bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Iron Oxide (Fe2O3) on the Properties of Fly Ash Based Geopolymer
Authors: Zailani W W A , Abdullah M M A , Arshad M F , Burduhos-Nergis D D , Tahir M F M
Published: July 2020

Geopolymer is an attractive construction binder owing to its ability to improve the properties of the concrete and preserves the environment from the high CO2 emission. Geopolymer technology will convert the potential hazardous industrial waste such as fly ash into valuable construction materials. However, there is a need of studying the properties of iron-based geopolymer in order to enhance the fundamental and knowledge of the geopolymer research also development in this study area. Fly ash which contains a significant amount of iron oxide (Fe2O3) was used as a precursor and tested at different curing duration (1, 3, 7, 14 and 28 days). Crystallization of iron oxide (Fe2O3) contained in the fly ash under geopolymerization process will be able to turn waste fly ash into a strong concrete materials, simultaneously creating a waste-to-wealth economy. Furthermore, the formation of fayalite detected from the microstructure characterization is mainly contribute to the strength development of the fly ash after 28 days curing.
Influence of the Stand-off Distance and of the Layers Thickness on the Adhesion and Porosity of the 97MXC Deposits Obtained by Arc Spraying Process
Authors: Haraga R A , Chicet D L , Cimpoiesu N , Toma S L , Bejinariu C
Published: July 2020

In this paper, the surfaces of some weakly alloyed steel specimens were covered, by arc spraying process, with a layer of high alloyed steel: 97MXC, using core wires. The technological parameters, used to spray the high alloy steel, were kept constant except for the spray stand-off distance (SOD) which varied on three levels. The research was performed on deposits with a thickness between 0.2-2.4 mm. The microstructure of the deposits, the chemical composition, the physical properties of the layers were investigated by SEM analyzes, X-ray diffraction, microhardness tests and adhesion tests. The porosity of the deposits was determined by optical microscopy. The adhesion of the layer to the substrate was researched by the tensile test. Studies have shown the fact that SOD significantly influences the adhesion and porosity of the deposits. Thus, the increase of SOD determines the decrease of the adhesion of the layer to the substrate by approximately 21.4%, the increase of the porosity of the deposits by approximately 14.2% and variations up to 5% of the microhardness.
CNC End Milling Process Parameters Optimization on Aluminium Alloy by Using Taguchi and ANOVA Methods
Authors: Țîțu M A , Pop A B
Published: July 2020

This paper is focused on the experimental research which is carried out on the machining of the aluminum alloy. Its main objective is to find the optimum cutting parameters used in the end-milling process. An experimental plan was established based on the L27 orthogonal matrix. The experiments were performed using the recommended values for the cutting parameters by the cutting tools manufacturer on the aluminum machining. The design of experiment methods that were used, are the Taguchi method, the variance analysis and the regression analysis. The controllable factors were the cutting speed, the cutting depth and the feed per tooth. The surface roughness represents the objective function and this was obtained by the studied cutting process. The surface roughness was measured longitudinally and transversely in the cutting direction.
Development of Cement-Based Materials Enriched with Polymeric Coated Reactive Grains as Long-Term Promoter of Matrix Continuous Hydration
Authors: Voinitchi C , Baeră C , Zapciu M , Matei C , Szilagyi H
Published: July 2020

The continuing hydration of unhydrated cement grains was proven to be one of the most important processes for promoting the self-healing effect within cementitious composites, by generating the CSH gels as valuable healing products, not only sealing the microcracks but also being able to provide some mechanical recovery of the material, as well [1]. It was also concluded that the process slows down in time, being strongly connected to concrete age. In order to ensure the continuous hydration potential for the cementitious materials, also as essential self-healing (SH) promoter, the addition of reactive grains is considered. This paper presents preliminary aspects regarding the possibility of polymeric encapsulation of some reactive grains and the feasibility of the concept in terms of matrix compatibility to the addition and also their SH performance under induced, controlled cracking. The considered self-healing addition behaves intelligent as it would react with water only when the cracking occurs, creating gaps in the waterproofing coating. The object of this research is less focused on regaining the mechanical characteristics of concrete, like pre-cracking strength, but mainly on preventing aggressive agents from entering in the concrete mass and aggressing the reinforcement.
Electrochemical Behaviour of Ti-Mo Alloys for Medical Application in Biological Solution
Authors: Bӑlţatu M S , Vizureanu P , Bӑlţatu I , Nergis D D Burduhos , Achitei D C , Perju M C
Published: July 2020

Nowadays, primordial concern represent population health with all materials that are used in medical applications. It were obtained three alloys of titanium with addition of elements like molybdenum, zirconium and tantalum, in a vacuum arc melting furnace (VAR), in argon atmosphere. These alloys were investigated in biological solution, similar with to the human body by electrochemical study method (linear and cyclic polarization). Results revealed that it possesses a good behaviour which does not influence the human body, with future applications in medical field.
New Materials and Processes Developed for Cranioplasty
Authors: Mates I M , Semenescu A , Dumitrescu S I , Vidu R
Published: July 2020

