bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on lubrication state of cylinder liner‐piston ring based on resistance measurement method
Authors: Liu De‐Liang , Chen Wen‐Bin , Yan Zhi‐Jun , Zhang Shi‐Feng
Published: August 2020

Real‐time measurement of the lubrication state is one of the critical problems in studying the lubrication state and its transformation characteristics. Based on the experimental results, shrinkage resistance principle and Greenwood's contact theory, a mathematical model for cylinder liner‐piston ring that can be used to measure the resistance of film thickness ratio is established. On this foundation, the correspondence between the film thickness ratio and the contact resistance for cylinder liner‐piston ring was presented and the technical possibility to characterise the real‐time lubrication state was provided. An experimental study for determining the lubrication state of cylinder liner‐piston ring based on resistance measurement method was conducted on a reciprocating friction and wear tester to verify the applicability of resistance measurement method in cylinder liner‐piston ring friction pair. Results show that the contact resistance method is reliable and practicable to determine the lubrication state of cylinder liner‐piston ring friction pair.
Rheological Properties of Coordinated Physical Gelation and Chemical Crosslinking in Gelatin Methacryloyl (GelMA) Hydrogels
Authors: Young Ashlyn T. , White Olivia C. , Daniele Michael A.
Published: August 2020

Synthetically modified proteins, such as gelatin methacryloyl (GelMA), are growing in popularity for bioprinting and biofabrication. GelMA is a photocurable macromer that can rapidly form hydrogels, while also presenting bioactive peptide sequences for cellular adhesion and proliferation. The mechanical properties of GelMA are highly tunable by modifying the degree of substitution via synthesis conditions, though the effects of source material and thermal gelation have not been comprehensively characterized for lower concentration gels. Herein, the effects of animal source and processing sequence are investigated on scaffold mechanical properties. Hydrogels of 4–6 wt% are characterized. Depending on the temperature at crosslinking, the storage moduli for GelMA derived from pigs, cows, and cold‐water fish range from 723 to 7340 Pa, 516 to 3484 Pa, and 294 to 464 Pa, respectively. The maximum storage moduli are achieved only by coordinated physical gelation and chemical crosslinking. In this method, the classic thermo‐reversible gelation of gelatin occurs when GelMA is cooled below a thermal transition temperature, which is subsequently “locked in” by chemical crosslinking via photocuring. The effects of coordinated physical gelation and chemical crosslinking are demonstrated by precise photopatterning of cell‐laden microstructures, inducing different cellular behavior depending on the selected mechanical properties of GelMA.
Highly Swellable and Stretchable Thermoresponsive Hydrogels Enabled by Functionalized Boron Nitride Nanosheets
Authors: Guo Meiling , Du Jin , Zhang Junyao , Wu Yuanpeng , Xue Shishan , Yang Xi , Li Zhenyu , Zhou Hongwei , Lei Weiwei
Published: August 2020

Thermoresponsive hydrogels with high stretchability and large swelling ratio are promising materials for fabricating soft devices, sensors, artificial muscles, etc. However, it remains a challenge to achieve these properties simultaneously within one hydrogel. Herein, highly swellable and stretchable thermoresponsive hydrogels are developed by incorporating functionalized boron nitride nanosheets (f‐BNNSs) into poly(maleic anhydride functionalized β‐cyclodextrin‐co‐N‐isopropylacrylamide) hydrogel. In such hydrogels, the dynamic host–guest interactions between f‐BNNSs and polymer matrix act as sacrificial bonds to efficiently dissipate energy, and the homogeneous covalent cross‐linking network of polymer leads to a smooth stress propagation, which enables the hydrogels to obtain excellent mechanical properties, such as remarkable strength (up to 0.15 MPa) and outstanding stretchability (up to 1457%). What is more, the resultant hydrogel also exhibits excellent thermoresponsive properties (swelling rate up to 5000% at 25 °C and deswelling rate down to 6% at 50 °C). Thus, this work offers a promising strategy to fabricate highly swellable and stretchable thermoresponsive hydrogels for potential soft actuators and bionic robotics applications.
Solvent Polarity and Environment Sensitive Behavior of Coumarin Derivative
Authors: Koppal Varsha V. , Hebsur Rekha K. , Melavanki Raveendra. M. , Kusanure Raviraj , Patil N. R.
Published: August 2020

This paper reports an investigation on ground and excited state preferential solvation index (i.e., δs2) and relative quantum yield of 2‐acetyl‐3H‐benzo[f]chromen‐3‐one (2AHBC) molecule. The title molecule shows negative values of preferential solvation index in the ground state in different binary solvent mixtures, this confirms that molecule under study is preferentially solvated by 1,4‐dioxane (DXN) rather than acetonitrile (ACN). The excited state preferential solvation index is found to be positive which signifies strong predomination of solute–solvent interaction. Synergistic effect is confirmed by the higher values of fluorescence wave maximum in DXN and ACN solvents for 2AHBC. Further, quantum yield of 2AHBC molecule is estimated in solvents of different polarities. It is found that, non‐radiative decay constant is more than the radiative decay constant in all the solvents. This is attributed due to intermolecular forces between hydrogen atoms. Relative quantum yield of 2AHBC is found to be inversely proportional to the polarity of the solvents. This is due to the intermolecular charge transfer and bathochromic effect. Whereas, the influence of viscosity of the solvents on quantum yield of 2AHBC is studied and it is confirmed by the Forster–Hoffmann equation.
Green Synthesis of Silver Nanoparticles from Pterocarpus santalinus Leaf Broth and Their Antibacterial and Antioxidant Activities
Authors: V Vaishnavi , Sadasivuni Kishor Kumar , Ponnamma Deepalekshmi , Golla Narasimha
Published: August 2020

