bluuebunny/crossref_metadata_2025 huggingface dataset:
Kink as a new degree of freedom to tune the thermal conductivity of Si nanoribbons
Authors: Yang Lin , Zhang Qian , Wei Zhiyong , Cui Zhiguang , Zhao Yang , Xu Terry T. , Yang Juekuan , Li Deyu
Published: October 2019

An attractive feature of nanomaterials is the possibility of tuning their properties through controlling their size and surface morphology, and understanding the effects of various parameters on thermal transport properties of nanostructures has been an active research topic in the past two decades. Through systematic studies of kinked silicon nanoribbons, we show how the kink morphology, a newly recognized degree of freedom for tuning thermal transport in nanostructures, modulates the thermal conductivity of these nanoribbons. For kinked Si nanoribbons that are 34 nm thick and 141 nm wide, the measured thermal conductivity first decreases as the period length reduces from 2 μm to 0.5 μm, reaching a 21% thermal conductivity reduction as compared to that of a straight counterpart at 300 K. However, as the period length drops to a level at which a straight heat transfer channel opens between the heat source and the sink, the thermal conductivity exhibits a steep increasing trend. Moreover, the comparison of thermal conductivity reduction for kinked ribbons along different crystalline directions indicates that phonon focusing could be exploited to further suppress thermal transport in kinked silicon nanoribbons. These results provide important guidelines on modulating heat transfer in nanostructures using kinks, which could be adopted to tune the thermal properties of nanostructures for different applications, such as thermoelectrics, microelectronic device thermal management, and functional thermal regulators.
Reaction coordinates and rate constants for liquid droplet nucleation: Quantifying the interplay between driving force and memory
Authors: Tsai Sun-Ting , Smith Zachary , Tiwary Pratyush
Published: October 2019

In this work, we revisit the classic problem of homogeneous nucleation of a liquid droplet in a supersaturated vapor phase. We consider this at different extents of the driving force, or equivalently the supersaturation, and calculate a reaction coordinate (RC) for nucleation as the driving force is varied. The RC is constructed as a linear combination of three order parameters, where one accounts for the number of liquidlike atoms and the other two for local density fluctuations. The RC is calculated from biased and unbiased molecular dynamics (MD) simulations using the spectral gap optimization approach “SGOOP” [P. Tiwary and B. J. Berne, Proc. Natl. Acad. Sci. U. S. A. 113, 2839 (2016)]. Our key finding is that as the supersaturation decreases, the RC ceases to simply be the number of liquidlike atoms, and instead, it becomes important to explicitly consider local density fluctuations that correlate with shape and density variations in the nucleus. All three order parameters are found to have similar barriers in their respective potentials of mean force; however, as the supersaturation decreases, the density fluctuations decorrelate slower and thus carry longer memory. Thus, at lower supersaturations, density fluctuations are non-Markovian and cannot be simply ignored from the RC by virtue of being noise. Finally, we use this optimized RC to calculate nucleation rates in the infrequent metadynamics framework and show that it leads to a more accurate estimate of the nucleation rate with four orders of magnitude acceleration relative to unbiased MD.
Chaotic transport of navigation satellites
Authors: Gkolias Ioannis , Daquin Jérôme , Skoulidou Despoina K. , Tsiganis Kleomenis , Efthymiopoulos Christos
Published: October 2019

Navigation satellites are known from numerical studies to reside in a dynamically sensitive environment, which may be of profound importance for their long-term sustainability. We derive the fundamental Hamiltonian of Global Navigation Satellite System dynamics and show analytically that near-circular trajectories lie in the neighborhood of a Normally Hyperbolic Invariant Manifold (NHIM), which is the primary source of hyperbolicity. Quasicircular orbits escape through chaotic transport, regulated by NHIM’s stable and unstable manifolds, following a power-law escape time distribution P(t)∼t−α, with α∼0.8−1.5. Our study is highly relevant for the design of satellite disposal trajectories, using manifold dynamics.
An information-theoretic approach to extracting climate signals from deep polar ice cores
Authors: Garland Joshua , Jones Tyler R. , Neuder Michael , White James W. C. , Bradley Elizabeth
Published: October 2019

Paleoclimate records are rich sources of information about the past history of the Earth system. Information theory provides a new means for studying these records. We demonstrate that weighted permutation entropy of water-isotope data from the West Antarctica Ice Sheet (WAIS) Divide ice core reveals meaningful climate signals in this record. We find that this measure correlates with accumulation (meters of ice equivalent per year) and may record the influence of geothermal heating effects in the deepest parts of the core. Dansgaard-Oeschger and Antarctic Isotope Maxima events, however, do not appear to leave strong signatures in the information record, suggesting that these abrupt warming events may actually be predictable features of the climate’s dynamics. While the potential power of information theory in paleoclimatology is significant, the associated methods require well-dated and high-resolution data. The WAIS Divide core is the first paleoclimate record that can support this kind of analysis. As more high-resolution records become available, information theory could become a powerful forensic tool in paleoclimate science.
Systematic approach approximates exchange correlation potentials more accurately and applicably
Authors: Liebendorfer Adam
Published: October 2019

