordered macroporous titania
and silica ceramics with pore sizes around 500 nm and typical dimensions of
3.0 × 2.0 × 0.5 mm3. These dimensions are much larger than those
produced using alkoxides. Lower shrinkage associated with particulate gels
reduces cracking and increases the structural integrity of the macroporous
body.
Tailoring of organically-modified silica MCM-41 type materials
with dye molecules
Authors: Lebeau Bénédicte , Fowler Christabel E. , Mann Stephen 
Published: May 2019

ABSTRACTMicelle templated co-condensation of tetraethoxysilane and
3-(2,4-dinitrophenylamino)-propyltriethoxysilane was used to covalently
attach an organic chromophore into silica materials with MCM-41
architecture. Hexagonally highly-ordered mesoporous dye-functionalized
silica materials with various dye contents (up to 43 wt%) were precipitated
from alkaline and acidic aqueous solutions containing cetyltrimethylammonium
bromide (C16TMAB) surfactant. These materials were obtained in
the form of powders, excluding their use in thin film applications, such as
required for membrane and optical devices. Therefore, an evaporation-induced
self assembly process was used to prepare transparent mesostructured
dye-functionalized silica thin films and monoliths. Analogous materials with
increased pore channel sizes were fabricated by addition of the micelle
swelling agent 1,3,5-trimethylbenzene to the reaction mixture or by
replacing C16TMAB surfactant by an amphiphilic triblock copolymer
(poly (ethylene oxide)-block-poly (propylene
oxide)-block-poly (ethylene oxide)). This synthetic
route was also used to produce bimodal mesostructured dye-modified silica
materials using both latex spheres and C16TMAB micelles as
organic structure-directing agents.
Modification of Montmorillonite with PEO-b-PS
Copolymers
Authors: Beyer Frederick L. , Beck Tan Nora C. 
Published: May 2019

ABSTRACTWyoming montmorillonite has been modified with block copolymers of poly
(styrene) (PS) and poly(ethylene oxide) (PEO). Using melt intercalation
techniques, PEO-b-PS copolymers spanning a range of volume fractions and
molecular weights were mixed with montmorillonite, annealed above the
Tg of PS, and characterized using X-ray diffraction. Most of
the block copolymers intercalated the clay, with several samples exhibiting
multiple Bragg reflections from increased gallery spacing. Samples with
higher PEO volume fractions were most likely to have intercalation. For a
given PS block length, longer PEO blocks were more likely to produce
intercalation. In general, the increased gallery spacings were close to
those produced by modifying montmorillonite with PEO homopolymer.
Porous oxide thin layers using mesophase
templating
Authors: Klotz Michaela , Idrissi-Kandri Noureddine , Ayral André , Guizard Christian 
Published: May 2019

ABSTRACTHexagonal mesoporous silica layers were first prepared by the sol-gel route
from solutions containing silicon alkoxides as silica precursors and
alkyltrimethylammonium bromides to form the templating liquid crystal
mesophase. The synthesis conditions required to obtain well-ordered
crack-free layers were investigated. Two main synthesis parameters were
identified. The first one is the aging time of the sol before deposition
which defines the size of the inorganic cluster before the thin layer
deposition and the simultaneous phase formation. The second important
synthesis parameter is the surfactant volume fraction in the medium after
the departure of the volatile components. Well-ordered hexagonal layers were
obtained for surfactant volume fractions in agreement with the
water-surfactant binary diagram. These synthesis conditions were extended to
cubic and lamellar phases and to other types of surfactants, gemini
(cationic surfactants with two polar head groups) and non-ionic triblock
copolymers. First results concerning the extension of this approach to the
preparation of alumina thin layers are finally presented.
Porous Gel Coatings Obtained by Phase Separation in ORMOSIL
System
Authors: Nakanishi Kazuki , Kumon Souichi , Hirao Kazuyuki , Jinnai Hiroshi 
Published: May 2019

ABSTRACTMacroporous silicate thick films were prepared by a sol-gel dip-coating
method accompanied by the phase separation using methyl-trimethoxysilane
(MTMS), nitric acid and dimethylformamide (DMF) as starting components. The
morphology of the film varied to a large extent depending on the time
elapsed after the hydrolysis until the dipping of the coating solution. On a
glass substrate, the films prepared by early dipping had inhomogeneous
submicrometer-sized pores on the surface of the film. At increased reaction
times, relatively narrow sized isolated macropores were observed and their
size gradually decreased with the increase of reaction time. On a polyester
substrate, in contrast, micrometer-sized isolated spherical gel domains were
homogeneously deposited by earlier dippings. With an increase of reaction
time, the volume fraction of the gel phase increased, then the morphology of
the coating transformed into co-continuous gel domains and macropores, and
finally inverted into the continuous gel domains with isolated macropores.
The overall morphological variation with the reaction time was explained in
terms of the phase separation and the structure freezing by the forced
gelation, both of which were induced by the evaporation of methanol during
the dipping operation.
Electrical and Optical Interconnection-Technology based on
Ormocer - Inorganic-Organic Hybrid
Materials
Authors: Popall Michael , Buestrich Ralf , Kahlenberg Frank , Andersson Annika , Haglund Joacim , Robertsson Mats E. , Blau Gerd , Gale Mike , Rösch Oliver , Dabek Alexander , Neumann-Rodekirch Jens , Cergel Lubomir , Lambert Daniel 
Published: May 2019