In this study, metallic silver nanoparticles (AgNPs) are synthesized through a simplistic, single‐step method, which is a green and eco‐friendly process, as it includes medicinal plant aqueous leaf extracts of Pterocarpus santalinus L. The formation of AgNPs in the filtrate is evaluated by its brown color and the peak appearance at 420 nm in the UV spectrophotometer. Peak formation in FTIR spectrum is an indication of the presence of functional groups and their role in the formation of nanoparticles from the aqueous leaf extract. Zeta potential studies are performed for determining the surface potential of AgNPs. The nanoparticles size (5–15 nm) and shape (spherical) are confirmed by transmission electron microscope. The AgNPs show good bactericidal and antioxidant activity against both gram‐positive and gram‐negative bacteria. The results suggest that the AgNPs can be used as antimicrobial agents in current nanomedicine, and also to improve the antibacterial performance of their polymer composites.
AIE Emission of SDS Capped Diphenylanthracene Nanoparticles for Selective Recognition and Estimation of Al3+ Ion in Aqueous Medium Based on Enhancement Effect and Analytical Application
Authors: Suryawanshi Sonali B. , Deshmukh Gunvant R. , Bodake Anita J. , Patil Shivajirao R.
Published: August 2020

The sodium dodecyl sulfate capped 9,10 Diphenylanthracene nanoparticles is prepared by using reprecipitation method. The average particle size of NPs obtained from DLS examination is 67 nm. The aqueous suspension of NPs exhibits red shifted aggregation induces enhanced emission. The zeta potential value—42.9 mV indicates stability of NPs and generation of expected negative surface charge over the NPs to attract and adsorb cations from the solution on the surface. The cation recognition test based on fluorescence shows that the presence of Al3+ ion significantly enhances the fluorescence of NPs. Furthermore, the proposed system is successfully applied for the detection of Al3+ ion from environmental water samples and Digene table available in the market. The advantage of developed analytical method is lower value of LOD and even in presence of interfering ion Mg2+ the Al3+ is estimated with no need of their separation prior to analysis.
Estimation of the Surface Free Energy of Hydrophobic Monolithic Silica Aerogels
Authors: Kavale Mahendra S. , Karande Subhash S. , Pushpanjali Gurubasappa M.
Published: August 2020

Aerogels are prepared by quantifying the sol–gel process of the organo‐metallic precursors. The objective of the present article is to synthesize ultralow density, low index of refraction, and monolithic silica aerogels. The quantification of hydrophobicity of the silica aerogels using water drop contact angle is not only crucial but also the estimation of the surface free energy is an important parameter to understand the interfacial behavior of the aerogel surface and liquid. To provide insight on this behavior, calculation of the surface free energy is done by using Neumann's equation of state. These synthesized aerogels emerged with ultralow density 24 kg m−3 and low thermal conductivity ∼0.091 W m−1 K−1.
Nanostructured CuO Thin Films Prepared by Aqueous Based Novel Reflux Method
Authors: Desai Pooja A. , Admuthe Aishwarya A. , Chougule Prajkta D. , Patil Shrutika G. , Dhole Indrajeet A. , Tonape Mallikarjun M.
Published: August 2020

Copper oxide (CuO) thin films have been deposited on glass and steel substrates but here work is done on steel substrate by novel aqueous based Reflux method whereas deposition of CuO thin film uses copper sulfate as copper ion source from an aqueous alkaline medium. The effects of copper ion concentration, temperature, and deposition time are studied for deposition of thin films. The CuO thin films are characterized by XRD, UV, SEM, and contact angle. The X‐Ray diffraction results reveal that CuO is monoclinic in nature. Optical band gap is observed from UV–visible spectrophotometer which is 1.9 eV. The surface morphological studies obtained from SEM micrograph show rice shape of exterior. While wettability test shows hydrophobic nature of CuO. This material characterization of CuO thin film clearly indicates that these films can be widely used in various applications such as gas sensor, transducers such as thermocouple to measure thermo e.m.f, solar cells, and super capacitor.
Prenatal diagnosis of Prader‐Willi syndrome due to uniparental disomy with NIPS: Case report and literature review
Authors: Shubina Jekaterina , Barkov Ilya Y. , Stupko Olga K. , Kuznetsova Maria V. , Goltsov Andrey Y. , Kochetkova Taisya O. , Trofimov Dmitry Y. , Sukhikh Gennady T.
Published: August 2020

Background

PWS is challenging to diagnose prenatally due to a lack of precise and well‐characterized fetal phenotypes and noninvasive markers. Here we present the case of prenatal diagnosis of Prader‐Willi syndrome, which was suspected with whole‐genome NIPS.

Methods

Whole‐genome noninvasive prenatal screening showed a high risk for trisomy 15. Amniocentesis followed by FISH analysis and SNP‐based chromosomal microarray was performed.

Results

Simultaneous analysis of maternal and fetal samples with SNP microarrays demonstrated maternal uniparental disomy (UPD).