Force-balance equations allow determining exchange correlation potentials without using energy or action expressions.
How kinks can tune the thermal conductivity of silicon nanoribbons
Authors: Patrick Chris
Published: October 2019

Experimental and numerical studies reveal the underlying mechanisms of how kink morphology modulates the thermal conductivity of nanoribbons.
Tunneling field effect transistors provide insight into graphene charges at high magnetic fields
Authors: Bandari Anashe
Published: October 2019

New technique enables the exploration of graphene states at high magnetic fields, allowing for the direct study of graphene’s electronic structure under extreme experimental conditions.
Cross slip not key deformation in explosive molecular crystal
Authors: Patrick Chris
Published: October 2019

Simulations show cross slip is not a very important deformation mechanism for the widely used explosive cyclotetramethylene tetranitramine.
Excitonic Processes in a Conjugated Polyelectrolyte Complex
Authors: Nitneth David T. , Hutchison James A. , Ghiggino Kenneth P.
Published: October 2019

In aqueous solution, a di-sulfonated phenylenevinylene polymer (DPS-PPV) forms a complex with non-ionic poly(vinyl alcohol) (PVA) leading to absorption spectroscopic shifts and a dramatic (6-fold) increase in DPS-PPV fluorescence intensity. Spectroscopic investigations demonstrate that the complexation with PVA and other neutral polymers results in conformational changes in the DPS-PPV chains that lead to the removal of non-fluorescent energy traps and results in the observed increase in fluorescence in the bulk solution. Single molecule fluorescence measurements of DPS-PPV chains dispersed on glass and in PVA films confirm that efficient exciton energy transfer occurs within each photo-excited DPS-PPV chain and that the observed increase in fluorescence intensity in the PVA film environment is also associated with fewer quenching sites. The results highlight the importance of conjugated polyelectrolyte conformation on exciton relaxation pathways.
Socioecological differences in factors associated with inconsistent condom use with female sex workers and casual partners: an observational study of heterosexual men attending an anonymous HIV testing clinic in Singapore
Authors: Takashima K. , Yeoh G. W. J. , Chua H. E. , Ting P. L. M. , Chong J. Y. , Tan R. K. J. , Kaur N. , Mohdar L. H. , Banerjee S. , Chan R. K. W. , Chen M. I. , Wong C. S.
Published: October 2019

Sexual practices among heterosexual men may differ between female sex workers (FSWs) and casual partners. We surveyed 203 heterosexual men and investigated the attributes associated with inconsistent condom use among them. Lower educational attainment was positively associated with inconsistent condom use with FSWs (adjusted prevalence ratio (aPR) 2.63; P = 0.018) and casual partners (aPR 1.55; P = 0.022), whereas early age of sexual debut (aPR 3.00; P = 0.012) and alcohol use during sex (aPR 7.95; P < 0.001) were positively associated with inconsistent condom use with FSWs. Socioecological factors may explain such differences.
Effects of fuel characteristics on ember generation characteristics at branch-scales
Authors: Hudson Tyler R. , Blunck David L.
Published: October 2019

Spot fires caused by lofted embers (i.e. firebrands) can be a significant factor in the spread of wildfires. Embers can be especially dangerous near the wildland–urban interface (WUI) because of the potential for the fire to be spread near or on structures. This work sought to identify how ember generation changes for different fuel characteristics and environmental conditions. Samples were burned in a heated wind tunnel and the time required for the ember(s) to form was measured using a DSLR camera. A factorial analysis of variance was used to determine the sensitivity of the time to generation to species, diameter, moisture content, fuel condition (i.e. dowel v. natural sample), crossflow temperature and crossflow velocity. Four fuel species were evaluated: Douglas fir (Pseudotsuga menziesii), western juniper (Juniperus occidentalis), ponderosa pine (Pinus ponderosa) and white oak (Quercus alba). The diameter of the samples had the greatest effect on the time to generation and the fuel species had the second greatest effect. The small diameter samples were relatively insensitive to changes in other parameters. Natural samples required significantly longer time than dowels to generate an ember. These conclusions suggest that fuel morphology is one of the most significant factors influencing ember generation.
“The murderer is him ✓”
Authors: Zhang Leticia Tian , Cassany Daniel
Published: October 2019

This paper analyzes humorous comments created through a popular viewing-and-commenting system used in China and Japan, known asdanmu(ordanmaku). This system enables its users to superimpose anonymous comments on the video frame, which are displayed in subsequent viewing. We collected 327 user-selected ‘funniest’ screenshots of comments fromdanmuvideo sharing sites. Using content and discourse analysis, we re-contextualized the comments and identified main mechanisms of humor. Results show that speakers make fun of the plot, characters and of each other, relating to the video frame, Chinese culture and Japanese fandom. They rely on non-aggressive but rather playful teasing, allusions and retorts, and apply multimodal resources such as color, layout, and symbols to enhance the humorous effect. Our study contributes to the emerging research focus on multimodal humor (Yus 2016), social semiotics and a discursive approach todanmu-mediated communication.
Properties of intrinsic point defects and dimers in hexagonal boron nitride
Authors: Strand Jack , Larcher Luca , Shluger Alexander L
Published: October 2019

