bluuebunny/crossref_metadata_2025 huggingface dataset:
Short-Term Outcomes Are Comparable between Robotic-Arm Assisted and Traditional Total Knee Arthroplasty
Authors: Grosso Matthew J. , Li William T. , Hozack William J. , Sherman Matthew , Parvizi Javad , Courtney P. Maxwell
Published: October 2020

Robotic-arm assisted total knee arthroplasty (rTKA) was developed to provide for increased accuracy of component placement compared with conventional manual TKA (mTKA). Whether or not rTKA is cost-effective in a bundled payment model has yet to be addressed. The purpose of this comparative study was to evaluate the short-term clinical outcomes of rTKA and mTKA. We retrospectively reviewed a series of 4,086 consecutive primary TKA performed by one of five surgeons across six different hospitals at our institution from January 2016 to December 2018. Outcomes for rTKA cases (n = 581) and mTKA cases (n = 3,505) were compared using unmatched multivariate analysis and a matched cohort. We analyzed 90-day outcomes, episode-of-care claims data, and short form (SF-12) outcome scores to 2 years postoperatively. In matched bivariate analysis, there was no difference in episode-of-care costs, postacute care costs, complications, 90-day readmission rates, emergency department/urgent care visits, reoperations, and mortality between rTKA and mTKA patients (p > 0.05). Matched patients undergoing rTKA did have a shorter hospital length of stay (1.46 vs. 1.80 days, p < 0.001) and decreased rates of discharge to rehabilitation facilities (5.5 vs. 14.8%, p < 0.001). SF-12 scores were clinically similar. Multivariate analysis demonstrated no differences in any 90-day outcome. We conclude that patients undergoing rTKA have comparable costs, 90-day outcomes, and clinically similar improvements in functional outcome scores compared with mTKA patients. Further study is needed to determine whether rTKA will result in improved implant survivorship and long-term functional outcomes (Level of evidence III).
Preoperative Condition of the Patellofemoral Joint Does Not Negatively Impact Surgical Outcomes of Lateral Unicompartmental Knee Arthroplasty in the Short Term
Authors: Fujita Masahiro , Hiranaka Takafumi , Kamenaga Tomoyuki , Tsubosaka Masanori , Nakano Naoki , Hayashi Shinya , Kuroda Ryosuke , Matsumoto Tomoyuki
Published: October 2020

The relationship between patellofemoral joint (PFJ) degeneration and clinical outcomes following lateral unicompartmental knee arthroplasty (UKA) has not been well described thus far. This study aimed to investigate the relationship between the preoperative PFJ condition and postoperative outcomes and the changes in lower-limb and PFJ alignment after lateral UKA. This was a retrospective study including 54 patients (mean age 72.9 years) who underwent lateral UKA for isolated lateral knee osteoarthritis at our institution between March 2013 and January 2019. The Oxford Knee Score (OKS), the Knee Society Score-Knee (KSSK), and Knee Society Score-Function (KSSF), the degree of degeneration, tilting angle and lateral shift of the PFJ, and the hip-knee-ankle angle (HKA) were evaluated pre- and postoperatively. The average follow-up period was 2.8 (range 1–6.1) years. There was a significant improvement in the OKS, KSSK, and KSSF after lateral UKA. Preoperative degeneration of the PFJ did not correlate with the recovery of clinical scores. The degeneration, tilting angle, and lateral shift of the PFJ did not significantly progress following lateral UKA. The HKA was improved after lateral UKA, and there was no correlation between the HKA change and PFJ condition. Postoperative severe valgus knee alignment was associated with a greater tilting angle. Preoperative degeneration of the PFJ did not have a negative impact on postoperative outcomes, and no short-term changes in the degeneration, tilting angle, and lateral shift of the PFJ were observed. Correction of knee-joint alignment did not have a negative impact on the condition of the PFJ.
Knee Arthrofibrosis following Tibial Plateau Fracture Treated with Arthroscopic Lysis of Adhesions with Manipulation
Authors: Middleton Austin H. , Perlewitz Madeline A. , Edelstein Adam I. , Vetter Carole S.
Published: October 2020

Posttraumatic arthrofibrosis is a common problem encountered in the orthopaedic setting for which there is no agreement on the optimal management strategy. The literature does not optimally describe the efficacy of arthroscopic lysis of adhesions for arthrofibrosis following tibial plateau fracture. The purpose of this study is to quantify the efficacy of arthroscopic lysis of adhesions with manipulation for the treatment of arthrofibrosis of the knee in patients who previously underwent surgical management of tibial plateau fracture. All patients who underwent arthroscopic lysis of adhesions from a single surgeon since 1999 were retrospectively reviewed. Clinical outcomes were evaluated by flexion, extension, and range of motion (ROM) preoperatively, intraoperatively, and postoperatively at intervals of 1, 4, 8, and 12 weeks, and any additional long-term follow-up. A total of 28 patients who had developed arthrofibrosis following surgical management of a tibial plateau fracture and failed nonsurgical management of knee stiffness were included in this study. There were significant improvements in total ROM following intervention at all time points compared with preoperative values (p < 0.001), with mean improvements of 59.3 degrees intraoperatively, 32.9 degrees (1 week), 37.1 degrees (4 weeks), 41.5 degrees (8 weeks), and 47.6 degrees (12 weeks). There were significant improvements in degrees of knee flexion following intervention at all time points compared with preoperative values (p < 0.001), with mean improvements of 50.8 degrees intraoperatively, 27.3 degrees (1 week), 36.0 degrees (4 weeks), 38.3 degrees (8 weeks), and 43.9 degrees (12 weeks). There were significant increases in degrees of knee extension intraoperatively (8.5 degrees) and at 1 week postoperatively (5.9 degrees) compared with preoperative values (p <0.01). At 12 weeks postoperatively, those who had previously undergone external fixation had significantly greater increases in ROM (p = 0.048). Arthroscopic lysis of adhesions for knee arthrofibrosis following surgical management of tibial plateau fracture significantly improves knee ROM.
What Are the Factors Affecting Total Sleep Time During Video Polysomnography in Infants?
Authors: Paul Grace R. , Hayes Don , Tumin Dmitry , Gulati Ish , Jadcherla Sudarshan , Splaingard Mark L.
Published: October 2020