Conclusion

The presented case is the first case of PWS described in detail, which was suspected by NIPS results. It demonstrates that the choice of confirmation methods concerning the time needed is crucial for the right diagnosis. We suppose that prenatal testing of UPD is essential for chromosome regions, which play a key role in the appearance of various gene‐imprinting failure syndromes like PWS or AS.
Drug Re‐positioning Studies for Novel HIV‐1 Inhibitors Using Binary QSAR Models and Multi‐target‐drivenIn SilicoStudies
Authors: Dogan Berna , Durdagi Serdar
Published: August 2020

Current antiretroviral therapies against HIV involve the usage of at least two drugs that target different stages of HIV life cycle. However, potential drug interactions and side effects pose a problem. A promising concept for complex disease treatment is ‘one molecule‐multiple target’ approach to overcome undesired effects of multiple drugs. Additionally, it is beneficial to consider drug re‐purposing due to the cost of taking a drug into the market. Taking these into account, here potential anti‐HIV compounds are suggested by virtually screening small approved drug molecules and clinical candidates. Initially, binary QSAR models are used to predict the therapeutic activity of around 7900 compounds against HIV and to predict the toxicity of molecules with high therapeutic activities. Selected compounds are considered for molecular docking studies against two targets, HIV‐1 protease enzyme, and chemokine co‐receptor CCR5. The top docking poses for all 549 molecules are then subjected to short (1 ns) individual molecular dynamics (MD) simulations and they are ranked based on their calculated relative binding free energies. Finally, 25 molecules are selected for long (200 ns) MD simulations, and 5 molecules are suggested as promising multi‐target HIV agents. The results of this study may open new avenues for the designing of new dual HIV‐1 inhibitor scaffolds.
Twisted cubic theta hypergeometric series
Authors: Chu Wenchang
Published: August 2020

The modified Abel lemma on summation by parts is employed to examine the “twisted” cubic theta hypergeometric series through three appropriately devised difference pairs. Several remarkable summation and transformation formulae are established. The associated reversal series are also evaluated in closed forms, that extend significantly the corresponding q‐series identities.
Existence and exponential decay for a nonlinear wave equation with nonlocal boundary conditions of 2N‐point type
Authors: Anh Triet Nguyen , Thi Phuong Ngoc Le , Pham Ngoc Dinh Alain , Thanh Long Nguyen
Published: August 2020

This paper is devoted to the study of a nonlinear wave equation with initial conditions and nonlocal boundary conditions of 2N‐point type, which connect the values of an unknown function u(x,t)  at x = 1, x = 0,  x = ηi(t), and x = θi(t), where
 
  for all t ≥ 0.  First, we prove local existence of a unique weak solution by using density arguments and applying the Banach's contraction principle. Next, under the suitable conditions, we show that the problem considered has a unique global solution u(t)  with energy decaying exponentially as t → +∞. Finally, we present numerical results.
Properties and numerical solution of an integral equation system to minimize airplane drag for a multiwing system
Authors: Junghanns Peter , Monegato Giovanni , Demasi Luciano
Published: August 2020

We consider an open multiwing system, composed of N ≥ 2 disjoint open plane curves, not necessarily symmetric, and examine the corresponding (constrained) induced drag minimization problem. To this end, we first derive the associated Euler‐Lagrange system of equations, which is then reduced to an equivalent system of Cauchy singular integral equations. By generalizing a previous approach of ours for the case of a single open wing, we obtain existence and uniqueness results for the problem solution in a product of weighted Sobolev type spaces. This system is then solved by applying to it a collocation‐quadrature method. For this, we prove stability and derive corresponding error estimates. Finally, to test the efficiency of the proposed numerical method, we apply it to some multiwing systems.
The characteristic matrix function of a dissipative Hamiltonian operator
Authors: Uğurlu Ekin
Published: August 2020

In this paper, we consider a singular dissipative even‐order Hamiltonian operator with a finite number of transmission conditions. Using coordinate‐free approach, we construct the characteristic matrix‐function of the Cayley transform of the dissipative operator. Using the equivalence of completeness property of root functions of Cayley transform and dissipative operator, we prove some completeness theorems. Moreover, we construct an explicit form of the resolvent operator of dissipative operator.
Existence of spiky steady state of chemotaxis models with logarithm sensitivity
Authors: Xu Xin
Published: August 2020

Chemotaxis is an important biological mechanism in the nature. We prove the existence of spiky steady states of the one‐dimensional continuous chemotaxis model with logarithm sensitivity in a more general case by using global bifurcation theory with chemotactic coefficient being the bifurcating parameter and by studying the asymptotic behavior of the steady states as the chemotactic coefficient goes to infinity. One can use spiky steady states to model the cell aggregation, which is one of the most important phenomenon in chemotaxis.
A calculation model of infrared detection system with improved detection capability
Authors: Lu Liping , Li Hanshan
Published: August 2020

In order to constantly and accurately recognize and track flying targets, using the infrared photoelectric detection system, while scientifically analyze the detection capability of the system, in complex background environments. This paper analyzes the measurement principle of the infrared photoelectric detection system, establishes a radiation energy calculation model of the background and the optical system and the target on the photoelectric detector surface. It further analyzes the influence of the photoelectric detector wavelength, the slit diaphragm and of the target effective radiation area, on the radiation energy. It obtains the contrast ratio calculation model between the target and the background, on the photoelectric detector surface, while it also derives the detection distance model of the system, combining the modulation transfer function of the system, to set up an improved detection distance calculation model, in complex background environments. Simulation and experimental analysis show that as background radiation brightness increases, in certain background environments, the detection distance of the system gradually reduces, while changing the slit diaphragm and photoelectric detector wavelength can improve the detection performance of the system. In complex background environments, changing the contrast ratio of photoelectric detector surface should be considered, to improve the detection capability of the system.
Two miniaturized triple‐band filters based on 900 sector substrate integrated waveguide
Authors: Zhang Sheng , Guo Ya , Zhou Yu‐Yu , Hong Jia‐Sheng
Published: August 2020