Hexagonal boron nitride (hBN) is a wide gap 2D layered material with good insulating properties. Intrinsic point defects in hBN play an important role in its applications as a dielectric in 2D electronic devices. However, the electronic properties of these defects are still poorly understood. We have calculated the structure and properties of a wide range of intrinsic point defects in the bulk of hBN using hybrid density functional theory (DFT). These include vacancies and interstitial states of B and N as well as di- and tri-vacancies. For each isolated defect, multiple charge states are calculated, and for each charge state multiple spin states are investigated. Positions of defect charge transition levels in the band gap of hBN are calculated. In particular, we predict that B vacancies are likely to be negatively charged in contact with graphene and other metals. Calculations of the interaction between vacancies predict that divacancies in both B and N sublattices are strongly binding. Moreover, the interaction of single B and N vacancies in adjacent layers induces the creation of -N–N- and -B–B- molecular bridges, which greatly distort the local structure, leading to local bond weakening. These results provide further insight into the properties of defects which can be responsible for degradation of hBN based devices.
Macroscopical model of streamer coronas around a spherical electrode
Authors: González M , Gordillo-Vázquez F J , Luque A
Published: October 2019

We present a model for streamer coronas emerging from a spherical electrode at high electrostatic potential. By means of a macroscopic streamer model and approximating the corona as a set of identical streamers with a prescribed spatial distribution around the electrode, we establish that coronas more densely packed with streamers are slower and more efficient at screening the electric field inside the streamers. We also apply our model to investigate the electrostatic potential at the boundary of the corona sheath that surrounds a leader and we underline the relevance of the rise-time of the leader potential during a leader step.
Neuro-fuzzy mid-term forecasting of electricity consumption using meteorological data
Authors: Adedeji Paul A. , Akinlabi Stephen , Madushele Nkosinathi , Olatunji Obafemi
Published: October 2019

Forecasting energy consumption is highly essential for strategic and operational planning. This study uses the Adaptive-Neuro-Fuzzy Inference System (ANFIS) for a midterm forecast of electricity consumption. The model comprises of three meteorological variables as inputs and electricity consumption as output. Two ANFIS models with two clustering techniques (Fuzzy c-Means (FCM) and Grid Partitioning (GP) were developed (ANFIS-FCM and ANFIS-GP) to forecast monthly energy consumption based on meteorological variables. The performance of each model was determined using known statistical metrics. This compares the predicted electricity consumption with the observed and a statistical significance between the two reported. ANFIS-FCM model recorded a better mean absolute deviation (MAD), root mean square (RMSE), and mean absolute percentage error (MAPE) values of 0.396, 0.738, and 8.613 respectively compared to the ANFIS-GP model, which has MAD, RMSE, and MAPE values of 0.450, 0.762, and 9.430 values respectively. The study established that FCM is a good clustering technique in ANFIS compared to GP and recommended a comparison between the two techniques on hybrid ANFIS model.
Technology usage and employee behaviour: controversies, complications, and implications in the Nigerian business environment
Authors: Agboola Mayowa G , Akinbode Mosunmola , Segun-Adeniran Chidi , Ifeanyichukwu Dibia Peter , Oloruntoba Anuoluwapo , Dinyain Tamarapreye , Johnson Fabunmi Tolulope , Funsho Temitope , Abayomi Akinde Oluwaseun , Betek Chelsea M
Published: October 2019

Organizations are among the key units of the society. An organization comprises of several people including employees. The behaviour of employees determines the performance and efficiency of the organization. Technology is an important factor that distinguishes one organization from the other. Employee’s acceptance, rejection, and adaptability to technology being used determine to a great extent how organizations will thrive in a business environment. The drive of technology usage is to ensure that work processes are made easier, faster and to improve the organization’s economic efficiency. In addition, technology usage greatly influences employee behaviour. The aim of this paper is to find out how technology usage affects employee behaviour and vice versa. It is important to understand that in order to improve employee’s usage of technology incorporated into the organization, individual behaviour of employees must be examined cum their attitude. The results of the study indicate that employee behaviour mainly affects technology usage, promotes individual learning, increases efficiency and effectiveness, and improves organizational performance. The paper therefore recommends periodic review of organizational policies and in addition, procure hardware and software to guide against hackers and scammers to avoid losing those important information.
Thermal Degradation and Spectroscopic study of Neat Palm Oil, Waste Palm Oil, and Waste Palm Oil Methyl Ester
Authors: Awogbemi Omojola , Onuh Emmanuel I , Komolafe Clement A
Published: October 2019