Objective The aim of the study is to investigate factors affecting total sleep time (TST) during infant polysomnography (PSG) and assess if <4 hours of TST is sufficient for accurate interpretation.

Study Design Overall, 242 PSGs performed in 194 infants <6 months of chronological age between March 2013 and December 2015 were reviewed to identify factors that affect TST, including age of infant, location and timing of study, presence of medical complexity, and presence of nasal tubes. A continuum of apnea-hypopnea index (AHI) in relation to TST was reviewed. Data were examined in infants who had TST <4 hours and low AHI.

Results Greater TST (p < 0.001) was noted among infants during nocturnal PSGs, at older chronological and post-menstrual ages, and without medical complexity. The presence of nasogastric/impedance probes reduced TST (p = 0.002). Elevated AHIs were identified even in PSGs with TST <4 hours. Short TST may have affected interpretation and delayed initial management in one infant without any inadvertent complications.

Conclusion Clinical factors such as PMA and medical complexity, and potentially modifiable factors such as time of day and location of study appeared to affect TST during infant PSGs. TST < 4 hours can be sufficient to identify high AHI allowing physician interpretation.

Key Points
Role of plasma parameters on the characteristics properties of flexible transparent ITO films deposited by 3D facing and planar facing magnetron sources
Authors: Sahu Bibhuti B. , Lee Min W. , Long Wen , Han Jeon G.
Published: October 2020

A rectangular closed and hollow three-dimensionally confined large area magnetron source (3-DCLAMS) and a conventional moderate area facing target magnetron source (FTMS) have been used to study the plasma characteristics using different diagnostics at different working pressures. Flexible indium tin oxide (ITO) films deposited at similar operating conditions using these sources were characterized by numerous standard analyses to study their film properties. The 3-DCLAMS with high discharge current at a low-discharge voltage is capable of generating high plasma density, which assists a high ion flux and energy density on the substrate that is necessary for the high growth rate deposition of highly conductive crystalline ITO films with smooth surface morphology. Utilizing suitable plasma characteristics, highly conductive and transparent ITO films of 30 nm with the minimum resistivity ρ ∼ 4.1 × 10−4 Ω cm and ∼9.3 × 10−4 Ω cm and average transmittance T ∼ 84% and 82%, respectively, were deposited in the 3-DCLAMS and the FTMS system. The presented result shows that the 3-DCLAMS system could be useful for making high-quality, flexible ITO films at a very high deposition rate of ∼250 nm/min.
Nonlocal rung-3.5 correlation from the density matrix expansion: Flat-plane condition, thermochemistry, and kinetics
Authors: Ramos Chloe , Janesko Benjamin G.
Published: October 2020

The rung-3.5 approach to density functional theory constructs nonlocal approximate correlation from the expectation values of nonlocal one-electron operators. This offers an inexpensive solution to hybrid functionals’ imbalance between exact nonlocal exchange and local approximate correlation. Our rung-3.5 correlation functionals also include a local complement to the nonlocal ingredient, analogous to the local exchange component of a hybrid functional. Here, we use the density matrix expansion (DME) to build rung-3.5 complements. We demonstrate how these provide a measure of local fractional occupancy and use them to approximate the flat-plane condition. We also use these complements in a three-parameter nonlocal correlation functional compatible with full nonlocal exchange. This functional approaches the accuracy of widely used hybrids for molecular thermochemistry and kinetics. The DME provides a foundation for practical, minimally empirical, nonlocal correlation functionals compatible with full nonlocal local exchange.
Balancing the ideals of public participation
Authors: Sjögren Maria
Published: October 2020

Local authorities in western societies increasingly initiate public participation processes despite criticism of these methods. To understand this development calls for in-depth studies of how the goals and values of public participation are articulated in practice. This paper analyzes the discursive legitimation strategies deployed by civil servants in twelve planning meetings for a participatory process aimed at mitigating violence in a Swedish suburb. The study draws on previous research on discursive legitimation, and presents the context-specific strategies of authorization, de-legitimation, cosmology and addressing of values. The analysis highlights that a core discursive tension in this practice arises from its need to seek mandate in the municipal structure, while the value discourses used to legitimize public participation build on a break from traditional bureaucracy. The study contributes to the broader literature on discursive legitimation in contemporary political contexts, with detailed empirical accounts of how a disputed practice is legitimized in interaction.
Epistemic modals in academic English
Authors: Carrió-Pastor María Luisa
Published: October 2020