Traumatic brain injury is the leader in the ranking of mortality and invalidity. The surgical repair of a defect of the skull by cranioplasty has been practiced since ancient times, when materials of non-biological origin were used for this purpose. New materials and processes are sought to improve osseintegration of implants. Like any surgical procedure, cranioplasty involves complications that may be related to the surgical technique and/or to the patient’s tolerance to the material used. This work described a biocompatible medical device that include two supported meshes for providing mechanical strength and osseointegration properties of the implant, and a multiplayer porous material in between them that is loaded with the required bioactive antibacterial compound to promote a controlled and sustained release of the pharmaceutical agents at the site of surgical intervention. To increase osseointegration, meshes are designed with an open structure and coated with biocompatible materials such as hydroxyapatite. The composition gradient in the multilayer porous material is attained by loading successive layers of porous material with different amounts of bioactive materials and then stacking them to create a gradient of composition across the porous material.
Experimental Investigation on the Development of Geopolymer Paving Blocks by Using Romanian Local Raw Materials
Authors: Lӑzӑrescu A , Szilagyi H , Baerӑ C , Hegyi A , Meița V
Published: July 2020

For the world economic system cement and concrete are indispensable elements for the construction industry. Demand for concrete, hence for cement, is constantly growing, especially in highly developed countries, which means that alternative binders are urgently required to meet the needs of millions of people, without compromising the CO2 levels of the atmosphere. Although environmental issues are currently not sufficiently convincing to create a sufficiently high demand for the production of geopolymer technology, this is expected to increase with the imposition of rules on carbon dioxide emissions and their effects. Preliminary alkali-activated geopolymer concrete mixtures were developed based on a rigorous trial-and-error process in order to establish the mechanical properties of the geopolymer paving blocks. The aim of this paper is to present results regarding the technology of development and optimisation for the production of geopolymer paving blocks, their mechanical properties and implementation possibilities in accordance with the intended scope of use. The study results indicate that alkali-activated geopolymer paving blocks have excellent mechanical properties, by reference to OPC paving blocks, making them suitable for practical applications.
Designing Concrete with Self-healing Properties Using Engineered Cementitious Composites as a Model
Authors: Mircea A C , Toader T P
Published: July 2020

Engineered Cementitious Composites (ECC), also known as Strain Hardening Cement-based Composites, are an easily molded mortar-based composites reinforced with polymer fibers. ECCs are designed based on micromechanics and fracture mechanics theory, to feature large tensile ductility and a variety of unique properties, including tensile properties, superior to other fiber-reinforced composites. The properties of ECCs can be custom-tailored through micromechanics design due to the interaction between the fibers and cement matrix. A structural deterioration of ECC is avoided because the fibers do not allow cracks with large widths to form, unlike conventional concrete. ECCs have the capacity to bend, generating a flexible material. Ductile properties rather than brittle had increased, unlike ordinary concrete, leading to a wide variety of applications. Obtaining superior characteristics for ECC, both in fresh and hardened state, a transition from ECC paste to concrete with self-healing properties was made. To obtain self-healing concrete, with same ECC paste behavior and characteristics, the mix-design of the paste was optimized. The aim of this article is to present the experimental results regarding the transition from ECC paste to self-healing concrete and to analyze the results in order to establish a mix-design pattern for concrete with self-healing properties.
Influence of Primary Power Source on Heat-insulating Material Choice for Autonomous Telecom Unit Container
Authors: Kiseleva S , Tarasenko A , Fedotov A
Published: July 2020

The paper is devoted to the energy balance estimation for autonomous telecom unit, powering from photovoltaic panels and diesel-fuelled genset. Unit container has its own heat balance, basing on climate control system and parasite heating from telecom equipment inside it. Climate control system is also considered as power consumer from PV or genset. Obviously this power consumption depends on unit load graph, heat exchange with environment, environmental temperature. Energy and economical analysis has been conducted for several possible unit geographical locations, three types on heat-insulating materials and different share of solar energy in energy balance. It has been shown that in case of diesel fuel domination in energy balance and not very low environmental temperature heat-insulating material with lowest heat conductivity is not an optimal choice from operational expanses point of view (through high fuel consumption in summer for the container cooling).
Expanded Foam Glass - an Application for Fire Resistant Multilayer Materials
Authors: Mocanita O , Chicet D L , Rusu O , Istrate B , Munteanu C
Published: July 2020

This study is focused on obtaining a fire-resistant multilayer material, which includes in the structure a layer with properties of high temperature resistance and low heat transfer. One of the research directions is focused on obtaining such a layer using expanded glass granules with two different dimensional ranges noted with A (1 - 2 mm) and B (0.25 - 0.5 mm). The target layer was realized with the shape of square plates of 50 × 50 mm, with a thickness of 5 and 10 mm respectively, from a mixture of quartz sand with a polymeric resin as bonding agent in which the expanded glass granules were inserted. The following samples were obtained: P5A and P5B (5 mm thick plates), respectively P10A and P10B (10 mm thickness plates). The samples were analyzed both from the morphological point of view (the emphasis being placed on the structure distribution of the expanded glass granules) and from the point of view of the resistance to high temperatures (by indirect exposure at temperatures between 400 - 600 ° C for 3 hours). The satisfactory behavior of the samples during the tests recommends the extension of the researches in this direction, in order to establish the optimal percentage of component elements.
The Effect of H2O2 and Lactic Acid Addition in Biological Saliva on the Corrosion Behaviour of 304L Stainless Steel
Authors: Simionescu N , Benea L , Chiriac A
Published: July 2020