Research into finding an affordable, renewable, biodegradable and environmentally friendly alternative fuel to power compression ignition engine has been intensified in the past few decades. The application of waste palm oil (WPO) as feedstock for biodiesel has gained traction and has led to a decline in the production cost of biodiesel, and prevents the contamination of aquatic and terrestrial habitats. The present effort is geared towards characterization of neat palm oil (NPO), WPO and waste palm oil methyl ester (WPOME) through Thermogravimetric analysis (TGA), Derivative thermogravimetric (DTG), and Fourier Transform Infrared Spectroscopy (FTIR). Samples of NPO and WPO were collected from takeaway outlets. The WPO was converted into WPOME by transesterification. The outcome of DTG analysis showed that the vaporization of NPO, WPO, and WPOME occurred between 320 °C and 480 °C; 320 °C and 470 °C, and 27 °C and 103 °C respectively. The TGA analysis revealed that NPO, WPO, and WPOME exhibited similar thermal degradation trend and lost 98 %, 29 %, and 63 % of their weight respectively, during the one stage of thermal degradation. The spectra curve for NPO and WPO followed the same trend and achieve peaks at nearly the same wavelength of 1743 cm−1 while the peculiar peak of the spectra curve for WPOME occurred at 1022 cm−1. In conclusion, this work reinforces that usage and transesterification alters the thermal degradation and spectroscopic pattern of palm oil.
Spectral filtering of photovoltaic cells using novel bio-filter: Silver coated Hibiscus extract using methanol solution
Authors: Emetere M.E. , Nehemiah Adeyemo
Published: October 2019

Spectra filtering is a fairly new concept to control the damaging contributions of solar IR radiations to photovoltaic (PV) cells or panel. In this research, the bio-filter was synthesized and tested. The bio-filter was proposed as the panacea to filtering the solar IR radiations. The bio-filter performance was adjudged to show little success, as it was 3% lower than the normal performance in the monocrystalline solar PV panel and 50% higher than the normal performance in the polycrystalline solar PV panel. The varying results in the polycrystalline and monocrystalline PV panels may arise as a result of unequal coating of the panel. Hence, the coating technique is recommended to be uniform and precise in further research work.
Optimization of solar photovoltaic efficiency using angular inclination: Effect on surface temperature distribution
Authors: Emetere M.E. , Adeyemo N.
Published: October 2019

Temperature distribution over the surface of a solar photovoltaic (PV) panel is essential as over heating lowers the efficiency of the PV module. There have been multiple solutions towards cooling the PV surface during extremely hot sunshine. The mechanism is envisaged to be expensive to construct and maintain. In this research the PV panel was inclined at various degree to determine the best inclination that would allow convective cooling. It was observed that at an inclination of 45°, the convective cooling from surrounding wind was able to regulate the surface temperature. Hence, the sinusoidal trend of thermal heating was distorted significantly-signifying that the convective wind was able to mitigate the PV surface heating.
Monitoring of Background Radiation in Selected Schools in Ota, Ogun State Nigeria by Direct Measurement of Terrestrial Radiation Dose Rate
Authors: Onumejor C. A. , Akinpelu A. , Arijaje T. E. , Usikalu M. R. , Oladapo O. F. , Emetere M. E. , Omeje M. , Achuka J. A.
Published: October 2019

Terrestrial radiations are natural types from radionuclides found in rocks, building materials and soils in an environment. Monitoring of background radiation energy levels in selected school in Ota, Ogun State Nigeria by direct measurement of terrestrial radiation dose rate was done. The mean dose rate ranged from 35.4 to 62.34 nGyh−1. The measured mean values are within world average recommended limits of 59 nGyh−1 except for study location SC7 with mean dose rate value of 62.34 nGyh−1. On the over all, it can be concluded that the concentration of NORM (naturally occurring radioactive materials) and radiation dose rate in an environment is at safe level. Further environmental radiation assessment is recommended to ascertain the possible sources of background radiation dose rate and exposure, beside terrestrial radiation sources.
A Mini Review on the Impact of Sewage Disposal on Environment and Ecosystem
Authors: Fayomi G U , Mini S E , Fayomi O S I , Owodolu T. , Ayoola A.A. , Wusu O.
Published: October 2019

Human activities contribute immensely to the production of wastewater which emanates from residences, industries and agricultural practices that pollutes the environment and water bodies. Up to 80-90% of the wastewater produced in developing countries is disposed of into surface and groundwater which is a major cause of environmental pollution that threatens human health. According to UN report, over 80% of the wastewater produced in the world and over 95% in some least developed countries is released without being treated into the environment. This paper reviews the methods of sewage disposal, the impact on the environment, aquatic contaminant and the human health. Emphasis is placed on the impact of disposal of various contaminants in aquifers and water bodies which could make water unsafe for drinking and to perform other domestic and recreational activities
Remediation of soil polluted with spent oil using cow dung
Authors: Nwinyi Obinna C , Akinmulewo B. A
Published: October 2019