Two kinds of triple‐band filters based on 900 sector substrate integrated waveguide (SSIW) are firstly investigated. The resonant frequencies of SSIW are deduced by analogy with a circular SIW cavity. By contrast, SSIW cavity is not only easier to suppress higher‐order modes than the circular SIW cavity, but also easier to cascade multiple cavities. Two kinds of miniaturization filters are realized by using dual‐layer and single‐layer half‐mode structures, respectively. Dual‐layer triple‐band filter is realized by using TM110, TM120, and TM210. The single‐layer triple‐band filter based on half‐mode SSIW is proposed for further miniaturization. It adopts higher order modes (TM110, TM120, and TM310) to achieve triple‐band response. Moreover, it introduces a W‐shaped coupling slotline, which not only makes lower original resonant frequencies, but also increases the coupling strengths. Source and load coupling (S‐L‐C) and CSRR are introduced for improving the selectivity of the proposed two filters. Finally, both filters have been fabricated. The measured results are in line with the simulated ones.
Angularly stable and broadband chiral metamaterial based design for asymmetric transmission of linearly polarized waves
Authors: Ullah Tariq , Rashid Aamir
Published: August 2020

In this paper, a novel bi‐layered chiral metamaterial (CMM) based design is proposed, which exhibits broadband operation of asymmetric transmission (AT) of linearly polarized waves. Simulation results of the proposed design shows wide‐band AT response (transmission efficiency greater than 90%) in the microwave region from 8.48 to 10.16 GHz (1.68 GHz bandwidth) with a simultaneous cross‐polarization conversion (CPC) response (conversion efficiency greater than 92%). The transmission and reflection response clearly indicate the AT and CPC results of our design. Both behaviors are explained in terms of cross‐coupling between induced electric and magnetic dipoles due to surface currents. Finally, it is shown that AT response of the proposed design is stable with respect to variations in incident angle of the incoming wave up to 45°. Due to its high efficiency, low‐profile, broadband response, and angular stability this design has numerous applications in modern telecommunication systems.
Enhancing stability of CsPbBr3 nanocrystals light‐emitting diodes through polymethylmethacrylate physical adsorption
Authors: Wang Zhaojin , Xiao Xiangtian , Shen Jian , Liu Pai , Wu Dan , Tang Xiaobing , Mei Guanding , Sun Jiayun , Yang Hongcheng , Li Xiang , Wu Zhenghui , Xie Qifei , Fang Fan , Ding Shihao , Choy Wallace C.H. , Sun Xiao Wei , Wang Kai
Published: August 2020

Boosting the efficiency and lifetime of all inorganic metal halide perovskite nanocrystals (PeNCs) based light‐emitting diodes (PeLEDs) will promote the application of PeNCs in displays and lighting. However, achieving high‐stability CsPbBr3 NCs is still a critical challenge. In this study, a physical adsorption of polymethylmethacrylate (PMMA) on the surface of CsPbBr3 NCs is proven effective to enhance CsPbBr3 NCs stability by reducing the surface energy and preventing the attack of water and oxygen molecules. It also alleviates the energy transfer between neighboring NCs and greatly reduces the thin film roughness by suppressing the agglomeration of the CsPbBr3 NCs within films. Specifically, compared with CsPbBr3 NCs without PMMA adsorption, the photostability under the illumination of continuous ultraviolet light (96 hours) and storage stability under 0 °C (60 days) of the proposed CsPbBr3 NCs with PMMA adsorption are therefore improved by >10 times and four times, respectively. Moreover, since the energy transfer between CsPbBr3 NCs and the agglomeration of CsPbBr3 NCs within films have been suppressed dramatically by the physical absorbed PMMA, the maximum luminance of as‐fabricated LED devices is promoted from 5000 to 13,800 cd m−2 with alleviated roll‐off effect. The operational lifetime of the LED devices is also improved by 5.7 times owing to PMMA preventing the attack of water and oxygen molecules.
Validity and accuracy of calculating oxidative ATP synthesis in vivo during high‐intensity skeletal muscle contractions
Authors: Bartlett Miles F. , Fitzgerald Liam F. , Nagarajan Rajakumar , Kent Jane A.
Published: August 2020

