bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Different Complex Fenestration Systems in Office Spaces in Chile: Analysis of the Energy Consumption and Visual Comfort of Occupants at the Early Stages of Their Design Process
Authors: Bustamante W , Molina G , Uribe D , Vera S
Published: June 2020

Office buildings around the world are mostly designed with high window-to-wall (WWR) facades, regardless of the type of climate where they are located. Chile, a country with a high climate diversity from north to south and from the coast to the Andes, is no exception to this situation. In order to improve the thermal and visual performance of office buildings, it has been shown that complex fenestration systems (SFC), which include an external solar protection system, are effective to control the incident solar radiation and lighting transmission. However, the effectiveness of these systems depends to a large extent on an appropriate CFS design. Some studies of office buildings in Chile show that a high percentage of CFS has not been designed correctly. To support the early stages of the design process of office buildings in Chile and to assist in the design of solar protection systems as part of a CFS, oficity, an easy-to-use tool was designed. In an office space and considering different facades of solar protection systems, the tool allows the development of simultaneous simulations of its total energy consumption (heating, cooling, and artificial lighting), together with the evaluation of the occupants’ visual comfort. The tool performs the simulations in just a few seconds, which makes it appropriate to support the preliminary stages of the building’s design process. The tool is compatible with PCs, smartphones, and tablets. The back end of oficity uses EnergyPlus for annual energy simulation and Radiance for annual lighting simulation. The use of these validated software makes the results of the simulations highly reliable. The tool considers 23 different climates of Chile. This research shows the analysis of an office space in different cities of the country, with variations in its orientation and the protection systems that are recommended for different climates.
Response and impact of fire on bird community in the tropical rainforest: a review
Authors: Mardiastuti Ani
Published: June 2020

Tropical rainforests are often catch by fires. Unfortunately, study on bird community and fire incident was lacking and strongly biased toward temperate forest. The objective of this paper was to provide a review on the response and impact of fire on bird communities inhabiting a tropical rainforest, through an intensive relevant literature review. Most birds are capable to escape fires through flying, although some nestlings, poor fliers and terrestrial birds might not. Thus, direct impacts of the smoke and flames are less significant compared to the indirect effects on habitat alteration. During fires, some birds might respond positively: raptors might circle over fires searching for small mammals exposed on the ground, while insectivorous birds might catch insects in a smoke column. After the fire, habitat was altered, food supply might change (decreased for most birds), while bird community composition might change due to the shift of the population of competitors or predators. Previous studies showed that effects of fire on bird community and their habitat varied widely. In Sumatra and Kalimantan, after fire insectivorous species increased, while the number of frugivorous and omnivorous birds were declined. When fires become too frequent and too intensive, however, vegetation will not able to recover and might lead to the situation where recovery of habitat and the bird community becomes impossible.
Estimation of bird species diversity recovery on post-burnt land in PT Waimusi Agroindah, South Sumatera
Authors: Putri Marini Machdi , Santosa Yanto
Published: June 2020

Currently, one of the events that are suspected to be the main cause of environmental damage is land fires, that are also a fairly routine event in Indonesia. One of the most highlighted fire issues is the fire in oil palm plantations. These fires have increased community assumptions regarding the impact of fires on ecosystems and biodiversity, including bird species diversity. The impact of the fire which was considered to have only a negative impact, led to various demands so that several palm oil industry companies were charged with paying recovery costs. There was a fire in 2015 at PT Waimusi Agroindah. The accusation that fires have only a negative impact requires further research to determine the potential recovery of bird species diversity on post-fire land, particularly in oil palm plantations. The method for estimating land restoration is to compare the diversity of bird species at 2 years after burning (2017) and 4 years after burning (2019). The observational method used was a line transect every morning and afternoon with three repetitions to inventory bird species diversity. The results showed as many as 40 species of birds found in the soil 4 years after burning, higher when compared to the land 2 years after burning found as many as 36 species of birds. This number is higher than the number of species found in unburned land by 25 species in 2017, and 36 species in 2019. The Margalef index equal to 6.11 in 2019 which increased 5.44 in 2017. Evenness index was 0.89 in in 2019 which was originally amounted to 0.83 in 2017. Overall there was a recovery in post-burnt land due to the gain of 12 species and a loss of 7 species. There are 2 species of gained bird included into protected species according to Permen LHK P N0.106 of 2018. An inncrease bird species diversity indicates the ability of the land to gradually recover.
Economic loss value from land and forest fires in oil palm plantation in Jambi, Indonesia
Authors: Putra Erianto Indra , Saharjo Bambang Hero , Wasis Basuki , Hero Yulius , Puspaningsih Nining
Published: June 2020

Peat fires have always become a problem for the country and result to enormous negative impact and losses to the environment and surrounding community. To clear the issues, we assess the economic valuation of peat fires in palm oil plantation in Tanjung Jabung Timur Regency, Jambi Province, Indonesia. Here, we focused on the economic losses from air pollution, environmental/ecological damage, and benefit loss of goods and services due to peat fire on 2002-2014. These economic losses are calculated based on Regulation of Minister of Environment No. 7/2014. We found the enormous total economic loss due to peat fire of more than IDR 4.46 trilion. Benefit loss of goods and services accounts for more than 50% of the total economic loss, followed by the loss from carbon emission. The area affected by the fire in the large scale-company owned palm oil plantation is found more than 29 times larger than the smallholder, but the impact/ha for the smallholder is more than twice of that in smallholder palm oil. These high lost due to peat fire on the oil palm plantation strongly suggest to escalate the fire prevention effort in the palm oil plantation to avoid further devastating peat fire and severe economic loss.
Influence of Multi-walled carbon nanotubes on mechanical properties of cement concrete
Authors: Kaur Mavjot , Murari Krishna , Singh Gurpuneet
Published: June 2020