The hypothesis of this paper is that writers who belong to
different specific fields of knowledge use dissimilar epistemic modals in academic
English. The first specific objective is to identify and contrast the epistemic
modals used in engineering, medicine and linguistics research papers and the second
is to classify the phraseological patterns associated with epistemic modals in these
specific settings. The method was based on a corpus-based approach and, for this
purpose, fifty academic papers in English belonging to the field of engineering,
fifty more from the domain of linguistics and another fifty from medical academic
journals were compiled. The results showed that there were differences in the
epistemic modals used and in the phraseological units composed in engineering,
medicine and linguistics research papers. Finally, conclusions were drawn.
Liquid–liquid phase separation driven compartmentalization of reactive nucleoplasm
Authors: Laghmach Rabia , Potoyan Davit A
Published: October 2020

The nucleus of eukaryotic cells harbors active and out of equilibrium environments conducive to diverse gene regulatory processes. On a molecular scale, gene regulatory processes take place within hierarchically compartmentalized sub-nuclear bodies. While the impact of nuclear structure on gene regulation is widely appreciated, it has remained much less clear whether and how gene regulation is impacting nuclear order itself. Recently, the liquid–liquid phase separation emerged as a fundamental mechanism driving the formation of biomolecular condensates, including membrane-less organelles, chromatin territories, and transcriptional domains. The transience and environmental sensitivity of biomolecular condensation are strongly suggestive of kinetic gene-regulatory control of phase separation. To better understand kinetic aspects controlling biomolecular phase-separation, we have constructed a minimalist model of the reactive nucleoplasm. The model is based on the Cahn–Hilliard formulation of ternary protein–RNA–nucleoplasm components coupled to non-equilibrium and spatially dependent gene expression. We find a broad range of kinetic regimes through an extensive set of simulations where the interplay of phase separation and reactive timescales can generate heterogeneous multi-modal gene expression patterns. Furthermore, the significance of this finding is that heterogeneity of gene expression is linked directly with the heterogeneity of length-scales in phase-separated condensates.
Resolving Hubble tension with quintom dark energy model *
Authors: Panpanich Sirachak , Burikham Piyabut , Ponglertsakul Supakchai , Tannukij Lunchakorn
Published: October 2020

Recent low-redshift observations have yielded the present-time Hubble parameter value

. This value is approximately 10% higher than the predicted value of

, based on Planck's observations of the Cosmic Microwave Background radiation (CMB) and the

CDM model. Phenomenologically, we show that, by adding an extra component, X, with negative density to the Friedmann equation, it can address the Hubble tension without changing the Planck's constraint on the matter and dark energy densities. To achieve a sufficiently small extra negative density, its equation-of-state parameter must satisfy

. We propose a quintom model of two scalar fields that realizes this condition and potentially alleviate the Hubble tension. One scalar field acts as a quintessence, while another “phantom” scalar conformally couples to matter such that a viable cosmological scenario is achieved. The model only depends on two parameters,

and

, which represent the rolling tendency of the self-interacting potential of the quintessence and the strength of the conformal phantom-matter coupling, respectively. The toy quintom model with

(Quintom I) yields a good Supernovae-Ia luminosity fit and acceptable

fit but slightly small acoustic multipole

. A full parameter scan revealed that the quintom model was superior to the

CDM model in certain regions of the parameter space,

, while significantly alleviating the Hubble tension, although it is not completely resolved. A benchmark quintom model, Quintom II, is presented as an example.
One-pot synthesis of spirooxindole-pyrrolizidine compounds using magnetically separable Fe3O4-graphene oxide (Fe3O4-GO) catalyst
Authors: Hapsari M , Cahyana A H , Yunarti R T
Published: October 2020

A couple of novel Spirooxindole-pyrrolizidine compounds have been synthesized from chalcone derivatives as α, β-unsaturated carbonyl compounds by the help of heterogeneous magnetically separable Fe3O4-GO catalyst. Four steps involved in this research are synthesis of Fe3O4-GO catalyst, synthesis of chalcone derivatives from 4-hydroxybenzaldehyde and cinnamaldehyde, synthesis of spirooxindole-pyrrolizidine derivatives by 1,3-dipolar-cycloaddition reaction through the formation of azomethine ylide, and the last is antioxidant activity assay using DPPH method. The result showed that the use of Fe3O4-GO catalyst as much as 5 wt% can increase the reaction yield to 86.27 %. From the DPPH assay, it is known that spirooxindole-pyrrolizidine derivatives have an antioxidant activity but spirooxindole-pyrrolizidine derived from 4-hydroxybenzaldehyde is the better one.
Phase system of hexane-water for SnO2 nanoparticles preparation using Cassia alata leaf extract and its photocatalytic activity
Authors: Hakim F L , Yulizar Y , Apriandanu D O B
Published: October 2020

