bluuebunny/crossref_metadata_2025 huggingface dataset:
COVID-19 SALGINININ TÜRKİYE’DEKİ BANKALARIN PAY GETİRİLERİ ÜZERİNE ETKİLERİ: AMPİRİK BİR YAKLAŞIM
Authors: USLU Hakan
Published: July 2021

Covid-19 salgını tüm dünya ülkelerinin sosyoekonomik yapısını olumsuz etkilemiş, bu olumsuzlukların etkilerini en aza indirgemek için hükümetler ciddi önlemler almak zorunda kalmışlardır. Salgının olumsuz etkileri ülkelere, bölgelere hatta sektörlere göre değişiklik göstermektedir. Dolayısıyla, hükümetlerin salgının etkisini azaltmak ve gerekli önlemleri doğru şekilde alabilmesi için, salgının sektörler üzerindeki etkileri iyi analiz edilmeli ve piyasalara gerekli müdahale zamanında yapılmalıdır. Bu amaçla, çalışma Türkiye’de Covid-19 salgınının başlangıç dönemi içerisinde (10 Mart-19Haziran 2020) Borsa İstanbul’da işlem gören bankaların pay değerlerinin salgından nasıl etkilendiğini analiz etmektedir. Spesifik olarak, çalışma korona virüs vaka sayılarındaki ve CDS primlerindeki artış ve azalışların çalışmada yer alan bankaların getiri oranları üzerindeki etkisini doğrusal olmayan ve gecikmesi dağıtılmış otoregresif model (NARDL) kullanarak tahmin etmektedir. Çalışma sonuçları, çalışmada yer alan bankaların pay getiri oranları ile Covid-19 vaka sayıları arasında uzun dönemli asimetrik ilişkinin varlığını ortaya çıkarmış ve vaka sayılarındaki pozitif şokların QNB Finans Bank’ın pay getiri oranlarını negatif etkilediğini fakat Şekerbank ve Türkiye Kalkınma Bankası’nın pay değerlerini pozitif olarak etkilediğini göstermiştir. Salgın döneminde CDS primlerindeki pozitif şokların ise çalışmada kullanılan birçok bankanın pay getiri oranlarını olumsuz etkilediği gözlemlenmiştir. Çalışma salgın döneminde karar alıcılar tarafından bankacılık sektörünün desteklenmesi için uygulanacak politik ve finansal tedbirlerin belirlenmesi açısından önem arz etmektedir.
A NEW INSTRUMENT IN TURKISH FINANCIAL MARKET: SURETY BONDS
Authors: YEŞİLYAPRAK Mehmet , ERKÖK Banu
Published: July 2021

A surety bond is a three-party agreement between the contractor, the employer, and the surety in which surety ensures the contractor can fulfill the obligations regarding the contract against the employer. However, the usage of surety bonds in Turkey are quite different from USA and Europe. They are utilized in the place of letter of guarantee. Especially for the contractors with collateral shortage, the surety bond is much more advantageous than the bank letter of guarantee for the contractors since the surety bond does not reduce their credit limits within the banks. Thus, this paper aims to reveal the benefits of surety and targets increasing the awareness of surety bonds in Turkey.
Oscillatory bifurcation problems for ODEs with logarithmic nonlinearity
Authors: Shibata Tetsutaro
Published: July 2021

We study the global structure of the oscillatory perturbed bifurcation problem which comes from the stationary logarithmic Schrödinger equation

−

u

″

(

t

)

=
λ

(

log

(

1
+
u

(

t

)

)

+
sin
u

(

t

)

)

,

u

(

t

)

>
0
,

t
∈
I
≔

(

−
1
,
1

)

,

u

(

±
1

)

=
0
,

-{u}^{^{\prime\prime} }\left(t)=\lambda (\log \left(1+u\left(t))+\sin u\left(t)),\hspace{1.0em}u\left(t)\gt 0,\hspace{1.0em}t\in I:= \left(-1,1),\hspace{1.0em}u\left(\pm 1)=0,

where

λ
>
0

\lambda \gt 0

is a parameter. It is known that

λ

\lambda

is a continuous function of

α
>
0

\alpha \gt 0

, written as

λ

(

α

)

\lambda \left(\alpha )

, where

α

\alpha

is the maximum norm

α
=
‖

u

λ

‖

∞

\alpha =\Vert {u}_{\lambda }{\Vert }_{\infty }

of the solution

u

λ

{u}_{\lambda }

associated with

λ

\lambda

. In the field of bifurcation theory, the study of global structures of bifurcation curves is one of the main subjects of research, and it is important to investigate the influence of the oscillatory term on the global structure of bifurcation curve. Due to the effect of

sin
u

\sin u

, it is reasonable to expect that an oscillatory term appears in the second term of the asymptotic formula for

λ

(

α

)

\lambda \left(\alpha )

as

α
→
∞

\alpha \to \infty

(cf. [1]). Contrary to expectation, we show that the asymptotic formula for

λ

(

α

)

\sqrt{\lambda \left(\alpha )}

as

α
→
∞

\alpha \to \infty

does not contain oscillatory terms by the third term of

λ

(

α

)

\sqrt{\lambda \left(\alpha )}

. This result implies that the oscillatory term has almost no influence on the global structure of

λ

(

α

)

\lambda \left(\alpha )

. The result is, therefore, unexpected, new and novel, since such phenomenon as this is not known so far. For the proof, the involved time map method and stationary phase method are used.
Zirconium in the Nuclear Industry: 19th International Symposium
Authors: Motta Arthur T. , Yagnik Suresh K.
Published: July 2021

Description

Featuring 37 peer-reviewed and award-winning papers from industry experts that were presented at this 2019 symposium held in Manchester, United Kingdom.