The aim of this study is to assess the corrosion resistance of SS304L in biological solution (named Ringer) at body temperature 370 C. The addition of H2O2 and C3H6O3 simulate the presence of microorganism metabolic product and inflammatory conditions. 304L stainless steel, in the oral cavity, can interact with other product capable of initiating corrosion of metals. H2O2 was used because is delivered by leukocytes and microscopic organism (bacteria) occurs in conditions in which the human body suffers a process of inflammation and lactic acid can be produced by a bacterial strain called Streptococcus mitis meeting in the dental plaque. For corrosion investigations was used in situ measurement (electrochemical) such as: OCP (open circuit potential) and EIS (electrochemical impedance spectroscopy). The electrochemical results conclude that the additions of hydrogen peroxide and lactic acid as well as these two compounds in combination have influence on the corrosion behaviour of SS304L in Ringer saliva.
Contributions to the Development of a Low-Speed Gadolinium Actuator System
Authors: Toader V E , Ungureanu C , Milici L D
Published: July 2020

Within the EMAD Research Centre of the USV, a low-speed actuator system has been developed which is based on the properties of the intelligent material gadolinium, i.e. the modification of the magnetic properties of the material according to temperature, magnetic at a temperature of less than 22.5 degrees and paramagnetic at a temperature greater than 22.5 degrees. The speed adjustment is made by the temperature variation (cold - warm). The paper presents the constructive solution, experimental data from which the characteristics of the equipment designed, carried out and tested and the general conclusions on its implementation in industrial actuator systems.
Influence of Microparticles on Setting Time and Micromorphology of Coal Ash Geopolymers
Authors: Burduhos Nergis D D , Vizureanu P , Țopa D , Minciuna M G , Abdullah M M A B
Published: July 2020

Geopolymers are inorganic materials with zeolites-like microstructure and mechanical properties similar to those of Ordinary Portland cement materials [1]. However, their properties are highly depending on the constituents (raw material and activator) characteristics, as well as, on the activation particularities (mixing parameters, curing time and temperature etc.). In order to explore the influence of partial replacement of coal ash with two types of fine aggregates (glass and sand microparticles) on micromorphology and setting time, four types of geopolymers were developed. The evaluations were performed by means of electronic microscopy and Vicat method. According to this study, the coal ash replacement with glass microparticles results in an increase in the initial and the final setting time, while the replacement of coal ash with sand particles show a significant decrease. Moreover, the microstructural analysis shows different behaviour, during activation, of the studied microparticles. The surface of the glass microparticles reacts in the alkaline environment, while the sand particles did not. Therefore, the increase of initial and final setting time can be correlated with the dissolution of Si-O from the glass particles, during geopolymerisation.
Temperature Deformation Influence on the Locking Equipment Destruction in Water Supply Systems at High-Rise Buildings Upper Floors
Authors: Antimonov A , Pushkareva N
Published: July 2020

The locking equipment in water supply systems destruction problem on the upper floors of high-rise buildings is being solved. After destruction products quality study did not reveal defects of a metallographic nature or rejects in manufacture. Therefore, the hypothesis that the destruction cause is low-cycle material fatigue under the dynamic loads influence, arising due to temperature deformations in the pipeline, was proposed. In this paper, we consider a pipeline scheme in which a temperature gradient arises in the fluid flow direction. At different temperature strains of the pipeline parts bending stresses emerge. These stresses cyclic nature is determined by the hot- and cold-water consumption frequency. The pipeline model where the locking equipment was installed is a beam with pinched ends. The bending stresses calculation for this beam was performed using the initial parameter method. Plots of moments and transverse forces in the beam section are plotted. The permissible stress calculation under the dynamic loads action was made. The pipeline section size, within which shut-off equipment can be installed without destruction, was determined.
Studies on Two Icons Oklads with the Representation of St. Great Martyr George
Authors: Bivol L R , Ghica V G , Petrescu M I , Iacob G , Vasile E , Buzatu M , Gheorghe D , Kovács T A
Published: July 2020

The work represents a comparative study of two icon oklads representing St. George killing the dragon: the first of Romanian origin according to the stamp with the silver title “12” - examples of Romanian oklads with this silver title can be found in the works of S.S. Duicu, and the second oklad with stamps that seem to be specific to Russian silverware workshops. The Romanian icon oklad depicting St. George killing the dragon has in the central-lower part two stamps - the first stamp represent the monogram of master controller or craftsman or silver master “KΠ”, and the second represents the silver title “12”. The initials of the master are written in Cyrillic letters, as well as the inscription from the upper part of the oklad “C.ΓEOPΓIE”. The investigations on the two icons oklads were achieved through XRF analysis performed with a portable X-MET 5000 Oxford analyzer (Oxford X-MET 5000 Handheld XRF Analyzer) and SEM-EDX analyzes performed on a Phillips XL-30-ESEM electron microscope using a Quanta Inspect F50, with a field emission gun (FEG) with 1.2 nm resolution and an Energy Dispersive X-ray Spectrometer (EDXS) having 133 eV resolution at MnKa. Following the analyses it was observed that the silver title 84 stamped on the Russian icon oklad does not correspond to reality.
Instrumental Analytical Techniques Applied to Old Gate Tower from Corvins’ Castle
Authors: Ion R M , Tincu S , Minca I , Dulama I D , Bucurica I A , Ion M L , Gheboianu A I
Published: July 2020