SnO2 nanoparticles (NPs) were prepared using a hexane phase of Cassia alata leaf extract (CLE) and a water phase of SnCl2 precursor by high-speed stirring (HSS) method. In this study, HSS was utilized to analyze the nanoparticle formation via phase system of hexane-water. Next, the synthesized SnO2 NPs were characterized by Fourier transform infrared (FT-IR) spectroscopy, particle size analyzer (PSA), transmission electron microscopy (TEM), scanning electron microscopy energy-dispersive X-ray spectroscopy (SEM-EDX), UV-Vis diffuse reflectance spectroscopy (DRS) and X-ray diffraction (XRD). Phytochemical screening confirms that CLE contains secondary metabolites such as alkaloids as a source of base, saponins and tannin as a capping agent in SnO2 NPs formation. TEM characterization shows that the particle size of SnO2 NPs was approximately 25–50 nm. The photocatalytic activity of SnO2 NPs was tested for methylene blue (MB) degradation under UV light irradiation. As a result, the degradation percentage of MB was 70.29 % for 160 min.
Sixth-generation of ziegler-natta catalyst for homopolymer polypropylene polymerization: Effect to product properties and regulation
Authors: Syahrudin R I , Herlambang B A
Published: October 2020

The development of catalysts for polypropylene (PP) polymerization has begun since Ziegler-Natta (Z-N) discovered the catalyst for polyethylene polymerization. However, the first-generation catalyst which was a combination of TiCl3-AlEt2Cl (catalyst-co-catalyst) has low productivity and isotacticity. The modifications continue to be made to increase the productivity and isotacticity by combining the Z-N catalyst with MgCl2, internal donors, and external donors. The fourth-generation Z-N catalyst, TiCl4/Phthalate/MgCl2-AlEt3/Silane, has given satisfactory results with high productivity and isotacticity. Another concern arose when phthalate derivatives turned out to be able to initiate cancer formation. This problem has led catalyst development to the sixth-generation Z-N catalyst with a phthalate-free internal donor. This research intends to study the effects of sixth-generation catalysts to polypropylene properties when compared to the fourth-generation catalysts. We produced homopolymer polypropylene (HPP) by fourth- and sixth-generation of Z-N catalyst with the same polymerization technology. Then, the effects on product properties, namely melt flow rate (MFR), xylene soluble, residual catalyst, physical properties, optical properties, and rheological properties were observed. Sixth-generation catalyst exhibited a better stereoregularity and it made a better flexural modulus. The rheological properties showed the sixth-generation catalyst products have lower molecular weight and it generates fewer gels and lower impact strength. Sixth-generation catalyst also exhibited lower catalyst residue which allows lower dosage of an acid scavenger with comparable color performance. With increasingly strict restrictions on the use of phthalates, the sixth-generation catalyst is more convenient to use. In terms of the effect on the polypropylene properties, fourth-and sixth-generation catalysts have their respective advantages.
Effect of film fabricating conditions and its implications on mechanical properties of high-density polyethylene film
Authors: Herlambang B , Anando M R O B
Published: October 2020

The use of plastics, especially High-Density Polyethylene (HDPE) film has increased rapidly in recent years due to its low cost, lightweight and excellent mechanical properties which is depended on the extrusion condition in the owner’s film fabrication machine. The blown film process is the common process used to make a thermoplastic film in large volumes. However, many research performed long ago in the mechanical properties of polyethylene only concerned on the effect of conventional processing parameters such as temperature and pressure in blown film machines and neglected the significant effect of critical extrusion conditions. We did the study to know the effect of critical extrusion conditions such as output rate, blow-up ratio (BUR) and neck-point height (NPH) which was intended to get the optimum film fabrication conditions in a blown film extrusion machine. Each parameter was performed in five different conditions by increasing one parameter and controlling the other. The resin first melted, conveyed, and delivered before finally blown to form the film. The mechanical properties observed were impact resistance, tensile strength, elongation, tear strength, and young modulus. The result indicates that increasing the output rate, BUR and NPH imparted in the film’s orientation balance, bubble shape, relaxation, and crystallization effects will lead to the increase of impact resistance, decrease of tear strength, and balance of film direction properties. The excessive and low amount of output rate, BUR and NPH are not desirable as it decreases the mechanical properties from HDPE film whether in mechanical direction or transverse direction. Hence, the optimum operating condition depends on which mechanical properties that needed to be achieved by film fabricators.
Synthesis and characterization of zinc-aluminum and zinc-chromium LDHs intercalated citrate anion
Authors: Hidayati N , Azmi M F , Oktriyanti M , Palapa N R , Mohadi R , Elfita  , Lesbani A
Published: October 2020

In this study, the preparation of Zinc-Al and Zinc-Cr LDH intercalated by citrate anion conducted using co-precipitation method at room temperature. The characterization of Zinc-Al and Zinc-Cr LDHs intercalated citrate anion was performed using XRD and FTIR. The result of XRD pattern and FTIR spectra confirmed that Zinc-Al and Zinc-Cr intercalated citrate anion were successfully prepared. The vibration of citrate anion observed at 1590 cm−1 and 1390 cm−1, respectively, correspond to the characteristic of the carboxylate group (-COO-). Structure of Zinc-Al and Zinc-Cr LDHs were shown by reflection at 2 theta (003) that indicated the interlayer space was higher than before intercalation.
Simple isolation method of cannabinol from Cannabis sativa to produce secondary reference standard analysis material
Authors: Hidayati N , Saefumillah A , Cahyana A H
Published: October 2020