The mechanical characteristic of cement concrete with incorporation of multi-walled carbon nanotubes (MWCNT) has been investigated in this paper. Disparate concrete mixes were prepared incorporating CNT-to-cement weight fractions of 0.075, 0.1, 0.125 wt.% in traditional concrete. The flexural and compressive strength were determined after 7 and 28 days of curing. The results of the experimental work showed the maximum increase in the strength was almost 1.5times than the conventional concrete which is believed to occur due to effective dispersion and nano-scale particle size. This was obtained in mix containing 0.075 wt.% of CNTs, making it the optimum content for improving strength parameters. Moreover, the post cracking strength of concrete after CNTs addition was found to be more than the conventional concrete with the reduction in the abrasion of the concrete.
Experimental investigation and effects of laser hardening process parameters on microhardness of En24 steel
Authors: Wagh Santoshkumar V. , Bhatt Dhananjay V. , Menghani Jyoti V. , Pardeshi Sujit S. , Deshmukh Bhagyesh B.
Published: June 2020

In presented paper through experimental investigation is carried out with fiber laser system so as to evaluate the effects of laser surface hardening process parameters on the microhardness (width and depth) of the laser treated En24 steel using a Taguchi method. The optical microscope and microhardness tester is used to examine the microstructure, microhardness (width and depth) of the laser hardened samples across the heat affected zone. The selected process parameters were laser beam power (210, 225 and 300 W), laser scanning speed (1.0, 5.5 and 10.0 mm/s) and standoff distance (175, 200 and 225 mm) respectively. The laser treated hardened surface layer has a microhardness of 728.1 HV0.3and reached a microhardness depth of 2471.44 µm, which is twice as high as untreated samples of En24 steel. From this study, it can be summarized that the microhardness of laser treated samples is maximized by controlling laser beam power, laser scanning speed and standoff distance, which improves the service life of laser-treated En24 steel components. The percentage error within the acceptable range was found to be small and was obtained by comparing the microhardness values obtained from the experimental results and predicted microhardness values obtained by using nonlinear regression equation.
Static buckling analysis of shape memory alloy reinforced composite laminated plate
Authors: Lal Achchhe , Markad Kanif
Published: June 2020

With high strength and stiffness composites are being widely used as structural materials. The properties of composites can further improve by reinforcing with advanced structural components like shape memory alloys (SMA). In the present study nonlinear buckling analysis of laminated composite plate with layer of shape memory alloys are done. Finite element governing equation based higher order shear deformation theory with principle of virtual work is considered. Properties of composite plates are formulated with micro-mechanical approach. A MATLAB program is developed with nine nodes isoperimetric element. Influence of volume fraction of SMA, recovery stress, with and without SMA layer, with temperature on critical buckling load is revealed. Convergence and validation study presented here shows the exactness and efficiency of the model.
Stress analysis of composite plate with cutout of various shape
Authors: Lal Achchhe , Sutaria B.M , Kumar Rahul
Published: June 2020

Composite plate found numerous applications in various structures due to its superior properties like high stiffness to weight and strength to weight ratio. Generally, cutouts in these structural elements are unavoidable for many purposes like access to internal parts, ventilation and sometimes to prevent resonance. These geometrical discontinuities in the form of cutouts may be of different shapes and arise nonuniform stress in the plate. Therefore, it becomes necessary to analyse stress concentration factor near cutouts and effect of shape of cutouts on axial deformation and stress distribution for better safety and stability of structure. In the present investigation a Carbon/epoxy composite plate with various shape of cutout subjected to in-plane tensile loading is considered. Finite element based plane stress analysis is used for mathematical modeling. A program for the present analysis is developed in MATLAB. Variation of in-plane displacement and stress concentration factor (SCF) with various shape of cutout is determined. The effect of the geometry of hole on the stress distribution around the hole is also studied. The results of various analyses have been presented with the help of tables, graphs, and nodal plots.
Analysis, modeling and optimization of surface roughness in cylindrical traverse cut grinding using factorial design, RSM and simulated annealing algorithm
Authors: Rudrapati R , Bandyopadhyay A , Pal P K , Rathod L
Published: June 2020

In the present investigation, a new hybrid technique response surface methodology (RSM) based simulated annealing (SA) algorithm approach is proposed to predict surface roughness for stainless steel material in traverse cut cylindrical grinding process. Experiments are designed as per full factorial design, wherein infeed, longitudinal feed and work speed have been considered as the important input parameters. Analysis of variance and graphical main and interaction plots have been plotted for analyzing the experimental data for identifying the relationships between grinding parameters and surface roughness. The variation of the performance parameter (surface roughness) with grinding parameters has been mathematically modeled by RSM. SA algorithm has been employed for solving the obtained mathematical model. Finally, the validation exercise is performed with optimum levels of grinding parameters. The results confirm the efficiency of the approach employed for prediction of surface roughness in this study.
Numerical study of edge crack interaction with inclusion and void of an isotropic plate under different loadings by extended finite element method
Authors: Lal Achchhe , Vaghela Manoj B. , Mishra Kundan
Published: June 2020