Topics covered include

Sponsored by ASTM International Committee B10 on Reactive and Refractory Metals and Alloys and its subcommittee Zirconium and Hafnium.
Influence of Thermomechanical Cycling on Prehydrogenated Zircaloy-4 Embrittlement by Radial Hydrides
Authors: Desquines Jean , Puls Manfred , Charbaut Stéphane , Philippe Marc
Published: July 2021

The long-term management of spent nuclear fuel could, in France, involve transportation of spent fuel assemblies from one spent fuel pool to another, possibly ending with the assemblies located in dry storage. This situation would lead to some thermomechanical cycling, with possible effects on the fuel cladding's fracture resistance. An experimental study was performed at IRSN on nonirradiated Zircaloy-4 cladding tubes that were prehydrogenated in order to be representative of the hydrogen content of irradiated cladding. The specimens were “C”-shaped ring segments subjected to a compression load, generating a wide range of stress levels. Radial hydride treatment (RHT) consists of heating the samples to a maximum temperature of 350 or 400°C, and then cooling them at 0.4°C/min under constant compression load to room temperature. The use of a constant compression load guaranties a constant stress at any given location of the sample. The influence of a given stress level on radial hydride precipitation can consequently be evaluated at various locations in the ring to determine two possible stress thresholds: the stress below which no radial hydride precipitation is observed and the stress level above which only radial hydride precipitation is observed. Another interesting outcome is the stress level required at room temperature to nucleate a crack along a radial hydride after RHT. Load-displacement records helped to distinguish between brittle and ductile crack nucleation, which was then followed by crack instability and ductile tearing. In the present study, a large set of tests addressing the influence of hydrogen content with: 2, 5, 10, and up to 30 RHT cycles was performed at two maximum temperatures, 350 and 400°C, and these were compared to the results of formerly obtained single RHT cycle tests. The obtained results provide insights for a better understanding of the expected influence of thermomechanical cycling on irradiated cladding.
Enhanced Hydrogen Uptake and Reaction Kinetics during Oxidation of Zircaloy-4 in Nitrogen-Containing Steam Atmospheres
Authors: Grosse Mirco K. , Steinbrück Martin , Pulvermacher Samuel , Schillinger Burkhard
Published: July 2021

The authors have investigated the effect of oxygen, steam, and nitrogen on the reaction kinetics of zirconium alloys for several years. A model describing the influence of the flow rates of the reacting gases on the reaction kinetics was developed. It is well known that the presence of nitrogen in steam atmospheres can increase the reaction rate of zirconium alloys. Precipitation of zirconium nitrides results in the formation of a pronounced crack structure in the oxide layer. Such an open crack network in the oxide scale enhances the hydrogen uptake of the remaining metallic zirconium alloy detectable by neutron imaging methods. In situ neutron radiography investigations of the reaction of Zircaloy-4 in nitrogen/steam and air/steam atmospheres were performed to get more information about the reaction mechanisms and kinetics. The experiments were performed in the temperature range of 800 to 1,100°C with constant partial pressures of the gas components but varying total gas flow rates. Tests in pure steam were performed under similar conditions as a reference. The paper describes the in situ neutron radiography experiments and analyzes the results of these laboratory and radiography investigations. The reactions occur mostly as the model predicted. However, discrepancies to the model predictions were found partially at higher temperatures. This shows that additional parameters influencing the reaction behavior have to be included in the model.
The Behavior of Cr-Coated Zirconium Alloy Cladding Tubes at High Temperatures
Authors: Chaari Nermine , Bischoff Jeremy , Buchanan Karl , Delafoy Christine , Barberis Pierre , Augereau Julien , Nimishakavi Kiran
Published: July 2021

In the frame of Framatome’s “PROtect” enhanced accident tolerant fuel development program, different solutions are being investigated to improve the fuel rod’s resistance to accidental conditions. The near-term solution is a dense and adherent chromium coating applied to zirconium (Zr) alloy cladding by the physical vapor deposition technique. The main advantage of the coating is a significant reduction in the high-temperature steam oxidation that occurs under design basis accident and beyond design basis accident conditions, which leads to decreased hydrogen and heat production. However, at high temperatures, the formation of the zirconium-chromium (Zr-Cr) eutectic at approximately 1,330°C is a key point in beyond design basis accident conditions with regard to the cladding integrity and thus needs to be investigated. In this work, Cr-coated cladding samples were first characterized after high-temperature oxidation (1,000°C) and the protecting effect of the Cr coating against steam oxidation was investigated. Coated samples were also characterized after rapid heating (up to 100°C/s) in an inert atmosphere to temperatures of around 1,500°C. Electron microscopy and electron backscatter diffraction were used to identify the different phases present in the samples and to get better insight on the eutectic formation characteristics in the coated cladding. The formation of the Zr-Cr eutectic at the surface of the coated cladding was confirmed, which resulted in consumption of the Cr coating. At temperatures above ~1,330°C and within inert atmospheres, the Cr coating is consumed through two competing mechanisms: the diffusion of Cr into the Zr cladding, which remains in solid solution, and the formation of the Zr-Cr eutectic.
Fabrication of E110 Alloy Fuel Rod Claddings from Electrolytic Zirconium Base with Removing Fluorine Impurity for Providing Resistance to Breakaway Oxidation in High-Temperature Steam
Authors: Markelov Vladimir A. , Malgin Andrey G. , Filatova Nadezhda K. , Novikov Vladimir V. , Shevyakov Alexandr Yu. , Gusev Anatoly Yu. , Shelepov Ivan A. , Golovin Anton V. , Ugryumov Alexander V. , Dolgov Alexey B. , Ziganshin Alexander G. , Donnikov Vladimir E. , Latуnin Vyacheslav I.
Published: July 2021