Nowadays, a better understanding of the factors (including environmental) that influence the degradation of materials from different buildings and monuments, is absolutely necessary. In this paper some analytical techniques, as Fourier Transformed IR Spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF), optical microscopy (OM) and SEM-EDS, have been used for evaluation the structure and chemical composition and the characterization of the degradation products, causes and mechanisms of disintegration / degradation of materials and aging processes. Few samples from the Old Gate Tower of the Corvins’Castle, Hunedoara, have been collected and subjected to be analysed and fruitful conclusions have been obtained referring to the raw materials provenance and weathering / deterioration processes which they supported. Similar minerals with those identified at the other towers from Corvins’Castle have been evidenced: quartz, calcite and dolomite, being majority, and additional apatite minerals. Also, ion chromatography could be used to identify the presence of different ions, responsible for the accelerated process of the monument’s walls.
On the Security of a Smart City SDN-Based Network
Authors: Scripcariu L , Mӑtӑsaru P D , Mocanu F
Published: July 2020

Our research work focuses on the security techniques applied on a software-defined network (SDN), designed for a smart city. Information security is essential for the good functionality of the applications used in a smart city. Information should be correct and complete otherwise the ‘life’ of the city can be compromised by various cyberattacks targeting, for example, the public transportation system, the traffic information on highways or location services for emergency crews and many others. Securing all devices connected to the SDN, including end-user devices, wireless sensors, smart home equipment is essential because various cyberattacks may be launched and the smart city may be disturbed. This paper presents a risk analysis, the ways to choose the security solutions according to the smart city security policy and our proposal for the SDN security system. We compare different security techniques and present some recommended solutions.
Considerations Regarding the Recalibration of the Manufacture of Castings from the Perspective of the Development of the Circular Economy
Authors: Soporan V F , Vescan M M , Lehene T R , Pӑduretu S , Gabor T
Published: July 2020

The paper presents the issue of recalibration of cast parts from the perspective of the circular economy, by presenting the specific issue, by setting the main objective of the study, that of identifying areas that require interventions in the technological process and ensuring socio-economic functionality. The analysis, in general, includes the presentation of the specifics of the analyzed process, the construction of assessment indicators of the circular economy and the quantification and hierarchy of the influencing factors. Particular attention is paid to the quantitative indicators and value appreciation of the manufacture of castings to the rigors of the circular economy. At the level of interpretive analysis, are presented the critical areas that require a multidisciplinary intervention to ensure the specific conditionalities of the circular economy.
Innovation for Trap Particle and Eliminate Germs in Air By Corona Electrostatic System
Authors: Ketkaew S
Published: July 2020

This article presents an innovation for trap particle and eliminate germs in air by corona electrostatic system. The air circulation rate is 165 cubic meters per hour by designing the power supply with IC#TL494. The IC#TLP250 uses separate ground and drive Power MOSFET#IRFP460 by bringing DC high voltage from the transformer#TLF14511 to the dust collector unit and the electron separation unit. By designing and building a machine capable of trapping dust particles smaller in size from 0.3 microns up to the results of the tests showed that the dust collecting efficiency of 95.37% from the experiment by measuring the amount of dust using Personal pump and the dust collection efficiency of 95.86% from measuring dust using Handy laser partical counter and part of electron separation can produce corona for producing ozone gas up to 3 ppm to eliminate bacteria in the air. The UV lamps for ozone emissions are reduced to 0.1 ppm for disaster prevention to users.
Cellulosic and Tannins Containing Wastewater Treatment Using MBBR Technology and Fungal Strain
Authors: Moga I C , Iordache O G , Petrescu G , Mitran E C , Tanasa A G , Sandulache I , Pantazi G A , Secareanu L O , Anghelache G , Lite C
Published: July 2020

Since the beginning, Mobile Bed Biofilm Reactor (MBBR) technology has been extensively used, both at the level of small on-site treatment units and at industrial scale. Moreover, this technology represents a starting point for many researches aimed at improving performance, such as the use of microorganisms, enrichment with anammox bacteria to accelerate nitrogen removal and more. Within the present paper, a new generation of carriers (consisting of a mix of high-density polyethylene + talcum + cellulose) was bio-augmented with a WRF (White Rot Fungi) strain, namely Cerioporus squamosus, in static conditions (data not shown in this paper). The wastewater, targeted for treatment, originated from National R&D Institute for Textile and Leather, INCDTP Bucharest, leather subsidiary, Leather and Footwear Research Institute, technological flux, characterized by high tannins concentration, and cellulosic content. Wastewater treatment aimed the reduction of COD value, as a water quality parameter, with satisfactory results, obtaining a percentage reduction rate of 48.53%. Also, GC-MS chromatography analysis was carried out on five vegetal tannins, used in leather treatment, highlighting main compounds for Mimosa, Chestnut, Gambier, Myrobalan and Quebracho natural tannins.
Comparison of Total Phenolic Content, Antioxidant Activity and Extraction Yield from Apium Graveolens Waste Using Unconventional Extraction Methods
Authors: Spînu S , Orţan A , Ionescu D , Moraru I , Drugulescu M
Published: July 2020