In the present work Extended Finite Element Method (XFEM) is utilized for interaction study of cracked isotropic plate under different loading conditions. XFEM is a powerful tool to handle fracture mechanics problems where, extra enrichment functions for the crack faces and tip are get utilized. In this present work main focus is interaction study of edge cracked isotropic plate with inclusion and void under tensile, shear, combined (tensile and shear) and exponential loading. Here, MATLAB environment is used to evaluate mixed mode stress intensity factor (MMSIF) of edge cracked isotropic plate when interacted with inclusion and void.
Computational analysis of novel cavity-based flameholder designs for supersonic combustion engines
Authors: Nayal Sanchayata , Lamb Sampada , Sahoo Devabrata , Raghavendra N. V. , Bellary S.A.I.
Published: June 2020

Computational analysis for novel cavity-based flameholder designs with different fore-wall and aft-wall inclinations has been presented. The flameholder performance has been evaluated based on the following key parameters: pressure distribution, temperature distribution, recirculation zones and drag force. On comparing the different cavity designs, it has been found that both the fore-wall and aft-wall angles affect the flameholder performance. It was observed that an obtuse fore-wall angle gave favourable results numerically. Further studies can analyze cavities with different obtuse fore-wall ramp angles for optimum flameholder performance.
Probabilistic design of composite leaf spring by using finite element method
Authors: Khiste S G , Kulkarni P , Katekar S D
Published: June 2020

A parametric model is created in ANSYS workbench, FEA method is used to carry out probabilistic design in ANSYS workbench. Mono leaf spring is considered for analysis purpose and analysis is carried out. Composite material is applied to parametric model. Boundary conditions are applied to mono leaf spring, both ends are fixed and load (force) is applied to mono leaf spring. Meshing is carried out. The geometric parameters (thickness, width, etc.) are used as input parameter and Von-Mises stress considered as output parameter. For any further uncertainty in analysis, parametric co-relation function is used in ANSYS. The relation in geometric parameter and output parameter is achieved by correlation coefficients
Seismic Assessment of Concrete Column Reinforced with Fiber Reinforced Polymer and Stainless Steel Rebars
Authors: Thakur Bhairav , Pardeshi Rahul , Patel Mayank , Parghi Anant
Published: June 2020

The fiber reinforced polymer (FRP) rebar is utilized as a corrosion resistive reinforcement in the structural elements like a beam, column, and slab. The FRP rebar offers excellent mechanical and durability properties, like high strength to weight ratio, high stiffness, and corrosion resistance to structures. However, a lower ductility subjected to linear-elastic behaviour, and the brittle nature of FRP particularly in the case of column applications is getting attention among researchers. Whereas stainless steel (SS) having adequate ductility, low maintenance, and resistance to corrosion make it an ideal material for reinforcing applications. To improve the performance of FRP-reinforced elements and diminish the brittle behaviour, the present research is focused on the utilization of SS rebar in the plastic hinge region of the column along with FRP rebar in rest portion of a column. This hybrid configuration is adopted here to improve the ductility and corrosion resistance capacity of the RC column. The damage concentration of the hybrid column is analysed under the effect of nonlinear static loads. The parametric analysis is performed over the hybrid column to study the behaviour of different factors under pushover loading. The results indicate that the ductility of the SS-FRP RC column is achieved under seismic loads. The study reveals that axial load, the yield strength of steel and aspect ratio significantly affect the behaviour of the SS-FRP RC column.
Stabilization on Expansive soil using sea shell powder and Rubber powder
Authors: Vinod B R , Shobha R , Raghavendra A B , Rakesh M , Pallavi S
Published: June 2020

BCS, type of expansive soil which is responsible for the volumetric changes with the change in the moisture content due to the excessive presence of montmorillonite. The stabilization of soil is the process of enhancing the properties of expensive soil and makes it stable to withstand the load acting on it. The stabilization is done by controlled compaction and addition of different types of stabilizers and admixtures. Hence this stabilization is done by various admixtures like cement, fly ash, bagasse, coir fibre, granite dust, rubber powder, sea shell powder etc. this paper represents the study of rubber powder and sea shell powder as different admixture to refine BCS properties. The unconfined compressive strength of BCS is found by adding sea shell powder and rubber powder as admixture, here this paper presents the results of an attempts that are performed.
Life cycle assessment modelling for a developing city‘s water system
Authors: Shrivastava Pooja , Verma M.K. , Murmu Meena , Ahmad Ishtiyaq
Published: June 2020

The research objective to analysis the urban water system (UWS) includes water treatment and distribution, wastewater collection, treatment, and disposal for Raipur city of Chhattisgarh state in India. The city has a dry tropical climate and a warm summer. Developing city is being under pressure due to rapid population expansion, urbanization and industrialization that causes a considerable change in water resources and their services Using SIMA-PRO LCA technology with ReCiPe and IPCC methods, the environmental impact assessment for the urban water system in Raipur was calculate by conducting a life cycle assessment (LCA). LCA tool focuses on water treatment and supply, wastewater, storm water, energy consumption, emission of pollutants and heavy elements to the water bodies and to sewage sludge and others spatial considerations such as population, economic and social assessment, water quality along with stakeholder engagement. LCA is a useful tool for identifying alternative environmental impact solutions and urban water operation scenarios for future strategic planning. In assessment, we found that water losses in distribution network and electricity consumption in water treatment have highest impact on environment while reducing this two by 15% and 2% then it reduces impact about 16%. We studied the existing conditions and different scenarios in this research to enhance the system’s environmental quality and to find solutions to improve sustainability.
Review on Passive Heat Enhancement Techniques in Pool Boiling Heat Transfer
Authors: Katarkar Anil , Majumder Biswajit , Bhaumik Swapan
Published: June 2020