A new technological process of manufacturing ingots for fuel rod claddings made of the electrolytic zirconium-based E110 alloy, which guarantees the removal of residual fluorine impurities in the ingot to less than the 1 ppm level, has been developed in order to ensure claddings' resistance to breakaway oxidation in high-temperature steam. The new technological process involves using electron beam melting by optimized modes as the first melting of the ingot and then at least two optimized vacuum arc melts. Pilot tubes for fuel rod claddings made of such ingots are not susceptible to breakaway oxidation in steam at a temperature of 1,000°C for 5,000 s to the oxidation state of 24% equivalent cladding reacted samples, which is similar to the behavior of fuel rod claddings made of the E110 alloy based on zirconium sponge and that meets the relevant safety criterion of a loss-of-collant design accident.
Fracture of Gamma and Delta Hydrides during Delayed Hydride Cracking
Authors: Hanlon Sean M. , McRae Glenn A. , Coleman Christopher E. , Buyers Andrew
Published: July 2021

Delayed hydride cracking (DHC) risk can be minimized by limiting hydrogen concentration, stress intensity factor, KI, and optimizing temperature maneuvers. Understanding how thermomechanical history affects bulk hydrides and DHC hydrides is critical for predicting DHC and the mechanical properties of zirconium components. On heating from a low temperature, T1, the DHC crack growth rate reaches a maximum value with temperature, T2, and then slows with further increase in temperature until cracking effectively stops, T3. This behavior is observed despite KI being greater than a threshold value, having hydrides present and a nonzero crack growth rate on cooling to the same temperature. In this study, prior DHC models have been used to predict cracking rates for past and present DHC velocity data, including more than 200 cantilever beam test specimens machined from Zr-2.5Nb plates containing 37 to 108 ppm hydrogen subjected to a variety of thermal histories, including quenching. Differential scanning calorimetry was also performed on quenched material, revealing a shift in heat flow features that contributes to an explanation for higher T2 and T3 temperatures after quenching. Examination of DHC fracture surfaces by X-ray diffraction detects the hydrides responsible for cracking; γ hydride is dominant below 125°C and δ hydride is dominant above 225°C, with a smooth transition region between these temperatures. The temperature dependence of the DHC hydride phase is not affected by thermal history. These observations are consistent with γ-phase stability at low temperatures and suggest that inferences about DHC hydrides cannot necessarily be made by observations of bulk hydrides. The results of this study can be used to improve the understanding of the effects of thermal history on DHC and lead to improved temperature maneuvering strategies, increased confidence in the structural integrity of zirconium components, and can be applied to future mechanistic modeling efforts.
Measurement of In-Reactor Stress Relaxation in Preirradiated Zirconium Alloys by Four-Point Bend Technique
Authors: Yagnik Suresh , Arimescu Ioan , Adamson Ronald , Kobylyansky Gennady , Seryodkin Sergey , Obukhov Alexander
Published: July 2021

The stress relaxation (SR) process in zirconium-based alloys is intimately related to creep behavior as stress is diminished with time by creep. Open literature data show a complex and not fully understood relation between the primary and quasi-steady-state creep rates and the corresponding SR rates; in particular, it was observed that higher primary SR rates occur under irradiation. To further investigate this topic, in-reactor SR experiments were conducted on pre-irradiated zirconium alloy specimens. A unique four-point bend (4PB) technique was applied to measure SR of pre-irradiated and unirradiated rectangular specimens (35 by 6.5 by 0.8 mm in size) at regular intervals during their irradiation in the RBT-6 research reactor and a sibling out-reactor rig. The 4PB method had never been applied previously to highly pre-irradiated (up to 34 dpa) and prehydrided (up to 339 ppm) small specimens of zirconium alloys. The measured SR behavior can be analyzed with various creep behavior models. In addition, the alloy variants tested in this study were also a subset of those from a previous study on irradiation growth behavior. The unique loading fixture utilized can simultaneously apply 4PB loads on up to six specimens, without need for removing the specimens from the fixture to record SR versus time data. Additional fast fluence accrued during SR testing in RBT-6 was minimal. Post-test examinations on selected specimens were performed by metallography and transmission electron microscopy. This paper describes (i) the design of the loading fixture, (ii) in-reactor and out-reactor SR data, (iii) the SR data trends, especially the lack of any significant dependence of SR with c-component loop density and hydrogen, (iv) some observations on the effects of alloying additions on SR, (v) application of a simple phenomenological creep model to the SR data, and (vi) the post-test characterizations of SR test samples.
Zirconium Hydride Precipitation and Dissolution Kinetics in Zirconium Alloys
Authors: Lacroix Evrard , Simon Pierre-Clément A. , Motta Arthur T. , Almer Jonathan D.
Published: July 2021