The simple isolation method of Cannabinol compounds from cannabis plants by maceration combined with ultrasonication assisted extraction, fractionation, separation and purification was carried out to obtain Cannabinol isolates which can be used as a reference standard analysis material. Ultrasonication was proven to shorten the extraction time, where extraction for 5 h with ultrasonication assisted for 15 min produced 5.536 % yield greater than the 24 h extraction. The results of extraction were fractionated using n-hexane and then chromatographically isolated with a column containing Silica Gel 60, with 2.5 cm diameter and a 15.3 cm height, eluted by n-hexane-ethyl acetate (90:10) solution. The fraction containing Cannabinol was purified using HPTLC preparative with eluent n-hexane-ethyl acetate (80:20). The purification of the Cannabinol isolate was further characterized by Spectrophotometer UV, FTIR, DCS, GCMS and LCMSMS and compared its profile to the reference standard of Cannabinol from Lipomed. The characterization results showed that the purified isolates had UV spectra with λ max at 219.0 nm and 284.5 nm, FTIR spectra at wave numbers 1620.21 cm−1, 1051.20 cm−1, 1581.63 cm−1, 1026.13 cm−1, 1128.36 cm−1 and 1232.51 cm−1. The DSC thermogram shows the melting point of compound is 74.36 °C with 99.35 % purity, GCMS fragmentation at m/z 295, 296, 238 and 310, LCMSMS with [M + H]+ at 311.1 and MS2 at 222.95, 292.95 and 240.95 confirmed the chemical structure of the compound. The results of the characterization of pure isolates indicate that the compound produced was Cannabinol in accordance with the standard characterization profile of the reference standard of Cannabinol used.
Phytochemical and antiacne investigation of Indonesian White Turmeric (Curcuma zedoaria) Rhizomes
Authors: Setyani D A , Rahayu D U C , Handayani S , Sugita P
Published: October 2020

White turmeric (Curcuma zedoaria) is one of plant species belongs to Zingiberaceae from Himalaya, India. Previous research showed that the rhizomes of this plant contained several secondary metabolites such as alkaloid, phenolic, and terpenoid which commonly known to have antibacterial activities. This study aims to investigate the phytochemical of white turmeric rhizomes growth in Indonesia and evaluate its antibacterial activity against Propionibacterium acnes and Staphylococcus epidermidis as acne-causing bacteria. In this study, secondary metabolites from Indonesian white turmeric rhizomes were successfully extracted in methanol and partitioned in polarity increasement of several organic solvents. Furthermore, crude and all partitioned extracts were subjected to phytochemical investigation. The ability of crude and ethyl acetate extracts to inhibit the growth of P. acnes and S. epidermidis were evaluated using disk diffusion method. According to the antibacterial activity results, all of samples did not exhibit antibacterial activity against both acne-causing bacteria. The results of this study will provide a useful information regarding the phytochemical and antiacne investigation of Indonesian white turmeric rhizomes.
Activity of hydrogenated curcuminoid on Pd/C catalyst and its antibacterial activity against Staphylococcus aureus and Streptococcus mutans
Authors: Adriani N H , Rahayu D U C , Saepudin E
Published: October 2020

Turmeric (Curcuma longa) has been known for its benefit as one of medicinal herbs. Curcuminoids, the active compounds in turmeric, consist of three structurally related compounds, curcumin, demethoxycurcumin, and bisdemethoxycurcumin. Curcuminoid has been reported to be effective for the treatment of chronic gingivitis and hence it can be a potential candidate to be used as an active ingredient for antimicrobial in a mouthwash. However, its yellow color has hampered its application as a mouthwash as it may cause the aesthetical problem to the teeth. In this study, curcuminoids, obtained from Soxhlet extraction of turmeric powder, were reduced by hydrogenation on Pd/C catalyst to remove the color. TLC analysis revealed that the products consist of three compounds as expected. The product was purified from unreacted curcuminoids by column chromatography on silica gel, to obtain a colorless product with percent conversion of 23.45 %. These three compounds were characterized by Uv-Vis spectrophotometer resulted in three peaks in three different wavelengths: 282, 283 and 280 nm. Characterization with FT-IR spectrometer showed an increase intensity of CH-sp3 peak (2932 cm−1) when compared to the IR spectrum of standard curcuminoids, and the shift in C-O absorption (1231 cm−1), indicated the existence of methoxy groups that can distinguish one to the other compounds. These three compounds then were evaluated for their antibacterial activity against Staphylococcus aureus and Streptococcus mutans. The result showed that the tetrahydrocurcumin had moderate antibacterial activity against S. aureus with inhibition zone of 5.5 mm and tetrahydro desmethoxycurcumin also showed moderate antibacterial activity against S. mutans with inhibition zone of 5.5 mm.
Characterization and Dielectric Properties of Fly Ash / Polystyrene / Low Density Polyethylene Composites
Authors: Nasr G M , Mohamed T A , Ahmed R M
Published: October 2020