Apium graveolens is a medicinal and aromatic plant used in pharmaceutical industry, cosmetic industry, gastronomy and traditional medicine. Aerial parts of Apium graveolens (stems and leaves) are rich in bioactive compounds (flavonoids, phenols, furanocoumarins, volatile oils, sesquiterpene alcohols, fatty acids, etc.). It is known for its hepatoprotective, antioxidant, anticancer, antidiabetic, anti-inflammatory, antimicrobial, analgesic, anti-spasmolytic, anti-infertility, cardiotonic activities. This is why studies in this direction have not yet ceased and are increasingly pursuing the discovery of new, unconventional methods for identifying, quantifying and isolating bioactive compounds from Apium graveolens waste. The aim of this study was to determine and correlate the total phenolics, total flavonoids, antioxidant activity and extraction yield from ethanolic extracts (70%) of stems and leaves waste with different unconventional extraction methods. Apium graveolens aerial parts waste were obtained after aqueous extraction of the leaves and stems. The extraction yield was expressed as function of freeze-dried extracts, and the extraction methods were ultrasound assisted extraction, microwave assisted extraction and accelerated solvent extraction. Regarding the chosen extraction methods, numerous studies have shown, especially in the case of microwave assisted extraction, the presence of bioactive compounds in plant waste, in a reasonable percentage, therefore this study aimed to identify an optimal extraction method also in the case of Apium graveolens aerial parts waste. Total phenols content was determined by Folin-Ciocalteu spectrophotometric method, the flavonoids content waste determined by aluminium chloride spectrophotometric method and the antioxidant activity was studied using DPPH (2,2-Diphenyl-1-picrylhydrazyl) spectrophotometric method. The findings of this work indicated a positive dependence between the extraction yield of the waste material and the considerable content of bioactive compounds still present (phenols and flavonoids) for all considered extraction methods.
Reducing Power Consumption in Smart Monitoring Systems with BLE Wireless Technology
Authors: Ştoica C , Mӑtӑsaru P D , Scripcariu L
Published: July 2020

This research focuses on alternative low power consumption in smart monitoring systems and on various techniques to facilitate access to different monitoring sensors connected via Bluetooth Low Energy (BLE). Due to high complexity and power demands that new smart monitoring equipment have, the need for reduced power consumption in the context of new regulations/architectures for the Internet of Things has occurred. Sensors can have dimensions of a few centimeters, are not required to have cabling or power supply and can transmit data for a long period of time. A network of sensors connected through BLE wireless technology with a corresponding architecture can provide a simple and versatile solution to multiple environments that need to be monitored. Data provided by the smart monitoring systems must be carried and analyzed either in upper layers of the network or close to the edge. Dedicated applications allow users to access data via smart-devices and data can be downloaded on any device, such as mobile phones. All these require communication technologies with optimized and reduced power consumption, also increasing battery lifetime and becoming more eco-friendly.
Simulation of Pedestrian Walking Through Angled-Corridors for Evacuation Behaviour Study
Authors: Rahman N A , Alias N A , Sukor N S A , Halim H , Gotoh H , Hassan F H
Published: July 2020

The effect of acute- and obtuse-angled-corridors on the evacuation behaviour is rarely studied. In the previous work, we have confirmed that corridor with less than 90° turning angle has negative impact to the pedestrians walking behaviour due to the tendency of the pedestrians to slow down their motion when approaching the turning of the corridor. This restrict the flow of walkers during high-density situation and cause congestion near that turning of the corridor. In this contribution, empirical data collected from previous experimental work is utilised to further study the effect of turning angle on the evacuation behaviour. The simulations of walking through angled-corridor were reproduced which reflects evacuation scenarios. Three different types of angled-corridor are taken into consideration (a 60°-, a 90°-, and a 135°-angled-corridors) with different sets of number of pedestrians (NOP: 60, 70, 80, 90 and 100). Three metrics of evacuation behaviour measurement are reported: (1) inflexion points, (2) escape time, and (3) interaction force. Inflexion point is used to evaluate the restriction flow occurred during the evacuation. From the results, the 60° angled-corridor contained the highest number of inflexion points. With the highest number of inflexion points, the escape time for the 60° angled-corridor is 14.8% to 24% longer compared to the other two types of angled-corridors. This shows that this kind of angled-corridor need to be avoided in the future design of walkways. On top of that, the 60° angled-corridor also gives the maximum interaction force with 213.75 N. This reconfirmed that the corridor with less than 90° turning angle is not suitable to be built as a walkway. This work is relevant to be studied due to its immediate applications in assessment of crowd safety for building egress.
Polyester Dyeing and its Environmental Impact
Authors: Manea L R , Bertea A-P , Bertea A
Published: July 2020