Hydride precipitation may impact the integrity of zirconium-based nuclear fuel cladding, both during normal operation and during extended dry storage. To better understand such degradation, a study of hydride precipitation of zirconium hydrides in Zircaloy-4 samples was performed. The samples were submitted to various thermomechanical cycles using both in situ synchrotron X-ray diffraction and differential scanning calorimetry. Results showed that as the hydrided samples were cooled at moderate to fast cooling rates, the hydrogen content in solid solution (CSS) decreased, following the terminal solid solubility for precipitation (TSSP) curve, reflecting hydride precipitation in the matrix. However, when the samples were held for an isothermal anneal at a fixed temperature, the CSS continued to decrease below TSSP and approached the terminal solid solubility for dissolution (TSSD). This result suggests that TSSP is a kinetic limit and that a unique solubility limit TSSD governs zirconium hydride precipitation. Hydride precipitation rate and the degree of precipitation reaction completion between 280 and 350°C were obtained using differential scanning calorimetry. Using this data, a temperature-time transformation diagram for hydride precipitation in Zircaloy-4 was generated that showed that hydride precipitation is diffusion-driven under 310°C and reaction-driven above 310°C. The experimental data were fitted to the Johnson-Mehl-Avrami-Kolmogorov model and an Avrami parameter of 2.56 was obtained (2.5 is the theoretical value for the growth of platelets). Results imply that hydride nucleation occurs if CSS is greater than TSSP while hydride growth occurs if preexisting hydride platelets are present and CSS is above TSSD. Combined with existing theory, these data were used to develop the hydride growth, nucleation, and dissolution model that can simulate hydrogen behavior in Zircaloy.
High Resolution Mapping of Light Elements in Zirconium Oxide with SIMS
Authors: Jones Christopher , Li Kexue , Liu Junliang , Aarholt Thomas , Gass Mhairi , Moore Katie L. , Preuss Michael , Grovenor Chris R. M.
Published: July 2021

The degradation of zirconium (Zr) fuel cladding alloys as a result of oxidation and the effects of hydrogen is a topic of importance to the nuclear industry. This paper presents the results of NanoSIMS studies into the corrosion behavior of Zircaloy-4 and zirconium-niobium (Zr-Nb) alloys through the use of isotopic spiking with 2H and 18O and with samples that are both irradiated and unirradiated. This paper shows that the unique capabilities of the NanoSIMS allow the study of the distribution of hydrogenic species over large areas with submicron resolution, leading to several conclusions. First, 2H and 18O have different distributions within the oxide layer, with oxygen transport being dominated by penetration through cracks, whereas hydrogen transport is largely diffusive in nature. Second, Zircaloy-4 and Nb-containing alloys show different hydrogen distributions within the oxide layer, and the hydrogen distribution in the Nb-containing alloys is strongly affected by exposure to neutron irradiation. Third, the hydrogen diffusion coefficients for Zircaloy-4, Zr-1 wt% Nb, and Zr-2.5 wt% Nb (both in and out of reactor) have been calculated and agree with previous experimental results. Finally, hydrogen in the α-Zr lattice is localized strongly to random, high misorientation grain boundaries.
Characterization of Long-Term, In-Reactor Zircaloy-4 Corrosion Coupons and the Impact of Flux, Fluence, and Temperature on Oxide Growth, Stress Development, Phase Formation, and Grain Size
Authors: Ensor Brendan , Lucadamo Gene , Seidensticker John R. , Bajaj Ram , Cai Zhonghou , Motta Arthur T.
Published: July 2021

Eleven Zircaloy-4 samples were irradiated in the Advanced Test Reactor at a variety of temperatures and neutron flux levels for up to 6.5 years. Subsequently, the coupons were characterized with complementary techniques to understand the mechanisms behind oxide growth as a function of different corrosion environments. Samples were examined using synchrotron X-ray diffraction/fluorescence, traditional X-ray diffraction, focused ion beam/scanning electron microscopy serial sectioning, and three-dimensional reconstruction to develop an improved understanding of the influence of the underlying oxide microstructure on oxide growth. The oxide microstructure formed under irradiation was compared to that in samples corroded in an autoclave to discern the impact of neutron irradiation and temperature on corrosion rate, oxide kinetic transition, irradiation-induced breakaway corrosion, stress development, phase formation, and oxide grain size. The microstructure of the oxide changed with the corrosion temperature, with larger crack spacing (characteristic of kinetic transition) and larger monoclinic oxide grains formed during higher temperature corrosion. The specimens that were exposed to a neutron flux exhibited larger oxide grains and an increase in the fraction of tetragonal phase at the metal-oxide interface (but less tetragonal phase in the bulk oxide) compared to those exposed in autoclave. Data obtained from electron microscopy demonstrated the effect of irradiation and corrosion temperature on oxide morphology. One specimen underwent an irradiated-induced breakaway oxidation that was characterized by a sharp change in the corrosion rate and a decrease in the spacing between adjacent crack layers in the oxide film. Stress is hypothesized to be a key driver in the oxide growth formation, with samples nearer transition having more plastic deformation in the metal and increased elastic strain. These observations lead to a theory of oxide growth on zirconium alloys that attempts to connect and integrate the effects of stress, irradiation, temperature, phase formation, crystal orientation, porosity, and precipitate amorphization.
Photon Irradiation Effects on Oxide Surface Electrochemistry and Oxide Microstructure of Zircaloy 4 in High-Temperature Water
Authors: Couet Adrien , He Yalong , Terrani Kurt , Armson Samuel A. J. , Frankel Philipp , Preuss Michael , Kim Taeho , Elbakhshwan Mohamed , He Li
Published: July 2021