Polystyrene (PS) and its blend with low density polyethylene (LDPE) were prepared by melting method. Fly ash was used as filler with different contents to form composites by the same way with PS/LDPE 80/20 blend. The obtained data of fly ash from X-Ray Fluorescence analysis displayed that the total mass summation of silicon, magnetite and aluminum (SiO2 + Fe2O3+ A12O3) is about 79.52 wt. % whereas the amount of calcium oxide is less than 10%. TGA curves showed that the sample of the more thermal stability was the composite that contains the highest amount of fly ash (50 wt.%). For all the samples, the dielectric constant and the dielectric loss were increasing by decreasing the applied frequencies while they were decreasing by increasing the temperatures. Also, increasing the fly ash content in the blend improved the ac conductivity up to a content of 40 wt.% then it decreased. The values of the real part of the electrical modulus (M’) did not equal to zero at low frequencies and high temperature. Therefore, it is expected that the electrode polarization may take place for the all samples.
Fano Resonance Properties in (K3C6o / HgBa2Ca2Cu3O10) 1D photonic crystal
Authors: Aly Arafa H , Mohamed D. , Abd El-Gawaad N. S. , Matar Z. S. , Trabeisi Y. , Mohaseb M. A.
Published: October 2020

The Fano resonance and Electromagnetic induced reflectance (EIR) properties in one-dimensional superconductor photonic crystals (SPCs) have been investigated theoretically by Transfer Matrix Method (TMM). The periodic structure consists of alternating of pair superconductor materials are made of (K3C60/HgBa2Ca2Cu3O10) one-dimensional photonic crystal. The SPCs is enclosed by dielectric cap layer at different induced fields. To exam the efficiency of the reported structure, different parameters are used for analysis such as layers thicknesses, temperature, angle of incidence and the dielectric constant, dielectric cap layer on the EIR and Fano line shape. The investigation results exhibits tunable Fano resonances and EIR resonance peaks accompanied by asymmetrical line shape very sensitive to dielectric cap layer, constituent materials and dependence incidence angle. This will be useful reference for different applications of photonic topological states in the integrated photonic devices and information processing chips.
The Effect of burnable absorbers on neutronic parameters of VVER-1200 reactor
Authors: Hafez Noura , Shahbunder Hesham , Amin Esmat , El-Kamessy S. U. , Elfiki S. A. , Latef Ahmed
Published: October 2020

The presence of burnable absorbers play an important role in the safety of nuclear reactors. So, seeking their influences on the reactor core behaviour is a crucial issue in both reactor core design and operation. Therefore, the aim of the present work is to study the effect of the gadolinium oxide burnable absorbers on one of the significant safety parameters of WER-1200/V392M core which is the neutron flux distribution. A full-scale three-dimensional model of the WER-1200/V392M core was performed using MCNP5/MCNPX transport code with ENDF/B-VII.O nuclear data library. The calculations were performed in the normal operation state for the first fuel cycle. Besides the neutron flux in both radial and axial distributions, the comparison between the fuel assemblies contained gadolinium oxide and that without gadolinium oxide is also discussed. Also, the effect of gadolinium oxide on the produced major actinides is investigated.
Tunable filter based on the 1D photonic crystal within ultraviolet radiations
Authors: Aly A. H. , Barakat S. , Amin A. F.
Published: October 2020

In the present study, we develop a one-dimensional semiconductor photonic crystal to control ultraviolet radiation. We study the transmittance spectra of incident light on the proposed structure in the ultraviolet regime. A photonic bandgap appears with a width of 95.2 nm. by changing the thickness parameters, it can reach up to 125.6 nm with appearing of new band gaps. The incident angle effect on the band gap’s width is apparent. The bandgap shifted to a lower wavelength region. So the proposed structure could be useful in preventing UV radiation from passing through it.
Effect of UV-activated TiO2 Nanoparticles on the Properties and Performance of PAni-TiO2 Nanocomposite Films for Solar Cell Applications
Authors: El-Hossary F. M. , Ghitas A. , Abd El-Rahman A. M. , Ebnalwaled A. A. , Abdelhamid Shahat M. , Fawey M. H.
Published: October 2020

To improve the performance of organic solar cells by enhancing the properties of the photoactivated nanocomposite layer, the UV irradiation process was used to activate titanium dioxide nanoparticles (TiO2 NPs). Herein, polymer solar cells were fabricated with FTO/(PAni-TiO2)/Ag system. A series of mixed polyaniline (PAni) with 20% of activated TiO2 NPs at different processing times was used to form PAni-TiO2 nanocomposite films. The structural evolution, surface characteristics, optical and electrical properties of PAni-TiO2 films have been investigated. XRD patterns showed that the UV treatment of TiO2 NPs increased the crystallite from 18.35 to 24.1 nm and the degree of crystallinity increased by 5.6%. The irradiated PAni-TiO2 films showed a rougher and more porous surface compared to the untreated one. Moreover, the adhesion force and electrical conductivity of the treated nanocomposite films at 8 h improved to be 137 mN/m and 6.62 S/m, respectively. Incorporation of activated TiO2 NPs exposure to UV for different times from 0 to 8 h with the PAni matrix enhanced the current density (Jsc) of PAni-TiO2 based nanocomposite solar cells from 3.11 to 4.83 (mA/cm2) and their efficiency from 0.33 to 0.85%. The increase in the solar cell efficiency is mostly ascribed to a structural change accompanied by a rapid increase in surface roughness, which led to a decrease in the reflected photons and thus an increase in the charge carriers produced. These results revealed the effect of surface UV irradiation of TiO2 NPs on their structural properties and the electronic contact between PAni and TiO2 NPs, which greatly influenced the amount of carrier transport within the PAni-TiO2 composites.
Pastoral
Authors: Little Katherine
Published: October 2020