Several methods have been developed for using 31P‐MRS to calculate rates of oxidative ATP synthesis (ATPOX) during muscular contractions based on assumptions that (1) the ATP cost of force generation (ATPCOST) remains constant or (2) Michaelis‐Menten coupling between cytosolic ADP and ATPOX does not change. However, growing evidence suggests that one, or both, of these assumptions are invalid during high‐intensity fatigue protocols. Consequently, there is a need to examine the validity and accuracy of traditional ATPOX calculation methods under these conditions. To address this gap, we measured phosphate concentrations and pH in the vastus lateralis muscle of nine young adults during four rest‐contraction‐recovery trials lasting 24, 60, 120, and 240 s. The initial velocity of phosphocreatine resynthesis (ViPCr) following each trial served as the criterion measure of ATPOX because this method makes no assumptions of constant ATPCOST or Michaelis‐Menten coupling between changes in cytosolic ADP and ATPOX. Subsequently, we calculated ATPOX throughout the 240 s trial using several traditional calculation methods and compared estimations of ATPOX from each method with time‐matched measurements of ViPCr. Method 1, which assumes that ATPCOST does not change, was able to model changes in ViPCr over time, but showed poor accuracy for predicting ViPCr across a wide range of ATPOX values. In contrast, Michaelis‐Menten methods, which assume that the relationship between changes in cytosolic ADP and ATPOX remains constant, were invalid because they could not model the decline in ViPCr. However, adjusting these Michaelis‐Menten methods for observed changes in maximal ATPOX capacity (i.e., Vmax) permitted modeling of the decline in ViPCr and markedly improved accuracy. The results of these comprehensive analyses demonstrate that valid, accurate measurements of ATPOX can be obtained during high‐intensity contractions by adjusting Michaelis‐Menten ATPOX calculations for changes in Vmax observed from baseline to post‐fatigue.
On a new centered strategy to control the accuracy of weighted essentially non oscillatory algorithm for conservation laws close to discontinuities
Authors: Amat Sergio , Baeza Antonio , Ruiz Juan , Shu Chi‐Wang
Published: August 2020

In this paper we try to redesign an algorithm analyzed in previous works by Amat et al. in order to obtain a centered strategy aimed to approximate the solution of linear and nonlinear systems of conservation laws. We perform the analysis of the new algorithm in order to explain why the new strategy works close to shocks in the solution of conservation laws. The objective is to force the use of the most centered stencil of those used whenever the data are affected by the presence of a high gradient.
Numerical and theoretical study of weak Galerkin finite element solutions of Turing patterns in reaction–diffusion systems
Authors: Khaled‐Abad Leila Jafarian , Salehi Rezvan
Published: August 2020

In this paper, we introduce numerical schemes and their analysis based on weak Galerkin finite element framework for solving 2‐D reaction–diffusion systems. Weak Galerkin finite element method (WGFEM) for partial differential equations relies on the concept of weak functions and weak gradients, in which differential operators are approximated by weak forms through the Green's theorem. This method allows the use of totally discontinuous functions in the approximation space. In the current work, the WGFEM solves reaction–diffusion systems to find unknown concentrations (u, v) in element interiors and boundaries in the weak Galerkin finite element space WG(P0, P0, RT0). The WGFEM is used to approximate the spatial variables and the time discretization is made by the backward Euler method. For reaction–diffusion systems, stability analysis and error bounds for semi‐discrete and fully discrete schemes are proved. Accuracy and efficiency of the proposed method successfully tested on several numerical examples and obtained results satisfy the well‐known result that for small values of diffusion coefficient, the steady state solution converges to equilibrium point. Acquired numerical results asserted the efficiency of the proposed scheme.
Revisiting the economic growth and agriculture nexus in Nigeria: Evidence from asymmetric cointegration and frequency domain causality approaches
Authors: Agboola Mary Oluwatoyin , Bekun Festus Victor , Osundina Olawumi Abeni , Kirikkaleli Dervis
Published: August 2020

The contribution of different agricultural subsectors to economic growth in Nigeria is investigated and further suggests policy implications for investing in each of these subsectors. To this end, Johansen cointegration test and Gregory–Hansen test for cointegration with regime shift, vector error correction model (VECM), dynamic ordinary least squares (DOLS), fully modified ordinary least squares (FMOLS), Granger causality, and frequency domain causality test are employed for data from 1981 to 2016. This paper further highlights the long and causal dynamics between the selected agricultural subsector, namely forestry, crop production, fishery and livestock, and economic growth. Findings from time and frequency domain causality tests indicate a one‐way causality running from various subsectors of agriculture to economic growth in Nigeria, meaning how various subsectors of agriculture are important for predicting economic growth. In addition, there is 54% speed of adjustment from the error correction model, suggesting a need for diversification of the economy into the agricultural sector as a means for sustainable economic growth in the face of the continuous plunge in the global oil price. In the long‐run, the effect of forestry, crop production, and fishery on economic growth is statistically significant and positive. These outcomes have inherent policy implication(s), which are elucidated in the concluding section.
The role of institutional ownership structures on corporate performance
Authors: Hussain Muzzammil , Abid Fareeha , Ambreen Syeda , Usman Ahmad , Rahman Atteeq ur
Published: August 2020

Institutional investors are the key investors in stock markets. Stock markets are influenced by these giants. We investigate the comparative institutional ownership structure in financial and non‐financial corporations. Institutional ownership structures are foreign, domestic, state, and private institutional ownership, which are examined against the corporate performance of 40 firms listed in Pakistan Stock Exchange from 2006 to 2016. Panel regression is applied to observe the results. Varied impacts for every category of institutional ownership in financial and non‐financial firms are evident. The findings of the study are robust, and potential investors can use this study for their future investment plans. Investor institutions can decide their future investment directions in Pakistan.
Comparative analysis of mechanical behavior of 3D woven spacer sandwich composites with single and double level structures
Authors: Neje Ghanshyam , Behera Bijoya Kumar
Published: August 2020