Although there exists a correlation between autoclave and in-reactor zirconium alloy performances, consistent oxidation kinetics discrepancies in these two environments have been observed and a fundamental understanding of the oxidation kinetics enhancement under irradiation is still lacking. Recent results obtained at the Advanced Test Reactor by the Naval Nuclear Laboratory show that photon irradiation significantly affects zirconium corrosion kinetics. In reactors, various photon sources are present in the core from ultraviolet (UV) to gamma (γ) rays. This study aims at characterizing the effect of UV and γ rays on the corrosion mechanism of Zircaloy-4. To this end, a state-of-the-art autoclave equipped with sapphire windows and connected to a recirculation loop has been installed. Zircaloy-4 coupons were exposed for 7 days at 260°C with and without recirculation or UV irradiation (or both). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) oxide characterizations show the presence of iron (Fe)-rich oxide deposits on top of the zirconium oxide where the sample has been irradiated by UV. The deposit concentration is larger in the static corrosion case and does not significantly influence the zirconium oxidation kinetics. A mechanism is proposed to explain the nucleation of these deposits and the relationship to Chalk River Unidentified Deposit nucleation is discussed. In another experiment, Zircaloy-4 coupons have been irradiated at the MIT reactor in neutron+gamma, gamma, and unirradiated loop conditions. The in-core specimens were exposed to ~1021 n/m2 fast neutron fluence in 290°C water at 7 MPa. Oxide layers have been characterized by SEM and TEM. The oxide grain size, t-ZrO2 fraction, fiber texture, and m-ZrO2 twin boundaries’ density were characterized. The results indicate that, at low dpa, the neutron + γ irradiated sample has a more protective oxide than the γ-irradiated sample, which has a more protective oxide than the nonirradiated sample.
Empowering hope-based climate change communication techniques for the Gulf of Maine
Authors: Bonanno Aimee , Ennes Megan , Hoey Jennifer A. , Moberg Emily , Nelson Sarah-Mae , Pletcher Nette , Tanner Richelle L.
Published: July 2021

The Gulf of Maine is one of the fastest warming marine areas on the planet: The industries and creatures that call it home face an unprecedented shift in their interactions and existence. Scientists, policy makers, and practitioners often want to communicate to the public about the seriousness of the situation to encourage mitigation and adaptation. Many standard communication strategies that rely on fear and scientific authority alone—rather than comprehensive explanations that include solutions—can leave audiences feeling overwhelmed and disengaged, instead of hopeful and motivated to act. In this practice bridge, we showcase a social science research-based climate change communication “tool-kit” for the Gulf of Maine, using one example for each climate driver addressed at the Gulf of Maine 2050 Symposium (temperature and circulation: lobster fisheries; coastal and ocean acidification: seagrass restoration; sea-level rise: coastal development). Communication models that involve the head (understanding of climate change), heart (hope through agency and efficacy), and hands (intentions to participate in community action) further engagement in climate change conversations. We explain the research behind our communication framework, enabling practitioners to extend this case study to their own work.
Electrochemical Characterization of Bronze Exposed to Outdoor Atmosphere
Authors: Otmačić Ćurković Helena , Mikić Dajana , Bera Luka , Kovačević Ema , Marcelja Marijana
Published: July 2021

The aim of this work was to examine corrosion behaviour of bare and artificial patinated bronzes during exposure to urban outdoor atmosphere. Studies were conducted on

copper and two different bronzes in order to evaluate the influence of substrate composition on patina composition and electrochemical behaviour. Additionally, two different patination methods were compared. Corrosion behaviour was examined using electrochemical impedance spectroscopy with gel-electrolyte electrochemical cell. The composition of patina was determined by ATR-FTIR spectroscopy. The obtained results showed that all studied artificial patinas initially decrease the corrosion resistance of copper and bronzes but in time their corrosion resistance improves, and even for certain combinations, artificial patina-bronze corrosion resistance is higher than that of naturally patinated bronze.
The Classification of Heart Murmurs: The Identification of Significant Time Domain Features
Authors: Cheng Wai Kit , Khairuddin Ismail Mohd , P.P. Abdul Majeed Anwar , Mohd Razman Mohd Azraai
Published: July 2021