Improvement of pool boiling heat transfer is deeply connected to heat enhancement methods for several years. Nevertheless, the developing progress and ideas in this field make it more intensified with the recently applied methods for enhancing the CHF and HTC. This paper gives a critical analysis and thorough investigative study in the literature discussing the passive heat enhancement techniques in the pool boiling heat transfer. Heat improvement consequence within the pool boiling mainly depends on thermo-physical features of material & the working fluid, modification of surface techniques (pin-fins treated, roughness, extended, artificial cavities pattern, micro-channels), thin-film (nano-scale, micro-scale, macro-scale surfaces, and hybrid scale), coating method, working fluid (water or refrigerants) and additives for fluids. The current status of these passive heat enhancement methods for pool boiling heat transfer with various kinds, improvement potentials, future challenges, surface modification techniques, and their potential industrial and technical applications are also examined in this work.
The nonlinear deflection response of CNT/nanoclay reinforced polymer hybrid composite plate under different loading conditions
Authors: Lal Achchhe , Kanu Nand Jee
Published: June 2020

The carbon nanotubes (CNTs) are used as significant reinforcement materials in the advanced composites due to their improved mechanical properties. The carbon nanotubes reinforced nanocomposites have improved mechanical strength, and stiffness properties in addition to their reduced weight. Only a few percentages of CNTs (2–5% by weight) could be added to these nanocomposites as more volume fraction will deteriorate their mechanical properties. A computational approach is used in the present investigation to find the mechanical properties of the hybrid nanocomposite which is modeled by adding nanoclay particles into the conventional CNTs reinforced epoxy system. Using Halpin-Tsai approach (which is based on the micromechanical modeling) the mechanical properties of hybrid nanocomposites are evaluated. The effect of the CNTs and the nanoclay particles on the nonlinear transverse central deflection response of nanocomposite plate under different loading conditions is studied in detail. The simulation results of present investigation have been validated with the data sets of the deflection responses available in the references.
Optical and Gas sensing properties of BaxSr1-xTiO3 (with x=0.5 and x=0.7) thin films grown using Pulse Laser Deposition
Authors: Shastri Nipa M. , Raval Adhish V. , Joshi V.G.
Published: June 2020

Thin films of Barium Strontium Titanate (BST) have been fabricated using Pulse Laser Deposition (PLD) technique. Two stoichiometries of BaxSr1-xTiO3 with x=0.5 and x=0.7 are deposited on well cleaned quarts substrates in high vacuum chamber with oxygen pressure of 0.13mbar at 700˚C. XRD pattern shows perovskite structure of the films. Energy Dispersive X-ray (EDX) is used to determine the element concentration of both the films. Transmittance spectra of UV characterization shows decrement in transparency of the film as Barium (Ba) concentration increase and sharp cut-offs are observed at the band edge. Refractive Index (n), absorption coefficient (α), extinction coefficient (k), optical conductivity (σ) and optical band gap (Eg) are derived from UV-Vis spectroscopy. The calculated parameters for Ba0.5Sr0.5TiO3 and Ba0.7Sr0.3TiO3 are presented in this work. The present work also includes study of BST thin films as gas sensors.
Study on Effect of Abrasive Water Jet Machining Process Parameter on Taper Angle during Machining of Epoxy Resin Glass Fibre
Authors: Gawade Meghna K , Jatti Vijaykumar S , Phule Vaibhav V , Sawant Pranita V
Published: June 2020

Abrasive Water Jet Machining (AWJM) is one of the most advanced machining processes, which has the ability to machine various materials. In this paper, experiment was performed on cutting of epoxy fibre glass by AWJM. Epoxy fibre glass is a composite which consists of fibre glass cloth and epoxy resin as binder, achieved under specific heat and pressure. There are various process parameters such as water pressure, standoff distance, abrasive flow rate, traverse rate, abrasive etc. The water pressure and standoff distance was varied while performing the experiment and rest all parameters were kept constant. From this experiment taper angle was measured and it was observed that taper angle increases as the standoff distance increases, this is because the shape of the jet diverges with larger standoff distance. Minimum taper angle was observed as 0.34° at 32 ksi pressure, having 2 mm standoff distance. It was also observed that width of cut has significant effect on taper angle. From further calculations, the deviation of the cut slot for top width was observed as +1% to 5% and for bottom width it was -1% to 2%.
Blast resistance of steel plate shear walls designed for seismic loading
Authors: Sunagar Prashant , Bhashyam Aravind , Dharek Manish S , Sreekeshava K S , Ramegowda R S , Lakshmi H S
Published: June 2020