ABSTRACTPhotopatternable hybrid inorganic-organic polymers with negative resist
behaviour have been developed and tested for evaluation in optical and
electrical interconnection technology. They are composed of inorganic oxidic
structures cross-linked or substituted by organic groups. The synthesis
starts from organosilane precursors reacted by sol-gel-processing in
combination with organic crosslinking of polymerisable organic functions. As
a result of these functionalities the properties of the ORMOCER®s are
adjusted to the particular applications. Systematic variation of composition
combined with adaptation to micro system technology allows great flexibility
in processing. The main features of these materials are:• Combined use as dielectric and passivation layers in electrical systems
and devices as well as core and cladding for optical applications enables
e/o applications with high integration levels.• Postbaking at moderate temperatures (120 - 170 °C) enables processing on
low-cost substrates such as FR-4 (a glass-fibre reinforced
epoxy-polymer).• Easily adaptable to thin film technology: spin-on with planarisation >
90 %, via diameters down to 20 μm and high aspect ratio for optical
waveguides have been achieved.Synthesis, modification of the resins towards technological needs, their
thin film technology and the resulting demonstrators will be discussed.
Effect of the stirring speed on the struvite formation using the centrate from a WWTP
Authors: Gonzalez Morales Carolina , Camargo-Valero Miller Alonso , Molina Pérez Francisco José , Fernández Belén 
Published: May 2019

The formation of struvite (MgNH4PO4·6H2O) for nutrient recovery in wastewater treatment plants has been widely investigated; however, little attention has been paid to the effect of stirring speeds on the resulting particle size, which could affect its agronomic value as a slow-release fertilizer. In this study, struvite formation from the centrate of sewage digestate was performed under six stirring speeds (0, 100, 200, 300, 400, 500 rpm). The resulting struvite crystals were characterised using X-ray diffraction and scanning electron microscopy with energy dispersive X-ray spectroscopy. The average particle size of struvite crystals increased from 55 µm at 0 rpm to 127 µm at 100 rpm and 128 μm at 200 rpm. Further increments in stirring speeds resulted in smaller crystal sizes. These results indicated that the largest particle size can be obtained at stirring speeds ranging from 100 to 200 rpm, equivalent to a velocity gradient between 79 and 188 s-1, as there was no statistically significant difference between mean values (t-test, p<0.05). The optimum stirring speed range reported herein can be used to set operational conditions for struvite crystallisation with the benefit of producing large crystals and reducing energy consumption in stirring tanks.
OR/MS research perspectives in disaster operations management: a literature review
Authors: Lamos Díaz Henry , Aguilar Imitola Karin , Acosta Amado Rolando José 
Published: May 2019

The unexpectedness of natural disasters makes handling their impacts on the population, the environment and the economic resources a challenging decision-making process that must be wisely performed in a very short period of time. The process involves the allocation of scarce resources to deliver aid and relief to the affected population in order to minimize the consequences of the event. An adequate management of operations to disaster response is challenging for decision makers and it has become a topic of significant relevance on a worldwide basis. As a result, academics and practitioners in the field of OR/MS have increased their interest in developing tools to support the decision-making processes on a disaster scenario. This paper surveys the OR/MS literature to identify new trends of increasing interest in disaster operations management (DOM) that have emerged in the last five years. A discussion on the gaps that have been successfully addressed in the last five years and those that remain opened is also presented.
Tympanoplasty with and without cortical mastoidectomy in treatment of inactive mucosal chronic otitis media
Authors: Aggarwal Divya , Vemu Sandeep , Kapur Sunil 
Published: May 2019

<p class="abstract"><strong>Background:</strong> Tympano-mastoidectomy has been found to be an effective method of treatment of chronic ear infection, but the effect of mastoidectomy on patients without evidence of active infectious disease in mastoid remains highly debated and unproven. Analyse the surgical outcomes of repair of uncomplicated tympanic membrane perforations with tympanoplasty alone and tympanoplasty combined with mastoidectomy.</p><p class="abstract"><strong>Methods:</strong> The present study was a prospective, comparative, randomized controlled trial in which 60 patients 30 in each groups via simple random sampling technique underwent tympanoplasty with cortical mastoidectomy. Temporalis fascia was used as graft in all the cases. All the surgeries were done by post aural route and underlay technique was used in all cases. </p><p class="abstract"><strong>Results:</strong> The overall graft uptake rate in our study was 88.33%. The graft uptake rate in tympanoplasty group was 87% and 90% in the tympanoplasty with cortical mastoidectomy group. There was no significant difference in the graft uptake rates of the two groups. There was no statistical significance between the two groups as p&gt;0.05, suggesting that mastoidectomy when combined with tympanoplasty offers no benefit over tympanoplasty alone. There was no significant difference in hearing gain between the two groups as p value obtained was &gt;0.05.</p><p class="abstract"><strong>Conclusions:</strong> Tympanoplasty alone is sufficient in patients with chronic inactive mucosal otitis media, as the results of the graft uptake and hearing improvement show no significant difference between the tympanoplasty group and the tympanoplasty with cortical mastoidectomy group.</p>
Impact of Home-to-Centre Distance on Bone Marrow Transplantation Outcomes
Authors: Al Naabi Malak , Al Khabori Murtadha , Al-Huneini Mohammed , Al-Rawas Abdulhakeem , Dennison David 
Published: May 2019