Phonocardiogram (PCG) is a type of acoustic signal collected from the heartbeat sound. PCG signals collected in the form of wave files and collected type of heart sound with a specific period. The difficulty of the binomial class in supervised machine learning is the steps-by-steps workflow. The consideration and decision make for every part are importantly stated so that misclassification will not occur. For the heart murmurs classification, data extraction has highly cared for it as we might have fault data consisting of outside signals. Before classifying murmurs in binomial, it will involve multiple features for selection that can have a better classification of the heart murmurs. Nevertheless, since classification performance is vital to conclude the results, models are needed to compare the research's output. The main objective of this study is to classify the signal of the murmur via time-domain based EEG signals. In this study, significant time-domain features were identified to determine the best features by using different feature selection methods. It continues with the classification with different models to compete for the highest accuracy as the performance for murmur classification. A set of Michigan Heart Sound and Murmur database (MHSDB) was provided by the University of Michigan Health System with chosen signals listening with the bell of the stethoscope at the apex area by left decubitus posture of the subjects. The PCG signals are pre-processed by segmentation of three seconds, downsampling eight thousand Hz and normalized to -1, +1. Features are extracted into ten features: Root Mean Square, Variance, Standard Deviation, Maximum, Minimum, Median, Skewness, Shape Factor, Kurtosis, and Mean. Two cross-validation methods applied, such as data splitting and k-fold cross-validation, were used to measure this study's data. Chi-Square and ANOVA technique practice to identify the significant features to improve the classification performance. The classification learners are enrolled and compared by Ada Boost, Random Forest (RF) and Support Vector Machine (SVM). The datasets will separate into a ratio of 70:30 and 80:20 for training and testing data, respectively. The chi-Square selection method was the best features selection method and 80:20 data splitting with better performance than the 70:30 ratio. The best classification accuracy for the models significantly come by SVM with all the categories with 100% except 70:30 test on test data with 97.2% only.
Preparation of thermoplastic polyurethane-based biocomposites through injection molding: Effect of the filler type and content
Authors: Mengeloğlu Fatih , Çavuş Vedat
Published: July 2021

The effects of lignocellulosic filler type and filler loading levels were investigated relative to selected properties of thermoplastic polyurethane (TPU)-based composites. Teak wood (TK), rice husks (RH), and microcrystalline cellulose (MCC) were used as lignocellulosic fillers at 15 wt% and 30 wt% filler loading levels. Test specimens were manufactured using both extrusion and injection molding, except for abrasion resistance samples that were manufactured using a compression molding process. Density, tensile, flexural, and impact properties, and hardness and abrasion resistance values, of the specimens were determined. The composites’ morphology was studied using scanning electron microscopy analysis; results showed all filler types and filler loading levels were affected by the TPU’s density and mechanical properties. The TPU composites were successfully produced using TK, RH, and MCC as lignocellulosic fillers. Regardless of filler type, addition of 15% filler to TPU yielded excellent mechanical properties. With 30% MCC filler, composite properties increased due to their higher surface area, while properties of TK- and RH-containing specimens were, at 30%, reduced. There was a proportional correlation between hardness and modulus, with both increasing with a rising filler loading level. Abrasion resistance of TPU decreased with the presence of filler. Regardless of filler type, abrasion resistance continued to drop at higher filler loading levels. Scanning electron micrographs showed better MCC distribution in the TPU matrix.
Modelling of dewatering wood pulp in a screw press using statistical and multivariate analysis
Authors: El Idrissi Bouchaib , Loranger Éric , Lanouette Robert , Bousquet Jean Pierre , Martinez Mark
Published: July 2021

Statistical modeling of a screw press was established by using an experimental design based on the screw rotational speed, the pulp feed consistency, the pulp feed suspension freeness, the inlet pressure, and the counter-pressure at the discharge end. The statistical models showed that the screw press outputs for each pulp could be predicted. When including all data in a global model to predict the outputs of the press for any pulp, a global statistical model was found not to be efficient by using just the five fixed parameters. The solution to this problem was to use a multivariate analysis to include more parameters, mainly about the fiber characteristics (crowding factor, fiber length, fiber width, and fines content). By including these fiber properties, the differences between each pulp were more properly analyzed. The multivariate analysis predicted the press outsets very well in a global model by using eight parameters instead of five. The R2 values of the multivariate prediction model were all higher than 0.70 and had the goodness of prediction (Q2¬¬¬) higher than 0.60.
Cookies Internal Temperature Estimation Using IHCP Methodology
Authors: Eduardo Macías Ávila , Yaneth Aguilar Díaz
Published: July 2021

This work constitutes a continuation of previous work on determining the internal temperature of foods by applying inverse heat transfer problem solving techniques. In this research, a mathematical model of heat transfer applied to foods is developed whose central part heat transfer can be described in Cartesian coordinates. This model uses techniques established in the previous work. The technique is based on the adjustment of parameters involved in heat transfer, minimizing the sum of squared errors between the measured temperatures and those calculated by the mathematical model. This paper discusses how the precision of this method would be affected with respect to the measurement time of the surface temperature and the delay time of the measurement.
Timing of Supplemental Nutrition Assistance Program Benefits and Families’ Home Food Environments
Authors: You Susan , Ansah Rosemary , Mullins Alexa , Johnson Sara B. , Perin Jamie , Flessa Sarah J. , Thornton Rachel L.J.
Published: July 2021

BACKGROUND AND OBJECTIVES

Supplemental Nutrition Assistance Program (SNAP) benefits are designed to buffer families from food insecurity, but studies suggest that most benefits are used by midmonth. In this study, we examined whether the home food environment varies across the SNAP benefits cycle among participating families .

METHODS

Participants in this mixed-methods study were 30 SNAP participants who were primary caregivers of a child ages 4–10 years. The home food environment was measured 1 week before SNAP benefit replenishment and again within 1 week after replenishment by using the Home Food Inventory. Household food insecurity was assessed by using the US Department of Agriculture Household Food Security Survey. Wilcoxon rank tests were used to evaluate changes in median Home Food Inventory subscales and food insecurity pre- to post-replenishment. Qualitative interviews with participating caregivers were conducted to explore contextual factors influencing the home food environment across the benefits cycle.