Spent oil is any petroleum-based or synthetic oil that contain impurities or loss of major properties thus affecting its unique purpose. In this study, we selected and contaminated a site in Covenant University with spent oil. This site was amended with cow dung and studied for 56 days. Spent oil contaminated soil without stimulation with cow dung served as the control. This study was done during the dry season period and the sites left to natural edaphic factors. Physicochemical parameters such as pH, moisture content were monitored to determine the influence of cow dung as biostimulatory agent when compared with control (untreated) site. Within the period of this investigation, we recorded decrease in the pH value on the amended site, the value ranged between 8.60-7.77 while the control increased from 8.30 -8.42. The moisture content (%) were 95.0- 82.1 and 90.8-103.0 for the amended and control sites respectively. Following these obtained dynamics, we isolated organisms using enrichment technique from the contaminated sites and the control. We characterized the isolates using phenotypic characteristics and comparison with standard reference organisms. The bacterial isolates obtained include: Arthrobacter Mycobacteria Pseudomonas and Corynebacterium. The axenic cultures ability to utilize spent oil was monitored via indirect estimation using pH and Optical density dynamics for 240hrs. All the organisms exhibited growth in the MS medium supplemented with spent oil. The pH and optical density (OD) from bacterial species obtained from the control sample ranged between 6.91 ± 0.20- 6.56± 0.29 and the OD 0.278±0.150-0.826 ± 0.33. For the amended sample, the bacterial species showed decline in pH that ranged between 7.13±0.30 - 6.33±0.10 while the recorded OD values ranged between 0.190±0.03 - 0.621±0.50. Comparing the results obtained for the control and the amended soil. It was obvious that organisms from the amended soil (either in-situ or in-vivo) showed more metabolic activities on the spent oil. This study suggests that use of cow dung in appropriate concentrations could be very useful in bioremediation of soil contaminated with spent oil.
Effect of Saw-dust on soils contaminated with waste lubricating oil
Authors: Nwinyi Obinna C , Ikhine P. J
Published: October 2019

In this study, we evaluated the influence of sawdust as biostimulatory agent on waste-lubricating oil site. To achieve this, two sites were contaminated with waste lubricating oil, with one of the site amended with sawdust and the other left to serve as control. This study was conducted during the dry season. Decreases in pH and percentage moisture content were used to monitor the metabolic activities between the amended and control sites. Both sites (amended and control) showed decrease in the pH values however the control site showed just slight decrease. The mean pH value obtained ranged between 7.68± 0.15-8.08± 0.57 for the amended and control while the mean moisture content (%) 38.3 – 48.6 respectively for the amended and control sites. We screened for fungal species that showed growth on sawdust amended site using waste lubricating oil as source of carbon/energy. This was done through conventional enrichment culture methods. The isolated fungal strains tentatively named as P1, P2, P3, P4 and P5 were identified by visual observation and micro-morphological technique. From the cultural, and morphological characterization and comparison with respect to the standard reference of fungi, the fungal species were identified as members Aspergillus niger, Rhizopus sp., Pénicillium sp., Aspergillus flavus and Mucor sp. Pure cultures of these fungal species were tested for their ability to utilize waste lubricating oil as carbon and energy source. The ability of these fungal species to use the waste lubricating oil was done by monitoring their physiological responses via Optical Density (OD) and pH gradient readings. The mean pH obtained range from 5.90-7.33 and the (OD) 0.715-1.978. The fluctuations in OD readings as well as pH values for the different microfungi may be due to variation in growth patterns of the different fungal species.
Wine production from Hibiscus sabdariffa calyxes using probiotics starter cultures
Authors: Omole U. , Oranusi S.
Published: October 2019

Aqueous calyxes extract of Roselle, popularly known as Zobo drink in Nigeria is a non-alcoholic local beverage widely consumed by millions of people across different socio-economic classes. However, large-scale production of zobo is hindered by the rapid deterioration of the drink if not refrigerated. Thus the aim of this research was to extend the viability of the drink by fermentation into red wine using probiotic organism Lactobacillus fermentum and Saccharomyces cerevisiae. Both organisms produced wines of different physicochemical properties within 24hours fermentation and with pH 3.47 – 2.76, titratable acidity; 0.236%–0.252%; Vitamin C; 5.22 mg/100 – 2.44 mg/100 and total dissolvable solids; 11.95 Mg/L – 9.97 Mg/L for Lactobacillus fermentum and pH 3.48 – 2.8, titratable acidity; 0.2% – 0.225%, Vitamin C; 8.56mg/100 – 6.33mg/100 and total dissolvable solids; 13.32 Mg/L – 9.71 Mg/L for Saccharomyces cerevisiae. There was also a gradual alcohol increase during fermentation process and at the end, both wines showed alcohol content of 5.71% and 5.61% for Lactobacillus fermentum and Saccharomyces cerevisiae respectively. Except for the alcohol content, the results shows that the formulation with the brewers yeast produced a better wine at the 12 hour fermentation time. The sensory evaluation was also conducted using a 5 judge panel on a 7 point hedonic scale and the result shows that the wine produced from fermentation by Saccharomyces cerevisiae was moderately accepted (value 3) by the panel and the mean heterotrophic microbial load of 3±0.2 x 103 cfu/ml indicated that formulated red wine is safe for human consumption. The outcome of this study will boost the economy of this country if adopted for large scale production as it will generate revenue that would have been lost on importation of wine.
Air pollution Estimation Over Ponta
Authors: Emetere M.E. , Ahiara M.O.
Published: October 2019

The principal challenge of air pollution reportage in most communities of West Africa is the unavailability of working data. In this paper, satellite measurements were used to derive salient parameter (aerosol loading) to describe air quality over Ponta-Cape Verde was considered. Fifteen years primary (aerosol optical depth) dataset was obtained from the Multi-angle Imaging Spectro-Radiometer (MISR). The dataset is important to quantify the extent of air pollution in the research area. The statistical analysis of the dataset was also presented. It was observed that air pollution over Ponta is seasonal and comes from same source. Hence the pollution over is sustained due to a same pollution routine over the years.
Study of the lightning temporal and spatial characteristics based on CMA Lightning Detection Network in China
Authors: Li Feng , Li Yan , Wang Zhichao , Liang Li
Published: October 2019