Dyeing and printing of textiles are responsible for 30% of the pollutants contained in the effluents. The impact of textile dyeing processes on environment is highly variable, most important issues being the colour, the organic charge, and the solids in suspension. The present study investigates the characteristics of the polyester dyeing process in what concerns the environmental issues. Disperse dyes are non ionic, have very limited solubility in water at room temperature and have substantivity for polyester fibre. Two disperse dyes were used, and dyeing were performed at different concentrations. The exhaustion degree, the volume of wastewater used in the process, the specific flow, pH, temperature and chemical oxygen demand of the wastewater, the total residuum, volatile substances and the biological oxygen demand were determined in all the cases. The data obtained showed that the global pollutant content of the wastewater from disperse dyes dyeing is high (more than two times higher than those obtained in the case of dyeing with acid dyes). Absorption spectra of the initial and exhausted dyebath were determined, in order to evaluate the dilution degree needed to make wastewater colour acceptable.
Climate scientist John Houghton dies aged 88
Authors: Banks Michael
Published: July 2020

John Houghton, the physicist who spent 14 years as head of the scientific assessment working group of the International Panel for Climate Change (IPCC), died on 15 April at the age of 88.
From ‘techno-turkey’ to iconic observatory
Authors: Cooper Keith
Published: July 2020

Launched in 1990, the Hubble Space Telescope has almost single-handedly transformed astronomical research and altered the public’s perception of space. Now, three decades on, attention is turning to its successor, as Keith Cooper reports
Shock and awe?
Authors: Crease Robert P
Published: July 2020

How do you react when something unexpected happens in physics? Robert P Crease runs through the gamut of emotions
Why ultrafast is ultra-good
Authors: Tsoumpas Charalampos
Published: July 2020

Researchers have long sought to observe fast-moving events at ever-higher speeds. Charalampos Tsoumpas explains why our ability to track gamma rays emitted just picoseconds apart could lead to a new generation of medical-imaging devices
NASA satellite data highlight Antarctic ice loss
Authors: Randall Ian
Published: July 2020

Losses from the ice sheets of Antarctica and Greenland in the last 16 years have far outpaced snow accumulation according to researchers at the University of Washington.
What Now? Epidemiology in the Wake of a Pandemic
Authors: Edwards Jessie K , Lessler Justin
Published: July 2020

The coronavirus disease 2019 (COVID-19) pandemic and the coming transition to a postpandemic world where COVID-19 will likely remain as an endemic disease present a host of challenges and opportunities in epidemiologic research. The scale and universality of this disruption to life and health provide unique opportunities to study phenomena and health challenges in all branches of epidemiology, from the obvious infectious disease and social consequences to less clear impacts on chronic disease and cancer. If we are to both take advantage of the largest natural experiment of our lifetimes and provide evidence to inform the numerous public health and clinical decisions being made every day, we must act quickly to ask critical questions and develop new methods for answering them. In doing so, we should build on each of our strengths and expertise and try to provide new insights rather than become yet another voice commenting on the same set of questions with limited evidence.
Changes of Tissue Factors and Tissue Factor Pathway Inhibitors in the Acute Phase of Cardiogenic Stroke in Patients With Atrial Fibrillation
Authors: Chen Yong-li , Chen Juan , Yang Li , Huang Kui , Ma Yu , Ren Ning , Jiang Hua
Published: July 2020

Background

To investigate changes of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in the acute phase of cardiogenic stroke in patients with atrial fibrillation (AF).

Methods

A total of 152 patients with nonvalvular persistent AF, 103 cardiogenic stroke patients with nonvalvular persistent AF, and 126 cases with noncardiogenic stroke were enrolled. Non-AF patients (n = 138) without stroke served as controls. The clinical data, biochemical indicators, and plasma levels of von Willebrand factor (vWF), TF, and TFPI were determined.

Results

Compared with controls, the plasma levels of vWF and TF were significantly higher, while TFPI and TFPI/TF ratio were lower in noncardiogenic stroke patients (all P < 0.05). Compared with cardiogenic stroke patients, noncardiogenic stroke subjects showed significantly higher plasma vWF and TF levels while TFPI levels and TFPI/TF ratio were significantly lower (all P < 0.05). Compared with AF patients, plasma levels of vWF, TF, and TFPI were higher while TFPI/TF ratios were decreased in the cardiogenic ischemic stroke subjects (all P < 0.05). Logistic regression analysis showed that a lower TFPI/TF ratio was an independent predictor of cardiogenic stroke in patients with nonvalvular AF (odds ratio = 3.78, 95% confidence interval: 1.86–7.31).