RESULTS

Participants had significantly fewer types of vegetables (median: 7.0 vs 8.5, median difference 1.73, 95% confidence interval: 0.5–2.5, P = .03) and higher food insecurity pre- versus post-replenishment (median: 4.0 vs 2.0, median difference 1, 95% confidence interval: 0.1–1.5, P = .03). Caregivers described employing a variety of intentional strategies to reduce cyclic variation in food availability.

CONCLUSIONS

Findings suggest that there is relatively limited cyclic variation in the home food environment among families participating in SNAP. This may be explained by a number of assistance programs and behavioral strategies caregivers used to make food last and buffer against scarcity. Future research should evaluate the relationship between the degree of home food environment changes and child health outcomes.
Differences in Lifetime Earning Potential Between Pediatric and Adult Physicians
Authors: Catenaccio Eva , Rochlin Jonathan M. , Simon Harold K.
Published: July 2021

OBJECTIVES

Compare lifetime earning potential between academic pediatric and adult medicine generalists and subspecialists. Evaluate the effect of decreasing the length of training for pediatric subspecialties whose length of training is longer than that for the adult medicine counterpart.

METHODS

Using compensation and debt data from national physician surveys for 2019–2020, we estimated and compared the lifetime earning potential for academic pediatric and adult physicians.

RESULTS

Lifetime earning potential was higher for adult physicians than for pediatric physicians across all comparable areas of both general and subspecialty academic practice. The lifetime earning potentials for adult physicians averaged 25% more, or $1.2 million higher, than those of the corresponding pediatric physicians. These differences predominantly were not attributable to unequal training length: when we modeled a shortened length of training for pediatric subspecialists, lifetime earning potential for adult subspecialists still averaged 19% more than that for pediatric subspecialists. For both pediatric and adult medicine, the primarily inpatient, procedure-oriented subspecialties had higher lifetime earning potential than the outpatient, less procedure-oriented subspecialties.

CONCLUSIONS

Wide differences in lifetime earning potential between pediatric and adult physicians reflected lower compensation in pediatrics, rather than any differences in training length. Inpatient-based, more procedure-oriented subspecialties had higher lifetime earning potential than outpatient-based, less procedure-oriented subspecialties. Interventions that improve the lifetime earning potential of general pediatrics and the pediatric subspecialties, as well as the less procedure-oriented subspecialties across both pediatric and adult medicine, have the potential to impact both clinical practice and access to care.
Conhecimento dos alunos do IFSul – Câmpus Bagé sobre informações contidas em rótulos de alimentos
Authors: Krumreich Fernanda , Muniz Daniane , Duarte Jayne , Meister Meira Stela Maris
Published: July 2021

O objetivo deste trabalho foi analisar o conhecimento dos alunos do Instituto Federal Sul-rio-grandense (IFSul) Câmpus Bagé a respeito das informações contidas nos rótulos dos alimentos e na informação nutricional através da aplicação de um questionário. A informação mais procurada pelos 79 alunos entrevistados nos rótulos de alimentos foi a marca comercial do produto. Já 32,9% não tem o hábito de olhar a informação nutricional, apesar de afirmarem compreendê-la. A observação da presença de glúten ou lactose foi realizada apenas por pessoas consideradas intolerantes ou alérgicas. Sobre alimentos light e diet e aditivos alimentares, a maioria dos entrevistados afirma saber a diferença entre light e diet e desconhecer o que são aditivos alimentares. Em relação às melhorias para os rótulos de alimentos, 21,5% dos entrevistados não souberam opinar e 13% consideraram as informações já contidas no rótulo, suficientes. Apesar de os alunos entrevistados afirmarem ter conhecimento em relação ao entendimento e uso das informações dos rótulos e da informação nutricional, não a utilizam para fazer escolhas conscientes, seguras, informadas e acertadas em relação à manutenção da saúde.
Palavras-chave: Rotulagem de alimentos; informação nutricional; consumidores; questionário.
Burnout
Authors: George Reena
Published: July 2021

Old Easter lilies, leaves wilting, when all around grass gleams, palms dapple, trees fruit.One morn,they were shorn, chopped, bruised, green things, burnt out.
“How will they survive?” I asked the gardener. “The bread-winner leaves cannot work.”
“The bulbs will grow,” He said.“Can bulbs grow without the leaves that fed them?”“The quiet womb of Mother Earth and safe sure arms of Father Heaven have food enough,” He said.
Un-knowing, un-doing, just being,seasons passedin moons and stars.Then a brave shy flower, a babe in arms,heard the Light,smiled colors bright, and Christmas dawnedon Easter morn.
ANALYSIS OF METHODS OF RECONSTRUCTION AND RENEWAL OF THE FOUNDATIONS OF HIGHWAY BRIDGES TAKING INTO ACCOUNT THE EXPERIENCE OF MILITARY CONFLICTS
Authors: OSTAPENKO I. S.
Published: July 2021