Based on the lightning location data during 2009-2013 from China Meteorological Administration National-Lightning-Detection-Network (CMA LDN), this study analysed the temporal-spatial characteristics of the lightning in mainland China, and the results show: 1) Lightning detection systems used the Improved Performance through Combined Technology (IMPACT) method, which combined the direction finding (DF) and the time difference of arrival (TOA) technology. Among the four localization algorithms, the four-station method had the highest positioning accuracy, and its usage frequency also increased continuously, accounted for 50 %, up to 6000-10000 times by 2013. 2) Lightning activities showed clearly seasonal variation, and it had an increasing trend with a little inter-annual variation during the period of 2009 to 2013, which was mainly affected or restricted by ground temperature (rising from May every year, reaching its peak in August, and then gradually decreasing), potential water and convection in the atmosphere. 3) The negative cloud-to-ground (-CG) flashes were the absolute majority in China, positive cloud-to-ground (+CG) flashes accounted for 5.1 % of the total. Most of lightning currents ranged from -60 to +60kA. 4) The average lightning intensity of +CG and -CG flashes were 64.2kA and -40.28kA respectively. The positive lightning ratio is prominently high in December and January, most of which distributed in southern Anhui province, northern Jiangxi province, North Central Guangxi province, Yunnan province and West of Xinjiang Uygur Autonomous Region.
Analysis of subsidy strategy for sustainable development of environmental protection policy
Authors: Ko Chuan-Chuan , Liu Chien-Yu , Zhou Jing , Chen Zan-Yu
Published: October 2019

In the face of severe climate change and serious air pollution, governments should actively protect the environment and innovation to develop low-carbon energy, and formulate relevant carbon emission policies for enterprises to solve global warming problems. According to the social welfare point of view, this paper calls for the international must maintain global warming within the controllable range. Its core work is to effectively reduce carbon emissions. Under the assumption that the corporate profit target remains unchanged, when the government formulates a carbon reduction policy to levy a carbon emission tax for enterprises, enterprises should avoid the transfer of taxation costs to consumers; on the other hand, the government should formulate subsidy policies to encourage enterprises to actively cooperate. Carbon reduction, subsidized for the increased production costs of the company’s innovative technology to reduce carbon emissions. This paper uses the real options approach of dynamic decision-making, assuming that the subsidy rate of subsidy policy follows the geometric Brownian movement, constructs the government’s optimal subsidy policy model, and provides the government with a reference policy for subsidy policy, in order to create a realm of win-win situation for enterprises, government and social environment.
Sources and ecological assessment of heavy metal contamination in the surface sediment in Honghai Bay
Authors: Sun Qinbang , Liang Bin , Zhang Chong , Gao Fan , Chen Zhaolin
Published: October 2019

The sources and ecological environment of heavy metal contamination in the surface sediment of the Honghai Bay were studied, and the contents of seven heavy metals in sediment samples from 20 sampling stations were analysed. Principal Component Analysis (PCA) showed that the contribution rates of the first and second principal component was 60.41% and 16.48%, respectively. The study showed that the major sources of heavy metal contamination were industrial wastewater and municipal wastewater. Combined with the results of correlation analysis between heavy metals and TOC, it was found that Cu, Pb, Zn, Cr and As had a certain degree of homology. The contribution rate of each pollutant variable calculated by PCA method was used to determine the marine sediment pollution index (MSPI) to evaluate the contamination level of heavy metal, and the potential adverse effects of heavy metal contamination on the ecological environment were evaluated by the mean sediment guideline quotient (SQG-Q). The results showed that the sediment conditions were average (MSPI: 40.30-57.92), and the potential adverse biological effects had reached a moderate level (SQG-Q: 0.10-0.21). Heavy metal contamination level of the study area was moderate.
Impacts of environmental external driving forces on land-use changes of farm ponds in Taiwan
Authors: Yen Ke-Chin , Liu Yi-Hsuan
Published: October 2019

In Taiwan, the ponds which are mostly distributed on tablelands in the north areas are the special landscapes established for the water diversion and agricultural irrigation in the past. They provide beneficial functions to local environments and ecology under extreme climate. However, with the relocations of urban development centers, the urban expansions focusing on land developments leads the land-uses changes of ponds. Land uses are modes constructed by the interactions of manual activities and natural environmental factors, and the land-use changes are caused by the multiple interlacements of environmental external driving forces. Through the investigations of the external driving forces and the influence ways, the early analysis and to predictions of land-use changes will provide the references for environmental managements and plans. The contributions are more essential to Taoyuan areas with many ponds and rapid development especially. Based on the research achievements of coast environmental land-use changes, the research establishes the environmental external driving factor systems. Then it applies the DPSIR model to explore the land-use modes driving the changes of ponds, inducts the categories of land-use changes, and investigates the causality between them. Exploring how the ponds disappear and finding the factors will contribute to not only the environmental protection and ecological system maintenance, but also the adaption for climate change. The research results will provide the reference for land resource plans and developments by simulating the land-use changes of ponds.
Application of traditional water conservancy wisdom in the landscape of Suzhou Grand Canal
Authors: Xing Siqi , Ma Jianwu
Published: October 2019