Conclusions

During the acute stage of stroke, TFPI/TF ratio is decreased in both cardiogenic and noncardiogenic stroke patients while plasma TFPI levels show divergent changes.
Post-exercise respirometry underestimates maximum metabolic rate in juvenile salmon
Authors: Raby Graham D , Doherty Claire L J , Mokdad Ali , Pitcher Trevor E , Fisk Aaron T
Published: July 2020

Experimental biologists now routinely quantify maximum metabolic rate (MMR) in fishes using respirometry, often with the goal of calculating aerobic scope and answering important ecological and evolutionary questions. Methods used for estimating MMR vary considerably, with the two most common methods being (i) the ‘chase method’, where fish are manually chased to exhaustion and immediately sealed into a respirometer for post-exercise measurement of oxygen consumption rate (ṀO2), and (ii) the ‘swim tunnel method’, whereby ṀO2 is measured while the fish swims at high speed in a swim tunnel respirometer. In this study, we compared estimates for MMR made using a 3-min exhaustive chase (followed by measurement of ṀO2 in a static respirometer) versus those made via maximal swimming in a swim tunnel respirometer. We made a total of 134 estimates of MMR using the two methods with juveniles of two salmonids (Atlantic salmon Salmo salar and Chinook salmon Oncorhynchus tshawytscha) across a 6°C temperature range. We found that the chase method underestimated ‘true’ MMR (based on the swim tunnel method) by ca. 20% in these species. The gap in MMR estimates between the two methods was not significantly affected by temperature (range of ca. 15–21°C) nor was it affected by body mass (overall range of 53.5–236 g). Our data support some previous studies that have suggested the use of a swim tunnel respirometer generates markedly higher estimates of MMR than does the chase method, at least for species in which a swim tunnel respirometer is viable (e.g. ‘athletic’ ram ventilating fishes). We recommend that the chase method could be used as a ‘proxy’ (i.e. with a correction factor) for MMR in future studies if supported by a species-specific calibration with a relevant range of temperatures, body sizes or other covariates of interest.
Population Genomic Analyses of the Sea Urchin Echinometra sp. EZ across an Extreme Environmental Gradient
Authors: Ketchum Remi N , Smith Edward G , DeBiasse Melissa B , Vaughan Grace O , McParland Dain , Leach Whitney B , Al-Mansoori Noura , Ryan Joseph F , Burt John A , Reitzel Adam M
Published: July 2020

Extreme environmental gradients represent excellent study systems to better understand the variables that mediate patterns of genomic variation between populations. They also allow for more accurate predictions of how future environmental change might affect marine species. The Persian/Arabian Gulf is extreme in both temperature and salinity, whereas the adjacent Gulf of Oman has conditions more typical of tropical oceans. The sea urchin Echinometra sp. EZ inhabits both of these seas and plays a critical role in coral reef health as a grazer and bioeroder, but, to date, there have been no population genomic studies on this or any urchin species in this unique region. E sp. EZ’s life history traits (e.g., large population sizes, large reproductive clutches, and long life spans), in theory, should homogenize populations unless nonneutral processes are occurring. Here, we generated a draft genome and a restriction site-associated DNA sequencing data set from seven populations along an environmental gradient across the Persian/Arabian Gulf and the Gulf of Oman. The estimated genome size of E. sp. EZ was 609 Mb and the heterozygosity was among the highest recorded for an echinoderm at 4.5%. We recovered 918 high-quality SNPs from 85 individuals which we then used in downstream analyses. Population structure analyses revealed a high degree of admixture between all sites, although there was population differentiation and significant pairwise FST values between the two seas. Preliminary results suggest migration is bidirectional between the seas and nine candidate loci were identified as being under putative natural selection, including one collagen gene. This study is the first to investigate the population genomics of a sea urchin from this extreme environmental gradient and is an important contribution to our understanding of the complex spatial patterns that drive genomic divergence.
Positive Selection and Gene Expression Analyses from Salivary Glands Reveal Discrete Adaptations within the Ecologically Diverse Bat Family Phyllostomidae
Authors: Vandewege Michael W , Sotero-Caio Cibele G , Phillips Caleb D
Published: July 2020

The leaf-nosed bats (Phyllostomidae) are outliers among chiropterans with respect to the unusually high diversity of dietary strategies within the family. Salivary glands, owing to their functions and high ultrastructural variability among lineages, are proposed to have played an important role during the phyllostomid radiation. To identify genes underlying salivary gland functional diversification, we sequenced submandibular gland transcriptomes from phyllostomid species representative of divergent dietary strategies. From the assembled transcriptomes, we performed an array of selection tests and gene expression analyses to identify signatures of adaptation. Overall, we identified an enrichment of immunity-related gene ontology terms among 53 genes evolving under positive selection. Lineage-specific selection tests revealed several endomembrane system genes under selection in the vampire bat. Many genes that respond to insulin were under selection and differentially expressed genes pointed to modifications of amino acid synthesis pathways in plant-visitors. Results indicate salivary glands have diversified in various ways across a functional diverse clade of mammals in response to niche specializations.
ROM1 contributes to phenotypic heterogeneity in PRPH2-associated retinal disease
Authors: Strayve Daniel , Makia Mustafa S , Kakakhel Mashal , Sakthivel Haarthi , Conley Shannon M , Al-Ubaidi Muayyad R , Naash Muna I
Published: July 2020