Pastoral refers to any representation of the countryside or life in the countryside that emphasizes its beautiful and pleasurable aspects. Although the term has come to be used broadly to describe paintings, novels, and popular media, it originated and developed in the poetry of ancient Greece and Rome. Poems about shepherds and cowherds, also called bucolic, first appeared in the Idylls of Theocritus (3rd century bce), and these inspired the Roman poet Virgil to write a set of poems called the Eclogues (c. 42–37 bce). Virgil’s ten poems have been immensely influential. Indeed, pastoral’s long and relatively unbroken European history can be traced to the ongoing popularity of the Eclogues. These poems helped establish the defining elements of the mode: shepherds, who spend much of their time in song and dialogue; the topics of love, loss, and singing itself; a leisurely life; and a natural landscape of endless summer. In the Middle Ages, when Virgil’s eclogues were still read but rarely directly imitated, an explicitly Christian version of pastoral developed; this version was based in the shepherds of the Bible, both the literal shepherds who witnessed Jesus’ birth and the figurative shepherds referred to by Jesus or mentioned in the Psalms. In this biblical or ecclesiastical pastoral, authors used shepherds to discuss priestly duties and the state of the church more generally. Pastoral flourished in the Renaissance, when poets brought together Virgilian and Christian traditions, along with topical concerns about court politics and rural controversies, such as enclosure, to invent a new kind of poetry. During and after the Romantic period, pastoral lost its distinctly shepherdly focus and merged with a broader category of nature writing. As one of several possible approaches to nature, pastoral was reduced to its idealizing and nostalgic qualities, and it was often contrasted with more realistic or scientific representations. From the perspective of the longue durée, pastoral is a capacious category that includes many different attitudes toward rural people and rural life, even the realism of labor and exile. Despite this variety, pastoral is recognizable for the feelings it hopes to generate in its readers about rural life: the delight that the senses take in nature, the sadness at the loss of people and places, and the intense crushes of adolescence.
Virtual Identities
Authors: Dinnen Zara
Published: October 2020

Virtual identities stand in for a user or player in a virtual environment; they are social media profiles; digital subjects—of human and nonhuman agency. Virtual identities are often imagined as something distinct from the “self” of the user of digital media but technically and existentially they determine the ways a user navigates life online. Virtual identities, then, might also be a category that captures the ways identity itself is virtual; a force of existence that determines how subjects can orient themselves in the world. The questions of what virtual identities are, how they operate, and the kinds of material expression of personhood they afford and signify has been taken up in scholarship across the last thirty years from a variety of disciplines including computer sciences, critical race studies, game studies, gender and sexuality studies, literary studies, new media studies, social sciences, science and technology studies, and visual culture studies. As an imminent figure in early 21st-century life, virtual identities might describe subjects who exist in global digital media networks but who do not necessarily profit from their participation and labor, or who are not always visible. Despite the virtuality of virtual identities, their partial and fragmentary status, they exist as a technology by which to fix identity to an embodied subject—via facial recognition, or biometric scanning, or the coaxing and collection of personal data. The study of virtual identities remains an ongoing and significant task.
A Disproportionate Policy Perspective on the Politics of Crisis Management
Authors: Maor Moshe
Published: October 2020

Disproportionate policy response—which is composed of two core concepts, namely policy overreaction and under-reaction—is typically understood to be a lack of “fit” or balance between the costs of a public policy and the benefits deriving from this policy and/or between a policy’s ends and means. The disproportionate policy perspective introduces an intentional component into disproportionate response. It represents a conceptual turn whereby the concepts of policy overreaction and under-reaction are reentering the policy lexicon as types of intentional policy responses that are largely undertaken when political executives are vulnerable to voters. In times of crisis, disproportionate policy responses may be intentionally designed, implemented as planned, and sometimes successful in achieving policy goals and in delivering the political benefits sought by the political executives who design them. The premise underlying this argument is that crises vary in many respects, some of which may incentivize a deliberate crisis response by political executives that is either excessive, or lacking. For example, when crises occur at times of electoral vulnerability, the relevancy of policy instruments’ visibility, theatricality, spectacularity, and popularity may dominate the calculus of crisis management decisions. The same applies in cases where strong negative emotions emerge, and subsequently, political executives may opt to overwhelm hysterical populations cognitively and emotionally, trying to convince them that the policy system is viable.
Frontline Workers in Crisis Management
Authors: Kalkman Jori Pascal
Published: October 2020

Crises are uncertain and disorderly situations, which temporarily destabilize power relations and impede centralized control over operational crisis responders (e.g., firefighters, police officers, paramedics). Consequently, responders wield considerable autonomy and have room to act on their own initiative. They make crucial decisions in frontline crisis operations based on their situational understanding and professional expertise. As such, they are similar to other “frontline workers” (or street-level bureaucrats) in government service. Their important work has attracted increasing attention in crisis management literature, in which three tensions have emerged.