China has a long history of shipping and an extremely rich cultural heritage of the Grand Canal, traditional water conservancy is an important part of it. As a section of the Beijing-Hangzhou Grand Canal, the Suzhou Grand Canal has a profound impact on the historical development of Suzhou. In the context of the revitalization and activation of the historical heritage of the Grand Canal, this paper follows the superior planning of the Suzhou High-tech Zone Planning Branch, takes the nodes along the Suzhou Grand Canal from Hengtang to Fengqiao as the base of creation to sort out the Suzhou Canal culture and traditional water conservancy’s technology. The purpose of this article is, from the perspective of the application of water conservancy facilities in the design of modern waterfront landscapes, to explore the possibility and reference of the combination of historical and cultural heritage rejuvenation with contemporary urban life, traditional wisdom reuse and contemporary landscape design.
High resolution OSL dating of the late quaternary loess from Central Shandong Mountains in eastern China and the paleoclimatic implications
Authors: Zhao Qiuyue , Ding Min , Peng Shuzhen , Zhang Wei , Song Bo , Zhou Rui , Yue Junsheng , Liang Mingying , Zhang Dongmei
Published: October 2019

The loess deposits widely distributed in the Central Shandong Mountains are significant terrestrial palaeoclimatic archives in the alluvial plain of eastern China. It is also sensitive records of East Asian monsoon changes for situating in a key region connected to the Eurasian plate and the Pacific Ocean. However, research into the climate changes in CSM loess is restricted by the lack of independent age control. High resolution samples of Optically Stimulated Luminescence (OSL) dating results are presented from a new Heishan loess section over ~34 ka. Our results reveal the following: (1) The boundary age defined by the sedimentation rates model between the Pleistocene and the Holocene at Heishan loess section is 10.9±0.6 ka. (2) A marked hiatus in the record is identified between ~30 and ~17 ka, probably resulting from deflation; this has never been raised in previous CSM loess researches and indicates that the study area is the wind erosion area during this time. (3) The relatively rapid sedimentation rate spanning 10.9±0.6 to 8.5±0.4 ka may be related to the post-depositional disturbance induced by more monsoon precipitation in the CSM region.
Research on dissolved organic matter degradation in biofilm reactor using the micro-bubbles
Authors: Chang Ming , Gao Chang , Hu Yanbin , Ji Meichen , Guo Dongheng
Published: October 2019

The performance of biofilm reactor using the micro-bubbles for dissolved organic matter (DOM) degradation was evaluated in this study. Synchronous fluorescence and UV absorption spectroscopy indicates that the small molecule substances was cleavaged in the reactor with ordinary bubbles, the degree of aromaticity increased during the reacting time and the removal efficiency of protein-like materials was ideal. Whereas in the reactor with microbubbles, the humic and protein-like materials both increased during the reaction time, suggesting that the reactor with microbubbles can improve the biochemical treatment of rural domestic sewage.
Numerical Investigation of a New Single Vortex Generation Technique
Authors: Hazel S , Huang Y , amirat M Ait
Published: October 2019

In this work a new single vortex generation method based on the flow past a rotating cylinder is proposed. Two dimensional numerical simulation for a laminar flow at Re = 100 is conducted to investigate this method. An impulsive drop of the rotation speed appeared to trigger a vortex roll up process; one single vortex is growing behind the cylinder and detached from it. The process is studied for different rotation drop rates and several final rotation rates. Vortex characteristics are computed and compared for different cases. Increasing rotation drop rate generates a more rapidly growing vortex. Its trajectory is closer to the geometric centreline and its size and intensity are higher. This new vortex generation method allows the investigation of new experimental configurations for studying vortex flame interaction.
A Discussion on Furniture Rental Service for Urban Migrants in China——From the Gain of a Lifestyle Design Research in Hong Kong & Beijing
Authors: Du Y
Published: October 2019

This article describes the results of a study on lifestyle design research in relation to the consumption of space & furniture of the urban migrants in China. The methodology adopted was based on online investigations of life patterns and residential situations of the straits and desires concerning with furniture and space. The results showed that Chinese urban migrants might be a suitable audience for renting furniture service, while the persona ‘Artistic Youth’ seems to be the most potential consumer group. The study found that an adequate service should be considered with Functional categories, Styles, Grade, Price and Accessory products, then a viable furniture rental model was initially conceived. The study also proposed the different emphases on furniture rental service between Hong Kong and Beijing: HK’s would focus on practical function and full use of space, BJ’s should pay more attention to whether it can improve the quality and taste of living.
Monotonicity of the Schwarz genus
Authors: Pavešić Petar
Published: October 2019

The Schwarz genus

g

(
ξ
)