Objectives: Haematopoietic stem cell transplantation (HSCT) in Oman started in 1994 at Sultan Qaboos University Hospital (SQUH), Muscat, Oman. Previous studies have suggested that longer driving time to the transplant centre (DTC) independently correlates with worse overall survival (OS). Therefore, this study aimed to examine the impact of DTC on OS and acute graft-versus-host disease (aGvHD). Methods: This retrospective study included all patients who underwent HSCT between February 2006 and December 2016 at SQUH. The DTC was determined using Google Maps (Google LLC., Mountain View, California, USA). The probability of OS was estimated using a Kaplan-Meier estimator and the impact of DTC on OS was compared using a Cox model. Results: A total of 170 patients were included in this study of which 52% were male and 28% were from the Al Batinah region. The mean age was 14.2 ± 12.2 years. The mean haemoglobin, platelet and white blood cell counts before the HSCT were 10.3 ± 1.7 g/dL, 207 ± 131 × 109/L and 5.1 ± 5.9 × 109/L, respectively. The median DTC for those with aGvHD was 84 minutes, which is similar to patients without aGvHD (P = 0.918). The hazard ratio for DTC as a predictor of OS was 1.0 (P = 0.901). Conclusion: In this single centre study, DTC did not impact aGvHD or OS in patients post-HSCT. The study was limited by its retrospective design and the small sample size. It is recommended that these results be confirmed in a prospective study. Keywords: Hematopoietic Stem Cell Transplantation; Graft Versus Host Disease; Survival Analysis; Travel; Oman.
Medical Graduates’ Research Practices and Perceptions: A comparative cross-sectional study between 2015 and 2017 graduates of King Abdulaziz University
Authors: Basakran Ahmed M. , Banjari Maysaa A. , Almarghoub Malak A. , Alzarnougi Elaf M. 
Published: May 2019

Objectives: This study aimed to compare changes in medical students’ research practices and perceptions of two cohorts of graduates. Methods: This cross-sectional comparative study was conducted from November 2014 to December 2017 and included the 2015 and 2017 medical graduates of King Abdulaziz University, Jeddah, Saudi Arabia. A validated self-administrated questionnaire, which included questions about participants’ age and gender, research activities, and obstacles to and motivators for research involvement was used. Results: A total of 484 graduates were included in this study (response rate: 96.8%). A significant difference was found between the 2015 and 2017 graduates who had not started any research project (48.4% versus 35%; P <0.001) and a 20% increase in the 2017 graduates’ confidence in their abilities to start their own projects was observed (P <0.001). Significantly more 2017 graduates were engaged in various research roles, other than 'author', compared to 2015 graduates (71.3% versus 55.4%; P <0.001). Career progression was the main motivator for both the 2015 and 2017 medical graduates to participate in research (79.5%). Reported obstacles to research included a lack of dedicated time for research and methodology training and a shortage of research project opportunities. Conclusion: This study highlights positive changes in attitudes towards and perceptions of research among medical graduates.Keywords: Medical Students; Research; Professional Practice; Attitude; Perception; Medical Education; Saudi Arabia.
DETERMINING THE LEVEL OF STUDENTS’ RESEARCH SKILLS AND DESIGN THE MODEL OF INFLUENCING FACTORS ON RESEARCH SKILLS
Authors: Ilyashenko Lubov k. 
Published: May 2019

Purpose of Study: The main purpose of this research was to determine the level of research skills of students and design the model of the factors influencing it. This analytical-descriptive research was carried out in two stages. First, the level of skill and ability of students was obtained and then, based on interviews with them, factors affecting their skill level were obtained in the form of a pattern.
Methodology: To do this research, first, the student's ability to research was studied to determine the status quo. To this end, a researcher-made questionnaire was designed to assess students' ability to research in four areas of knowledge of the components of scientific research, knowledge of types of scientific research, the ability to produce a scientific research proposal and the ability to perform and report scientific research. According to their answerers, their ability to be classified into three levels of limited, acceptable and advanced categorization.
Results: The results showed that more than 50% of students with a low level of satisfaction are eligible for the practical implementation of research. Also, the pattern showed that students, school and teachers, and parents are effective at their level of ability to do research.
Implications/Applications: After the implementation of the questionnaires, the results were shared with the participants and interviewed about the reasons and factors affecting their level. After the interview, repetitive clauses were identified and with the help of Max software, the pattern was designed.