The first tension revolves around the nature and extent of frontline discretion. In some studies, these frontline responders are presented as implementers who are considerably constrained by extensive rules, planned routines, and detailed protocols. Other studies, instead, emphasize the independent and proactive behaviors of frontline workers who use their discretionary space to shape crisis response efforts. The second tension centers on the reasons for discretionary actions. Typically, crisis scholars analyze social and rule-based pressures on frontline workers to explain their discretionary actions as they implement public policy. Critics, instead, build on responders’ own stories to grasp their meaning-making attempts and use this as a basis for understanding why and how responders enact their discretionary practices. The final tension concerns the advantages and disadvantages of frontline worker discretion. There is a widespread belief that frontline discretion in crisis response enables much-needed improvisation, creativity, and flexibility, but increased discretion may also raise legitimacy questions and potentially burden frontline workers with complex ethical dilemmas.

To move the understanding of frontline workers in crisis management forward, further research is required in several areas. Empirically, frontline workers are increasingly working in transboundary crisis networks, so that more research is necessary to understand how such crisis networks affect frontline discretion. Theoretically, literature on frontline work in crisis management has remained by and large isolated from other micro-level theories on crisis management, even though there are opportunities for fruitful cross-fertilization with adjacent literatures.
SARS: A Crisis Analysis Case Study
Authors: Xue Lan , Zhong Kaibin
Published: October 2020

The severe acute respiratory syndrome (SARS) crisis was the first epidemic caused by a novel virus in the 21st century, killing nearly 774 globally and 349 in China. Started in late 2002, it escalated from a localized outbreak into a national and ultimately an international crisis within just a few months, before the outbreak was finally brought under control in June 2003. The governmental actors were caught off guard before a timely and comprehensive response was put in place in mid-April 2003.

As pandemics are becoming both more frequent and more devastating, it is important that efforts be made to intervene early in an outbreak to prevent a potential national and even global threat. The provincial and national governments did not take prompt and comprehensive actions, even after the disease began spreading quickly and taking lives. The Chinese government dramatically revamped their approach to SARS and took very decisive action to respond to the spread of the SARS virus in April 2003; this occurred only when decision makers had been informed of this crisis situation and put on notice to put crisis management on their radar screen and make it a “top priority.” Therefore, it’s necessary to understand what factors influenced the initial delayed response by local and national Chinese governments, from the perspective of information management and governmental political agenda.
Managing Critical Infrastructures in Crisis
Authors: Comfort Louise K.
Published: October 2020

The management of critical infrastructures presents a specific set of challenges to crisis managers. Critical infrastructures include electrical power; communications; transportation; and water, wastewater, and gas line distribution systems. Designed for efficiency, these technical systems operate interdependently, thus making them vulnerable to the stress of extreme events.

Changes in population, demographics, land use, and economic and social conditions of communities exposed to hazards have resulted in a significantly increased number of people dependent on critical infrastructures in regions at risk. Advances in science, technology, and engineering have introduced new possibilities for the redesign, maintenance, and retrofit of built infrastructure to withstand extreme events. However, most public and private agencies are not capable of anticipating the potential risk and making investments needed to upgrade infrastructures before damage occurs.

Computational modeling facilitates the exploration of alternative approaches to managing risk. Sensors, telemetry, and graphic display of changing performance for critical infrastructure provide accurate information to reduce uncertainty in crisis events. These technologies enable crisis managers to track more accurately the impact of extreme events on the populations and infrastructures of communities at risk and to anticipate the likely consequences of future hazardous events.

Crisis managers strive to create a continual learning process that enables residents to monitor their changing environment, use systematically collected data as the basis for analysis and change, and modify policies and practice based on valid evidence from actual environments at risk.

For communities seeking to reduce risk, investment in information technologies to enable rapid, community-wide access to interactive communication constitutes a major step toward building capacity not only for managing risk to critical infrastructure but also in maintaining continuity of operations for the whole community in extreme events.
Bahrain: The Army and the Dynamics of State-Society Relations
Authors: Louër Laurence
Published: October 2020

In contrast with some of its Gulf neighbors, Bahrain cannot develop a more socially embedded military institution that would be the engine of an inclusive nation-building process. This is because of the peculiar nature of its state–society relations, which are plagued by mutual distrust between the ruling Al Khalifa family, who hail from the country’s Sunni minority, and a great part of the Shia majoritarian population. As a result, the security apparatus, and the army in particular, recruits almost exclusively from the ruling family, its Sunni tribal allies, and foreigners. Totally insulated from the Shia society, the militaries never participated, nor will ever participate, in mass politics, which have been mostly driven by Shia-dominated protests. The noncompromise option taken by the incumbents following the mass protest of 2011 has entailed a shift toward a hard form of authoritarianism in which the security apparatus has emerged as a key actor of political control. The regime is increasingly militarized as the Al Khalifa militaries have acquired a growing weight in the politics of dynastic factionalism, with the militaries now being in crucial positions to influence not only the kingdom’s policies but also the internal balances within the ruling dynasty.