\mathsf {g}(\xi )

of a fibration

ξ
:
E
→
B

\xi \colon E\to B

is defined as the minimal integer

n
n

such that there exists a cover of

B
B

by

n
n

open sets that admit partial sections to

ξ
\xi

. Many important concepts, including the Lusternik–Schnirelmann category, Farber’s topological complexity, and Smale–Vassiliev’s complexity of algorithms can be naturally expressed as Schwarz genera of suitably chosen fibrations. In this paper we study Schwarz genus in relation with certain types of morphisms between fibrations. Our main result is the following: if there exists a fibrewise map

f
:
E
→

E
′

f\colon E\to E’

between fibrations

ξ
:
E
→
B

\xi \colon E\to B

and

ξ
′

:

E
′

→
B

\xi ’\colon E’\to B

which induces an

n
n

-equivalence between respective fibres for a sufficiently big

n
n

, then

g

(
ξ
)
=

g

(

ξ
′

)

\mathsf {g}(\xi )=\mathsf {g}(\xi ’)

. From this we derive several interesting results relating the topological complexity of a space with the topological complexities of its skeleta and subspaces (and similarly for the category). For example, we show that if a CW-complex has high topological complexity (with respect to its dimension and connectivity), then the topological complexity of its skeleta is an increasing function of the dimension.
Decay estimates for higher-order elliptic operators
Authors: Feng Hongliang , Soffer Avy , Wu Zhao , Yao Xiaohua
Published: October 2019

This paper is mainly devoted to the study of time decay estimates of the higher-order Schrödinger-type operator

H
=
(
−
Δ

)

m

+
V
(
x
)

H=(-\Delta )^{m}+V(x)

in

R

n

\mathbf {R}^{n}

for

n
>
2
m

n>2m

and

m
∈

N

m\in \mathbf {N}

. For certain decay potentials

V
(
x
)

V(x)

, we first derive the asymptotic expansions of resolvent

R

V

(
z
)

R_{V}(z)

near zero threshold with the presence of zero resonance or zero eigenvalue, as well as identify the resonance space for each kind of zero resonance which displays different effects on time decay rate. Then we establish Kato-Jensen-type estimates and local decay estimates for higher-order Schrödinger propagator

e

−
i
t
H

e^{-itH}

in the presence of zero resonance or zero eigenvalue. As a consequence, the endpoint Strichartz estimate and

L

p

L^{p}

-decay estimates can also be obtained. Finally, by a virial argument, a criterion on the absence of positive embedding eigenvalues is given for

(
−
Δ

)

m

+
V
(
x
)

(-\Delta )^{m}+V(x)

with a repulsive potential.
An International Regime in an Age of Empire
Authors: Pedersen Susan
Published: October 2019

A century after the victorious Allied powers distributed their spoils of victory in 1919, the world still lives with the geopolitical consequences of the mandates system established by the League of Nations. The Covenant article authorizing the new imperial dispensation came cloaked in the old civilizationist discourse, entrusting sovereignty over “peoples not yet able to stand by themselves under the strenuous conditions of the modern world” to the “advanced nations” of Belgium, England, France, Japan, and South Africa. In this series of “reflections” on the mandates, ten scholars of Europe, Africa, the Middle East, Asia, and the international order consider the consequences of the new geopolitical order birthed by World War I. How did the reshuffling of imperial power in the immediate postwar period configure long-term struggles over minority rights, decolonization, and the shape of nation-states when the colonial era finally came to a close? How did the alleged beneficiaries—more often the victims—of this “sacred trust” grasp their own fates in a world that simultaneously promised and denied them the possibility of self-determination? From Palestine, to Namibia, to Kurdistan, and beyond, the legacies of the mandatory moment remain pressing questions today.
Contrasting phenotypes emerging from stable rules: A model based on self-regulated control loops captures the dynamics of shoot extension in contrasting maize phenotypes
Authors: Vidal T , Andrieu B
Published: October 2019

Background and Aims

The dynamics of plant architecture is a central aspect of plant and crop models. Most models assume that whole shoot development is orchestrated by the leaf appearance rate, which follows a thermal time schedule. However, leaf appearance actually results from leaf extension and taking it as an input hampers our ability to understand shoot construction. The objective of the present study was to assess a modelling framework for grasses, in which the emergence of leaves and other organs is explicitly calculated as a result of their extension.

Methods

The approach builds on a previous model, which uses a set of rules co-ordinating the timing of development within and between phytomers. We first assessed rule validity for four experimental datasets, including different cultivars, planting densities and environments, and accordingly revised the equations driving the extension of the upper leaves and of internodes. We then fitted model parameters for each dataset and evaluated the ability to simulate the measured phenotypes across time. Finally, we carried out a sensitivity analysis to identify the parameters that had the greatest impact and to investigate model behaviour.

Key Results

The modified version of the model simulated correctly the contrasting maize phenotypes. Co-ordination rules accounted for the observations in all studied cultivars. Factors with major impact on model output included extension rates, the time of tassel initiation and initial conditions. A large diversity of phenotypes could be simulated.

Conclusions

This work provides direct experimental evidence for co-ordination rules and illustrates the capacity of the model to represent contrasting phenotypes. These rules play an important role in patterning shoot architecture and some of them need to be assessed further, considering contrasting growth conditions. To make the model more predictive, several parameters could be considered in the future as internal variables driven by plant status.