3D woven spacer fabrics connected with woven cross‐links and forming tunnels of trapezoidal shape were produced in single and double level configuration with four different cell wall opening angles in each configuration. The sandwich composites produced from these spacer fabrics were then analyzed for their out‐of‐plane compressive and flexural properties to study their failure loads, energy absorbency, and failure modes. With an increase in the cell wall opening angles, compressive load and specific compressive load increased for single and double level structures, but the same properties were found to be poor for double level structures compared to their single level counterparts. Absorbed energy/volume was also found to be lower for double level composites. The bending load and specific bending load values increased with increase in cell wall opening angle, with double level structures performing better at each cell wall opening compared to their single level counterparts. But the flexural stress of double level structures was lower than that of their corresponding single level structures. The outcomes of this study can be used in designing and manufacturing of multilevel spacer structures with different cell geometrical parameters for specific end use requirements.
Fabrication and investigation on damping performance of novel co‐curing sandwich composites
Authors: Zheng Changsheng , Liang Sen
Published: August 2020

A new kind of co‐cured sandwich composite was manufactured via inserting tailored damping materials between the lamina to enhance vibration characteristics and sound insulation performance of traditional sandwich composite. The sandwich material was investigated based on the theory of co‐curing, which was superior to the preparation process of traditional sandwich composite. The viscous flow characteristics of epoxy resin and rubber sandwich were considered in the preparation process. The damping characteristics and sound insulation properties of the sandwich composite were determined by the single cantilever beam vibration test and the standing wave tube method. The loss factor of the sandwich composites with damping layer thickness of 0.1 mm reaches 3.384%, which increases by 102.81% compared with that of the undamped composite. The experimental results reveal that the novel damping polymer enhances the damping characteristic and sound insulation performance of laminates significantly compared with previous sandwich composite. The conclusion indicates that the co‐cured composite structures show a strong ability of vibration reduction and sound insulation.
InGaN/GaN multi‐quantum‐well solar cells under high solar concentration and elevated temperatures for hybrid solar thermal‐photovoltaic power plants
Authors: Moses Gilad , Huang Xuanqi , Zhao Yuji , Auf der Maur Matthias , Katz Eugene A. , Gordon Jeffrey M.
Published: August 2020

Hybrid solar electricity generation combines the high efficiency of photovoltaics (PVs) with the dispatchability of solar thermal power plants. Recent thermodynamic analyses have shown that the most efficient strategy constitutes an integrated concentrating PV‐thermal absorber operating at high solar concentration and at the high temperatures suitable to efficient commercial steam turbines (~673–873 K). The recuperation of PV thermalization losses and the exploitation of sub‐bandgap photons can more than compensate for the inherent decrease of PV efficiency with temperature in properly tailored tandem solar cells for which promising candidates are III–N alloys. Recently, there have been considerable efforts to develop apposite InGaN solar cells by producing InGaN/GaN multiple quantum wells (MQWs) as the top cell in a tandem PV device that would absorb the short‐wavelength regime of the solar spectrum, while sub‐bandgap photons and PV thermalization are absorbed in the thermal receiver.

We present measurements of current–voltage curves and external quantum efficiency spectra for InGaN/GaN MQW solar cells under high sunlight intensity, up to 1 W/mm2 (1000 suns) and elevated temperature, up to 723 K. We find that the short‐circuit current increases significantly with temperature, while the magnitude of the temperature coefficient of the open‐circuit voltage decreases with solar concentration according to basic photodiode theory. Conversion efficiency peaks at 623–723 K under ~300 suns, with no perceptible worsening in cell performance under extensive temperature and irradiance cycling—an encouraging finding in the quest for high‐temperature high‐irradiance cells.
Towards improved cover glasses for photovoltaic devices
Authors: Allsopp Benjamin L. , Orman Robin , Johnson Simon R. , Baistow Ian , Sanderson Gavin , Sundberg Peter , Stålhandske Christina , Grund Lina , Andersson Anne , Booth Jonathan , Bingham Paul A. , Karlsson Stefan
Published: August 2020

For the solar energy industry to increase its competitiveness, there is a global drive to lower the cost of solar‐generated electricity. Photovoltaic (PV) module assembly is material‐demanding, and the cover glass constitutes a significant proportion of the cost. Currently, 3‐mm‐thick glass is the predominant cover material for PV modules, accounting for 10%–25% of the total cost. Here, we review the state‐of‐the‐art of cover glasses for PV modules and present our recent results for improvement of the glass. These improvements were demonstrated in terms of mechanical, chemical and optical properties by optimizing the glass composition, including addition of novel dopants, to produce cover glasses that can provide (i) enhanced UV protection of polymeric PV module components, potentially increasing module service lifetimes; (ii) re‐emission of a proportion of the absorbed UV photon energy as visible photons capable of being absorbed by the solar cells, thereby increasing PV module efficiencies and (iii) successful laboratory‐scale demonstration of proof of concept, with increases of 1%–6% in Isc and 1%–8% in Ipm. Improvements in both chemical and crack resistance of the cover glass were also achieved through modest chemical reformulation, highlighting what may be achievable within existing manufacturing technology constraints.
Phaseolus vulgaris SUT1.1 is a high affinity sucrose‐proton co‐transporter
Authors: Santiago James P. , Ward John M. , Sharkey Thomas D.
Published: August 2020