Peripherin 2 (PRPH2) is a retina-specific tetraspanin protein essential for the formation of rod and cone photoreceptor outer segments (OS). Patients with mutations in PRPH2 exhibit severe retinal degeneration characterized by vast inter- and intra-familial phenotypic heterogeneity. To help understand contributors to this within-mutation disease variability, we asked whether the PRPH2 binding partner rod OS membrane protein 1 (ROM1) could serve as a phenotypic modifier. We utilized knockin and transgenic mouse models to evaluate the structural, functional and biochemical effects of eliminating one allele of Rom1 (Rom1+/−) in three different Prph2 models which mimic human disease: C213Y Prph2 (Prph2C/+), K153Del Prph2 (Prph2K/+) and R172W (Prph2R172W). Reducing Rom1 in the absence of Prph2 mutations (Rom1+/−) had no effect on retinal structure or function. However, the effects of reducing Rom1 in the presence of Prph2 mutations were highly variable. Prph2K/+/Rom1+/− mice had improved rod and cone function compared with Prph2K/+ as well as amelioration of K153Del-associated defects in PRPH2/ROM1 oligomerization. In contrast, Prph2R172W/Rom1+/− animals had worsened rod and cone function and exacerbated retinal degeneration compared with Prph2R172W animals. Removing one allele of Rom1 had no effect in Prph2C/+. Combined, our findings support a role for non-pathogenic ROM1 null variants in contributing to phenotypic variability in mutant PRPH2-associated retinal degeneration. Since the effects of Rom1 reduction are variable, our data suggest that this contribution is specific to the type of Prph2 mutation.
China’s leadership in the hydropower sector: identifying green windows of opportunity for technological catch-up
Authors: Zhou Yuan , Miao Zhongzhen , Urban Frauke
Published: July 2020

From the sectoral systems of innovation perspective, the windows of opportunity (hereafter referred to as WoOs) for industrial latecomers to catch-up could be opened up through abrupt changes in the technological, market, and institutional dimensions. Existing literature discusses different dimensional changes in isolation. Nevertheless, for green industries, the systemic interplay of these dimensions is of key importance; yet few studies have probed into this. These limitations in the literature are largely rooted in the lack of novel methods to detect and specify these abrupt changes, especially in a quantitative way. This paper, therefore, proposes a framework combining natural language processing methods with experts’ knowledge to detect these abrupt changes—named turbulences—by using multi-source heterogeneous data, in order to better identify the co-occurrences and interactions of turbulences across the technological, market, and institutional dimensions that have a high probability to open up WoOs. We apply this framework to analyze China’s hydropower sector as a case study. The hydropower sector is considered a “green” energy sector, in which China, as this study finds, has recently gained technological leadership. By analyzing the interactions between these multiple dimensions of WoOs, we discover that institutional turbulences proactively intertwine with other turbulences, and collectively form Green WoOs for the successful catch-up of China’s hydropower sector.
Immune-enhancing effects of glucocorticoids in response to day–night cycles and stress
Authors: Shimba Akihiro , Ikuta Koichi
Published: July 2020

Environmental cues such as the day–night cycle or stressors trigger the production of glucocorticoids (GCs) by the adrenal cortex. GCs are well known for their anti-inflammatory effects that suppress the production of inflammatory cytokines and induce the apoptosis of lymphocytes. Recent studies in mice, however, have revealed pro-inflammatory effects. The diurnal oscillation of GCs induces the expression of IL-7 receptor α (IL-7Rα) and C–X–C motif chemokine receptor 4 (CXCR4) at the active phase, which drives the diurnal homing of T cells into lymphoid organs. This accumulation of T cells at the active phase enhances T-cell priming against bacterial infection and antigen immunization, leading to an increase of effector CD8 T cells and antibody production. GCs induced by moderate stress trigger the homing of memory CD8 T cells into the bone marrow and support the maintenance and response of these cells. Thus, endogenous GCs have a self-defense function to enhance adaptive immune responses. By contrast, strong stress induces even higher GC levels and causes chronic inflammation and autoimmunity. Because GCs can enhance the differentiation and function of T-helper 2 (Th2) and Th17 cells, high stress-induced GC levels might enhance inflammation via Th17 cell differentiation. Overall, the positive and negative effects of GCs may regulate the balance between normal immune responses and susceptibility to infections and inflammatory diseases.
Rapid design and deployment of intensive outpatient, group-based psychiatric care using telehealth during coronavirus disease 2019 (COVID-19)
Authors: Childs Amber W , Unger Adam , Li Luming
Published: July 2020

COVID-19 has demanded unprecedented actions in the delivery of outpatient psychiatric services, including the rapid shift of services from in-person to telehealth in response to public health physical distancing guidelines. One such shift was to convert group-level intensive outpatient psychiatric (IOP) interventions to telehealth. Historically, telehealth in psychiatric care has been studied in provider-patient interactions, but has not been as well studied for group telehealth service delivery. During the COVID-19 outbreak, providing group-based interventions was important in order to care for high-risk individuals who needed structured psychotherapy group support. However, the delivery of services via telehealth led to special challenges that were unable to be fully accommodated by the preexisting telehealth infrastructure. Rapid feasibility testing and adoption of technology was needed to support IOP services to minimize infectious spread while delivering group services to high-risk psychiatric patients. This article describes the processes and workflows for service delivery and early results of telehealth for IOP services in 2 adolescent treatment programs. In addition, the article highlights early observations around safety and quality and the role of telehealth policy and payment.