Since a blast loading or explosion can create nonlinear wave action and impact pressure on a structure, it necessary to construct a structure to resist blast loading as like other loads. In this study the nonlinear behaviour of a blast loading is simulated by calculating the pressure diagram with respect to time under the guidance of IS 4991 – 1968, code for “Criteria for Blast Resistant Design of Structures for Explosions above Ground”. The study carried out for different charge weight (100kg TNT, 200kg TNT and 400kg TNT) and standoff distances of 20metre. Nonlinear behaviour of a Blast loading to steel structures with shear plates of thickness 6 mm, 8 mm and 10 mm are modelled in ETABS and the analysis is carried out to obtain base shear, story displacement, story deformation pattern, column forces, etc.
Spatial variation of climate change issues using remote sensing technique
Authors: Rao Kumar R , Sreekeshava K S , Dharek Manish S , Sunagar Prashant C , Ganesh C R
Published: June 2020

The assessment of climate change can be carried out by analysing rainfall variability, temporal climatic changes, spatial interpolation of climatic factors and climatic risking. The climatic changes have consequences on precipitation pattern changes, temperature variation, and crop growing season alteration, increase of sea ice and grounded ice sheets. This has implications on ecosystem, human health, settlement and agriculture. Some of the repercussions attributed to temperature and precipitation increase is an increase of Cyclonic activities with increase of cyclonic wind speeds, Increase in Extreme Precipitation events like floods and droughts, agricultural yield is projected to decrease and negative impact on subsistence agriculture. The Tropical Cyclones intensifying in eastern Indian Ocean and crossing the coasts of Indian subcontinent year after year is a major cause of concern. The Latent Heat Release (LHR) of cyclones of Bay of Bengal carried out using advanced sensors like SSM/I (Special Sensor Microwave/Imager) on-board DMSP satellites (Defence Meteorological Satellite Program of US) for assessing spatial distribution of precipitation since LHR is responsible for maintenance and intensification of tropical cyclones and LHR can also enable measurement of brightness temperatures of atmospheric/ocean surfaces. The images of the clouds in visible and infrared region provide information about cloud aerial extent, type, and growth/decay. The raining clouds have high visible band reflectance and are tall due to upward motion indicating deep convection. These issues pertaining to climate changes through Remote sensing techniques is discussed in the paper.
In vitro evaluation of antimicrobial activity of chlorhexidine hexametaphosphate nanoparticle coatings on orthodontic elastomeric chains
Authors: Subramani Karthikeyan , Seo Han Na , Dougherty Joseph , Chaudhry Kishore , Bollu Prashanti , Rosenthal Kenneth S , Zhang Jian Feng
Published: June 2020

This study was conducted to evaluate antimicrobial activity of orthodontic elastomeric chains (OECs) coated with chlorhexidine (CHX) hexametaphosphate (HMP) nanoparticles and its effect on force decay. OECs were coated with CHX-HMP-5 (5 mM CHX and HMP), CHX-HMP-1 (1 mM CHX and HMP) nanoparticle colloidal solutions, CHX-5 (5 mM CHX) and CHX-1 (1 mM CHX) solutions. Release of CHX from coated OECs was evaluated over 28 days. Antimicrobial activity of the eluate collected on day 1 was tested against Streptococcus mutans and Lactobacillus rhamnosus by measuring the zone of inhibition after 4 days. OECs were observed by scanning electron microscope (SEM) to observe surface characteristics comparing: (1) uncoated and coated OECs and (2) before and after release of CHX. Force decay of OECs were measured over 28 days. SEM analysis showed that OECs were coated with nanoparticles. OECs coated with CHX-HMP-5 and CHX-HMP-1 released CHX over 28 days. The eluate from the coated OECs produced zones of inhibition after day 4 towards S. mutans and L. rhamnosus. Both CHX-HMP nanoparticle coated OEC released CHX over a period of 28 days that was capable of inhibiting the growth of S. mutans and L. rhamnosus. For all groups, the largest mean loss of force occurred over the first 24 h, followed by a relative plateau. All groups maintained >50% of the initial mean force over entire experiment of 28 days. This study showed that OECs can be coated with CXH-HMP nanoparticles that continuously elute the antimicrobial for extended periods. The coatings did not alter the force decay of OECs. Use of such coating on OECs can provide antibacterial activity to aid in the reduction of biofilm buildup and prevention of white spot lesions. This approach offers promising clinical applications.
Characterization of oscillation amplitude of contact angle during AC electrowetting of water droplets
Authors: Wikramanayake Enakshi , Bahadur Vaibhav
Published: June 2020

Most studies on electrowetting (EW) involve the use of AC electric fields, which cause droplets to oscillate in response to the sinusoidal waveform. Oscillation-driven mixing in droplets is the basis for multiple microfluidic applications. Presently, we study the voltage and AC frequency-dependent oscillations of electrowetted water droplets on a smooth, hydrophobic surface. We introduce a new approach towards analyzing droplet oscillations, which involves characterization of the oscillation amplitude of the contact angle (CA). An experimentally validated, fundamentals-based model to predict voltage and frequency-dependent CA oscillations is developed, which is analogous to the Lippmann’s equation for predicting voltage-dependent CAs. It is seen that this approach can help estimate the threshold voltage more accurately, than from experimental measurements of CA change. Additionally, we use a coplanar electrode configuration with high voltage and ground electrodes arranged on the substrate. This configuration eliminates measurement artefacts in the classical EW configuration associated with a wire electrode protruding into the droplet. An interesting consequence of this configuration is that the system capacitance is reduced substantially, compared to the classical configuration. The coplanar electrode configuration shows a reduced rate of CA change with voltage, thereby increasing the voltage range over which the CA can be modulated.
Hölder stability in determining elastic coefficients of Biot's system in poroelastic media
Authors: Zhang Wensheng , Jiang Zifan
Published: June 2020