Plant sucrose transporters are required for phloem loading, and therefore are essential for plant growth and development. In common beans (Phaseolus vulgaris) there are only two sucrose transporters functionally characterized. Through a previous RNA‐seq study, we identified a putative sucrose transporter in common bean, which we hypothesize to function in import of sucrose into plant cells. In silico analysis revealed that PvSUT1.1 is a putative sucrose‐proton co‐transporter distinct from other characterized sucrose transporters in common bean indicating that this is a previously undescribed transporter protein in beans. Further analysis revealed that PvSUT1.1 shares high protein sequence homology to the phloem loader Arabidopsis SUC2; both have 12 transmembrane domains, a typical characteristic of plant sucrose transporters. Heterologous expression in yeast further showed PvSUT1.1 to be functional and it imported sucrose into yeast cells with a Km of 0.7 mM sucrose. Import of sucrose through PvSUT1.1 is also pH‐dependent with highest uptake at pH 4.0, and activity is lost in the presence of the uncoupler carbonyl cyanide 3‐chlorophenylhydrazone. Consistent with identification of PvSUT1.1 as a Type I transporter, PvSUT1.1 also transports esculin. Finally, PvSUT1.1 showed expression in multiple tissues and the protein was localized to the plasma membrane. The results show that PvSUT1.1 is a sucrose transporter that is probably involved in the uptake of sucrose into source and sink cells. The potential role of PvSUT1.1 in leaf phloem loading of sucrose in common beans and its importance in heat tolerance of reproductive tissues are further discussed.
Influence of additive on the aggregation behavior of drug and cationic hydrotrope aniline hydrochloride mixtures: a physicochemical assessment
Authors: Alghamdi Yousef G. , Rub Malik Abdul , Azum Naved , Asiri Abdullah M.
Published: August 2020

We investigated the influence of an additive (50 mmol kg–1 NaCl/300 mmol kg–1 urea [U]) on the aggregation of amphiphilic promethazine hydrochloride (PMH) drug and cationic hydrotrope–aniline hydrochloride (AnHCl) mixtures at various temperatures and ratios. The drug PMH is mostly used for the treatment of allergic symptoms. The obtained critical micelle concentration (cmc) values are well below the cmcid (ideal cmc) value, which confirms interactions between components PMH and AnHCl in the solution mixture. The micellar mole fraction (X1Rub, X1Rod, and X1id) of the first component (AnHCl) was evaluated using different models, which suggested greater involvement of AnHCl in mixed micelles (as expected); besides, the obtained micellar mole fraction values increase with increase in the mole fraction (α1) of AnHCl. The interaction parameter (β) values obtained were negative, which confirms attractive interaction or synergism among the components. Activity coefficients (
[AnHCl] and
[PMH]) values are always found below one confirming the nonideality as well as attractive interaction between the components. Different physicochemical parameters evaluated suggested attractive interaction between the components (PMH and AnHCl) in all studied solvents; however, in salt media, the interaction increases to some extent, whereas in urea media, it decreases to some extent. Diverse thermodynamic parameters (Gibbs free energy [ΔGm0], enthalpy [ΔHm0], and entropy [ΔSm0]) of micellization were computed and discussed separately. The excess free energy (
) values of all systems were negative, suggesting higher stability of formed mixed micelles as compared with singular‐component micelles.
Alkaline‐developable and negative‐type photosensitive polyimide with high sensitivity and excellent mechanical properties using photo‐base generator
Authors: Tseng Ling‐Ya , Lin Yan‐Cheng , Kuo Chih‐Cheng , Chen Chun‐Kai , Wang Chuan‐En , Kuo Chi‐Ching , Ueda Mitsuru , Chen Wen‐Chang
Published: August 2020

An alkaline developable and negative‐type PSPI with a high sensitivity and excellent mechanical properties based on a poly(amic acid) (PAA) and a photo‐base generator has been developed. The PAA was prepared by the polycondensation of p‐phenylenediamine (PDA) with an equimolar of 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA) and 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6‐FDA) and converted thermally to the corresponding polyimide, PI(PDA‐BPDA/6‐FDA). PI(PDA‐BPDA/6‐FDA) showed the high thermal and mechanical properties and the dimensional stability such as the thermal decomposition temperature of 530°C, glass transition temperature of 369°C, linear coefficient of thermal expansion of 28 ppm/K, ultimate tensile strength of 148 MPa, elongation at break of 25% and dielectric constant of 2.8. The PSPI was formulated directly from PAA(PDA‐BPDA/6‐FDA) with a photo‐base generator (PBG), (E)‐3‐(2‐hydroxy‐4‐methoxyphenyl)‐1‐(piperidin‐1‐yl)prop‐2‐en‐1‐one (HMPP) (10 wt% to PAA) and the optimized parameters for photolithographic process were investigated including the PBG content, post‐exposure bake (PEB) temperature, and PEB time. The PSPI based on PAA(PDA‐BPDA/6‐FDA) and HMPP (10 wt% to PAA) showed a sensitivity of 114 mJ/cm2 and contrast of 1.29 when exposed to 365‐nm light (i‐line), post‐exposure baked at 160°C for 5 min, and developed with an aqueous solution of 2.38 wt% tetramethylammonium hydroxide and iso‐propanol. A clear negative 8‐μm features pattern was obtained by contact‐printing and converted into the PI pattern upon heating at 250°C, confirming by scanning electron microscopy and infrared spectroscopy.
Nitroxide mediated miniemulsion polymerization of methacryloisobutyl POSS: Homopolymers and copolymers with alkyl methacrylates
Authors: Tajbakhsh Saeid , Marić Milan
Published: August 2020