In this paper, we investigate an inverse problem of determining the four spatially varying elastic coefficients of Biot’s system simultaneously, i.e., the two Lamé parameters, the dilatational coupling factor and the bulk modulus, by a single measurement of data on a neighbourhood of the boundary. Following the idea of the B-K method, we prove the Hölder stability estimate of this inverse problem based on Carleman estimates.
DeepAntigen: a novel method for neoantigen prioritization via 3D genome and deep sparse learning
Authors: Shi Yi , Guo Zehua , Su Xianbin , Meng Luming , Zhang Mingxuan , Sun Jing , Wu Chao , Zheng Minhua , Shang Xueyin , Zou Xin , Cheng Wangqiu , Yu Yaoliang , Cai Yujia , Zhang Chaoyi , Cai Weidong , Da Lin-Tai , He Guang , Han Ze-Guang
Published: June 2020

Motivation

The mutations of cancers can encode the seeds of their own destruction, in the form of T-cell recognizable immunogenic peptides, also known as neoantigens. It is computationally challenging, however, to accurately prioritize the potential neoantigen candidates according to their ability of activating the T-cell immunoresponse, especially when the somatic mutations are abundant. Although a few neoantigen prioritization methods have been proposed to address this issue, advanced machine learning model that is specifically designed to tackle this problem is still lacking. Moreover, none of the existing methods considers the original DNA loci of the neoantigens in the perspective of 3D genome which may provide key information for inferring neoantigens’ immunogenicity.

Results

In this study, we discovered that DNA loci of the immunopositive and immunonegative MHC-I neoantigens have distinct spatial distribution patterns across the genome. We therefore used the 3D genome information along with an ensemble pMHC-I coding strategy, and developed a group feature selection-based deep sparse neural network model (DNN-GFS) that is optimized for neoantigen prioritization. DNN-GFS demonstrated increased neoantigen prioritization power comparing to existing sequence-based approaches. We also developed a webserver named deepAntigen (http://yishi.sjtu.edu.cn/deepAntigen) that implements the DNN-GFS as well as other machine learning methods. We believe that this work provides a new perspective toward more accurate neoantigen prediction which eventually contribute to personalized cancer immunotherapy.

Availability and implementation

Data and implementation are available on webserver: http://yishi.sjtu.edu.cn/deepAntigen.

Supplementary information

Supplementary data are available at Bioinformatics online.
In search of lost mixing time: adaptive Markov chain Monte Carlo schemes for Bayesian variable selection with very largep
Authors: Griffin J E , Łatuszyński K G , Steel M F J
Published: June 2020

The availability of datasets with large numbers of variables is rapidly increasing. The effective application of Bayesian variable selection methods for regression with these datasets has proved difficult since available Markov chain Monte Carlo methods do not perform well in typical problem sizes of interest. We propose new adaptive Markov chain Monte Carlo algorithms to address this shortcoming. The adaptive design of these algorithms exploits the observation that in large-$p$, small-$n$ settings, the majority of the $p$ variables will be approximately uncorrelated a posteriori. The algorithms adaptively build suitable nonlocal proposals that result in moves with squared jumping distance significantly larger than standard methods. Their performance is studied empirically in high-dimensional problems and speed-ups of up to four orders of magnitude are observed.
“Treat them as a human being”: dignity in police detention and its implications for ‘good’ police custody
Authors: Skinns Layla , Sorsby Angela , Rice Lindsey
Published: June 2020

Here, we examine the factors influencing whether those detained by the police feel treated with dignity. We develop a human rights-oriented conception of dignity rooted in the equal worth of human beings, encapsulated in detainees’ desire to be ‘treated like a human being’. The predictors of this are examined using multilevel modelling of survey data collected from 371 detainees in 27 custody facilities in 13 police forces in England and Wales in an Economic and Social Research Council-funded study of ‘good’ police custody. We found that perceptions of the material conditions predicted feelings of dignity, as did detainees’ reactions to being detained, their perceptions of the culture of police custody and the mechanisms used to hold the police to account. Feelings of dignity were also less likely for younger adults and for Black Asian and Minority Ethnic detainees, with these experiences being mediated by less trust in accountability mechanisms. This paper concludes by examining the implications for ‘good’ police custody.
The synstigma turns the fig into a large flower
Authors: Teixeira Simone P , Costa Marina F B , Basso-Alves João Paulo , Kjellberg Finn , Pereira Rodrigo A S
Published: June 2020

The synstigma is a structure formed by clusters of two to several stigmas, whether in the same or between different flowers. Although rare in angiosperms, synstigmas are found in c. 500 out of the c. 750 Ficus spp. (Moraceae). This floral structure is associated with fig-fig wasp pollinating mutualism. The synstigma structure and pollen tube pathways were studied in six Ficus spp. from Ficus section Americanae to test the hypothesis that the synstigma allows pollen grains deposited on a stigma to emit pollen tubes that can grow laterally and fertilize surrounding flowers. Syconia containing recently pollinated stigmas were collected and dissected, and the stigmas were processed for analyses with light and scanning and transmission electron microscopy. The arrangement of the synstigmas across species can be spaced or congested, with the number of stigmas per synstigma ranging from two to 20. Contact between the stigmas in a synstigma occurs by the intertwining of the stigmatic branches and papillae; their union is firm or loose. The pollen tube grows through live cells of the transmitting tissue until reaching the ovule micropyle. Curved pollen tubes growing from one stigma to another were observed in five out of the six species studied. The curvilinear morphology of pollen tubes probably results from competition by pollen between the stigmas composing a synstigma via chemotropic signals. The synstigma appears to be a key adaptation that ensures seed production by flowers not exploited by the fig wasps in actively pollinated Ficus spp.
A clinical-radiological framework of the right temporal variant of frontotemporal dementia
Authors: Ulugut Erkoyun Hulya , Groot Colin , Heilbron Ronja , Nelissen Anne , van Rossum Jonathan , Jutten Roos , Koene Ted , van der Flier Wiesje M , Wattjes Mike P , Scheltens Philip , Ossenkoppele Rik , Barkhof Frederik , Pijnenburg Yolande
Published: June 2020

The concept of the right temporal variant of frontotemporal dementia (rtvFTD) is still equivocal. The syndrome accompanying predominant right anterior temporal atrophy has previously been described as memory loss, prosopagnosia, getting lost and behavioural changes. Accurate detection is challenging, as the clinical syndrome might be confused with either behavioural variant FTD (bvFTD) or Alzheimer’s disease. Furthermore, based on neuroimaging features, the syndrome has been considered a right-sided variant of semantic variant primary progressive aphasia (svPPA). Therefore, we aimed to demarcate the clinical and neuropsychological characteristics of rtvFTD versus svPPA, bvFTD and Alzheimer’s disease. Moreover, we aimed to compare its neuroimaging profile against svPPA, which is associated with predominant left anterior temporal atrophy. Of 619 subjects with a clinical diagnosis of frontotemporal dementia or primary progressive aphasia, we included 70 subjects with a negative amyloid status in whom predominant right temporal lobar atrophy was identified based on blinded visual assessment of their initial brain MRI scans. Clinical symptoms were assessed retrospectively and compared with age- and sex-matched patients with svPPA (n = 70), bvFTD (n = 70) and Alzheimer’s disease (n = 70). Prosopagnosia, episodic memory impairment and behavioural changes such as disinhibition, apathy, compulsiveness and loss of empathy were the most common initial symptoms, whereas during the disease course, patients developed language problems such as word-finding difficulties and anomia. Distinctive symptoms of rtvFTD compared to the other groups included depression, somatic complaints, and motor/mental slowness. Aside from right temporal atrophy, the imaging pattern showed volume loss of the right ventral frontal area and the left temporal lobe, which represented a close mirror image of svPPA. Atrophy of the bilateral temporal poles and the fusiform gyrus were associated with prosopagnosia in rtvFTD. Our results highlight that rtvFTD has a unique clinical presentation. Since current diagnostic criteria do not cover specific symptoms of the rtvFTD, we propose a diagnostic tree to be used to define diagnostic criteria and call for an international validation.
Neuronal Network Topology Indicates Distinct Recovery Processes after Stroke
Authors: Latifi Shahrzad , Mitchell Simon , Habibey Rouhollah , Hosseini Fouzhan , Donzis Elissa , Estrada-Sánchez Ana María , Nejad H Rezaei , Levine Michael , Golshani Peyman , Carmichael S Thomas
Published: June 2020

Despite substantial recent progress in network neuroscience, the impact of stroke on the distinct features of reorganizing neuronal networks during recovery has not been defined. Using a functional connections-based approach through 2-photon in vivo calcium imaging at the level of single neurons, we demonstrate for the first time the functional connectivity maps during motion and nonmotion states, connection length distribution in functional connectome maps and a pattern of high clustering in motor and premotor cortical networks that is disturbed in stroke and reconstitutes partially in recovery. Stroke disrupts the network topology of connected inhibitory and excitatory neurons with distinct patterns in these 2 cell types and in different cortical areas. These data indicate that premotor cortex displays a distinguished neuron-specific recovery profile after stroke.
Sensitivity of Nasopharyngeal Swabs and Saliva for the Detection of Severe Acute Respiratory Syndrome Coronavirus 2
Authors: Jamal Alainna J , Mozafarihashjin Mohammad , Coomes Eric , Powis Jeff , Li Angel X , Paterson Aimee , Anceva-Sami Sofia , Barati Shiva , Crowl Gloria , Faheem Amna , Farooqi Lubna , Khan Saman , Prost Karren , Poutanen Susan , Taylor Maureen , Yip Lily , Zhong Xi Zoe , McGeer Allison J , Mubareka Samira ,   Toronto Invasive Bacterial Diseases Network COVID-19 Investigators, Coleman Brenda L , Chen Danny , Farshait Nataly , Gold Wayne , Kandel Christopher E , Katz Kevin , Kozak Robert , Mazzulli Tony , Muller Matthew , Opavsky Anne , Ostrowski Mario , Plevneshi Agron , Rau Neil , Ricciuto Daniel , Richardson David , Rose David , Sales Valerie , Walmsley Sharon
Published: June 2020