Nitroxide mediated polymerization (NMP) of methacryloisobutyl POSS (POSSMA) was conducted in a dispersed aqueous miniemulsion at 90°C, resulting in stable latexes with particle sizes = 225–260 nm at solids loading = 22%. POSSMA homopolymers with up to 35.9 kg mol−1 (Đ < 1.53) was prepared using Dispolreg 007 alkoxyamine without any controlling comonomers, as is traditionally required for NMP of methacrylates. Copolymers with different ratios of POSSMA and bio‐based C13 methacrylic esters were also synthesized (monomer conversion [X] up to 96.5% and 1.42 < Đ < 1.68) to prepare polymer resins with a wide range of glass transition temperatures (Tg) or melting points (Tm) (−30°C < Tg, Tm < 96°C). The resulting homopolymers and copolymers exhibited semi‐crystalline properties, with crystallite size of 20.3–44.4 Å.
A systematic review of tools used to assess body image, masculinity and self‐esteem in men with prostate cancer
Authors: Bowie Jessica , Brunckhorst Oliver , Stewart Robert , Dasgupta Prokar , Ahmed Kamran
Published: August 2020

Objective

Masculinity, body image and self‐esteem are important interlinked factors affecting prostate cancer (PCa) patients' quality of life. The aim of this systematic review was to identify and evaluate all tools measuring these domains in men with PCa.

Methods

This review was conducted according to PRISMA guidelines with a priori protocol registered. Pubmed, Embase, Medline and Psychinfo were searched from inception to May 2020. Studies using a predefined tool which measured any body image, self‐esteem or masculinity construct in men with PCa were included, as well as validation studies of these. Reliability, validity and responsiveness of tools identified were objectively evaluated against the COSMIN taxonomy of measurement properties.

Results

From 1416 records screened, a final 46 studies consisting of 17 different tools were included in the systematic review. Seven tools were identified assessing body image, nine masculinity and one self‐esteem, varying widely in their number of items, possible responses and domains assessed. Most tools had evaluated internal consistency through Cronbach's alpha analysis; however, structural and discriminative validity, and responsiveness were lacking for many. Additionally, only one tool identified was specifically developed and evaluated in patients with PCa: The Masculinity in Chronic Disease Inventory.

Conclusions

Numerous tools have been used for the measurement of body image, masculinity and self‐esteem in men with PCa. However, few were developed specifically for these patients. More research is therefore needed to ascertain specific factors affecting these outcomes in PCa patients, so valid, reliable and clinically relevant tools can be developed.
Moderators of the effect of psychosocial interventions on fatigue in women with breast cancer and men with prostate cancer: Individual patient data meta‐analyses
Authors: Abrahams Harriët J. G. , Knoop Hans , Schreurs Maartje , Aaronson Neil K. , Jacobsen Paul B. , Newton Robert U. , Courneya Kerry S. , Aitken Joanne F. , Arving Cecilia , Brandberg Yvonne , Chambers Suzanne K. , Gielissen Marieke F.M. , Glimelius Bengt , Goedendorp Martine M. , Graves Kristi D. , Heiney Sue P. , Horne Rob , Hunter Myra S. , Johansson Birgitta , Northouse Laurel L. , Oldenburg Hester S.A. , Prins Judith B. , Savard Josée , van Beurden Marc , van den Berg Sanne W. , Verdonck‐de Leeuw Irma M. , Buffart Laurien M.
Published: August 2020

Objective

Psychosocial interventions can reduce cancer‐related fatigue effectively. However, it is still unclear if intervention effects differ across subgroups of patients. These meta‐analyses aimed at evaluating moderator effects of (a) sociodemographic characteristics, (b) clinical characteristics, (c) baseline levels of fatigue and other symptoms, and (d) intervention‐related characteristics on the effect of psychosocial interventions on cancer‐related fatigue in patients with non‐metastatic breast and prostate cancer.

Methods

Data were retrieved from the Predicting OptimaL cAncer RehabIlitation and Supportive care (POLARIS) consortium. Potential moderators were studied with meta‐analyses of pooled individual patient data from 14 randomized controlled trials through linear mixed‐effects models with interaction tests. The analyses were conducted separately in patients with breast (n = 1091) and prostate cancer (n = 1008).

Results

Statistically significant, small overall effects of psychosocial interventions on fatigue were found (breast cancer: β = −0.19 [95% confidence interval (95%CI) = −0.30; −0.08]; prostate cancer: β = −0.11 [95%CI = −0.21; −0.00]). In both patient groups, intervention effects did not differ significantly by sociodemographic or clinical characteristics, nor by baseline levels of fatigue or pain. For intervention‐related moderators (only tested among women with breast cancer), statistically significant larger effects were found for cognitive behavioral therapy as intervention strategy (β = −0.27 [95%CI = −0.40; −0.15]), fatigue‐specific interventions (β = −0.48 [95%CI = −0.79; −0.18]), and interventions that only targeted patients with clinically relevant fatigue (β = −0.85 [95%CI = −1.40; −0.30]).

Conclusions

Our findings did not provide evidence that any selected demographic or clinical characteristic, or baseline levels of fatigue or pain, moderated effects of psychosocial interventions on fatigue. A specific focus on decreasing fatigue seems beneficial for patients with breast cancer with clinically relevant fatigue.