We enrolled 91 consecutive inpatients with COVID-19 at 6 hospitals in Toronto, Canada, and tested 1 nasopharyngeal swab/saliva sample pair from each patient using real-time RT-PCR for severe acute respiratory syndrome coronavirus 2. Sensitivity was 89% for nasopharyngeal swabs and 72% for saliva (P = .02). Difference in sensitivity was greatest for sample pairs collected later in illness.
Model-based Cost-effectiveness of State-level Latent Tuberculosis Interventions in California, Florida, New York, and Texas
Authors: Jo Youngji , Shrestha Sourya , Gomes Isabella , Marks Suzanne , Hill Andrew , Asay Garrett , Dowdy David
Published: June 2020

Background

Targeted testing and treatment (TTT) for latent tuberculosis (TB) infection (LTBI) is a recommended strategy to accelerate TB reductions and further TB elimination in the United States. Evidence on cost-effectiveness of TTT for key populations can help advance this goal.

Methods

We used a model of TB transmission to estimate the numbers of individuals who could be tested by interferon-γ release assay and treated for LTBI with 3 months of self-administered rifapentine and isoniazid (3HP) under various TTT scenarios. Specifically, we considered rapidly scaling up TTT among people who are non–US-born, diabetic, living with human immunodeficiency virus (HIV), homeless or incarcerated in California, Florida, New York, and Texas—states where more than half of US TB cases occur. We projected costs (from the healthcare system perspective, in 2018 dollars), 30-year reductions in TB incidence, and incremental cost-effectiveness (cost per quality-adjusted life-year [QALY] gained) for TTT in each modeled population.

Results

The projected cost-effectiveness of TTT differed substantially by state and population, while the health impact (number of TB cases averted) was consistently greatest among non–US-born individuals. TTT was most cost-effective among persons with HIV (from $2828/QALY gained in Florida to $11 265/QALY gained in New York) and least cost-effective among people with diabetes (from $223 041/QALY gained in California to $817 753/QALY in New York).

Conclusions

The modeled cost-effectiveness of TTT for LTBI varies across states but was consistently greatest among people with HIV; moderate among people who are non–US-born, incarcerated, or homeless; and least cost-effective among people with diabetes.
Safety and Efficacy of 48 and 96 Weeks of Alendronate in Children and Adolescents With Perinatal Human Immunodeficiency Virus Infection and Low Bone Mineral Density for Age
Authors: Lindsey Jane C , Jacobson Denise L , Spiegel Hans M , Gordon Catherine M , Hazra Rohan , Siberry George K
Published: June 2020

No safety concerns were identified in a randomized, crossover study of alendronate/placebo in youth with perinatal HIV infection and low bone mineral density (BMD). BMD improved with 48 weeks of alendronate and continued to improve with an additional 48 weeks of therapy. Gains were largely maintained 48 weeks after stopping alendronate.
Xpert My
cobacterium tuberculosis/Rifampicin–Detected Rifampicin Resistance is a Suboptimal Surrogate for Multidrug-resistant Tuberculosis in Eastern Democratic Republic of the Congo: Diagnostic and Clinical Implications
Authors: Bisimwa Bertin C , Nachega Jean B , Warren Robin M , Theron Grant , Metcalfe John Z , Shah Maunank , Diacon Andreas H , Sam-Agudu Nadia A , Yotebieng Marcel , Bulabula André N H , Katoto Patrick D M C , Chirambiza Jean-Paul , Nyota Rosette , Birembano Freddy M , Musafiri Eric M , Byadunia Sifa , Bahizire Esto , Kaswa Michel K , Callens Steven , Kashongwe Zacharie M
Published: June 2020

Background

Rifampicin (RIF) resistance is highly correlated with isoniazid (INH) resistance and used as proxy for multidrug-resistant tuberculosis (MDR-TB). Using MTBDRplus as a comparator, we evaluated the predictive value of Xpert MTB/RIF (Xpert)–detected RIF resistance for MDR-TB in eastern Democratic Republic of the Congo (DRC).

Methods

We conducted a cross-sectional study involving data from new or retreatment pulmonary adult TB cases evaluated between July 2013 and December 2016. Separate, paired sputa for smear microscopy and MTBDRplus were collected. Xpert testing was performed subject to the availability of Xpert cartridges on sample remnants after microscopy.

Results

Among 353 patients, 193 (54.7%) were previously treated and 224 (63.5%) were MTBDRplus TB positive. Of the 224, 43 (19.2%) were RIF monoresistant, 11 (4.9%) were INH monoresistant, 53 (23.7%) had MDR-TB, and 117 (52.2%) were RIF and INH susceptible. Overall, among the 96 samples detected by MTBDRplus as RIF resistant, 53 (55.2%) had MDR-TB. Xpert testing was performed in 179 (50.7%) specimens; among these, 163 (91.1%) were TB positive and 73 (44.8%) RIF resistant. Only 45/73 (61.6%) Xpert-identified RIF-resistant isolates had concomitant MTBDRplus-detected INH resistance. Xpert had a sensitivity of 100.0% (95% CI, 92.1–100.0) for detecting RIF resistance but a positive-predictive value of only 61.6% (95% CI, 49.5–72.8) for MDR-TB. The most frequent mutations associated with RIF and INH resistance were S531L and S315T1, respectively.

Conclusions

In this high-risk MDR-TB study population, Xpert had low positive-predictive value for the presence of MDR-TB. Comprehensive resistance testing for both INH and RIF should be performed in this setting.