The purpose of the work is to analyze the modern domestic and foreign practice of extending the life of railway and road bridges as part of the problematic state of the transport and road complex, taking into account the impact on the quality condition of these objects of various factors and operating conditions due to their renewal and reconstruction. Methodology. The problematic issues of maintenance and operation of railway and road bridges in modern conditions are highlighted. Comprehensive measures aimed at extending the lifetime of these transport infrastructure objects through major repairs and reconstructions have been identified. On the basis of the analysis, conclusions were drawn about the need to improve the methods of strengthening the foundations of bridges during the renewal and reconstruction. Findings. Generalization of the modern foreign and domestic methods of strengthening the foundations of bridges provided the possibility of researching the most effective, cost-effective and easy-to-perform structures. Four directions of development of foundation strengthening are proposed: 1) increasing the area of support for shallow foundations on natural foundations; 2) arrangement of additional pile foundations with combining them into a common structural system with existing foundations and the construction of additional supports; 3) strengthening the existing pile foundations by changing the bearing capacity of the bases; 4) arrangement of other structural elements to ensure the reinforcement of the existing foundations of bridges. Originality. It consists in setting the task of strengthening the foundations of highway bridges during the renewal or reconstruction. Practical value. Based on the results of the analysis, we can recommend the most economically justified and quickly implemented methods of strengthening the foundations of bridges for design decisions in the implementation of state programs for the construction and development of the transport and road complex of Ukraine and in modern world practice.
Assessment of zinc solubilization potential of zinc-resistant Pseudomonas oleovorans strain ZSB13 isolated from contaminated soil
Authors: Rehman H. F. , Ashraf A. , Muzammil S. , Siddique M. H. , Ali T.
Published: July 2021

Abstract Zinc is an essential micronutrient that is required for optimum plant growth. It is present in soil in insoluble forms. Bacterial solubilization of soil unavailable form of Zn into available form, is an emerging approach to alleviate the Zn deficiency for plants and human beings. Zinc solubilizing bacteria (ZSB) could be a substitute for chemical Zn fertilizer. The present study aimed to isolate and characterize bacterial species from the contaminated soil and evaluate their Zn solubilizing potential. Zn resistant bacteria were isolated and evaluated for their MIC against Zn. Among the 13 isolated bacterial strains ZSB13 showed maximum MIC value upto 30mM/L. The bacterial strain with the highest resistance against Zn was selected for further analysis. Molecular characterization of ZSB13 was performed by 16S rRNA gene amplification which confirmed it as Pseudomonas oleovorans. Zn solubilization was determined through plate assay and broth medium. Four insoluble salts (zinc oxide (ZnO), zinc carbonate (ZnCO3), zinc sulphite (ZnS) and zinc phosphate (Zn3(PO4)2) were used for solubilization assay. Our results shows 11 mm clear halo zone on agar plates amended with ZnO. Likewise, ZSB13 showed significant release of Zn in broth amended with ZnCO3 (17 and 16.8 ppm) and ZnO (18.2 ppm). Furthermore, Zn resistance genes czcD was also enriched in ZSB13. In our study, bacterial strain comprising Zn solubilization potential has been isolated that could be further used for the growth enhancement of crops.
Historical review on the type locality of Knodus victoriae (Steindachner 1907) (Teleostei: Characidae) and Loricaria parnahybae Steindachner 1907 (Teleostei: Loricariidae)
Authors: Aguiar Rayane Gonçalves , Guimarães Erick Cristofore , Carvalho-Costa Luis Fernando , Ottoni Felipe Polivanov
Published: July 2021

Abstract: Based on the information and evidence on the zoological expedition led by the senior Austrian zoologist Franz Steindachner in 1903, the examination of original species descriptions using material collected in this expedition, the scientific literature on this expedition, examination of specimens of Knodus victoriae, and the consultation of State decrees modifying the name of localities and municipalities, we propose herein updated and accurate type localities for Knodus victoriae and Loricaria parnahybae. The accurate type locality for both species is at the mouth of a stream that flows into the Parnaiba River, Alto Parnaíba municipality in the State of Maranhão, upper Parnaiba River basin, northeastern Brazil. This update in the type locality aims to avoid doubts and confusion that hinder biogeographic and taxonomic studies.
A Física de um Desinfector com Radiação UV–C
Authors: Pessôa M. A. S. , Silva F. M. e , Lima Jr. M. P. , Galhardo G. , Olyntho P. H. M. , Neves A. A. R.
Published: July 2021

Neste artigo, discutimos a física envolvendo uma câmara de radiação ultravioleta–C (UV–C) utilizada para desinfecção de superfícies e objetos, no contexto da pandemia de COVID-19. Quando exposto à radiação UV–C, o RNA viral muda sua estrutura molecular num processo causado por uma realocação nas bases nitrogenadas, inativando o vírus e impedindo sua reprodução. Nós propomos a construção de uma câmara UV–C utilizando materiais acessíveis à população, com recursos de segurança. Também discutimos o processo de design na determinação da distância e tempo de exposição necessários para a dose de UV–C apropriada. Fatores teóricos que deixam o problema mais realista considerando-se a geometria do sistema também são utilizados. Experimentalmente, a lâmpada utilizada para o protótipo foi testada, obtendo-se uma potência na faixa do UV–C de Puv = 171μ W, após correções. Os tempos de exposição foram então definidos, e variaram de 20–90 minutos, considerando-se distâncias de 5–36 cm dos objetos à lâmpada.
Representation of agriculture in water governance in São Paulo
Authors: Martins Rodrigo Constante , Arbarotti Alexsandro Elias , Campregher Raiza
Published: July 2021

Abstract The water resources management model in the state of São Paulo is characterized by the participation of water users from different sectors of the economy within the ambit of River Basin Committees and other organizations of the water management system. The purpose of this article is to present a survey and systematization of the performance of representatives of São Paulo’s agricultural sector in this decentralized and participatory system of water governance. To this end, this article recreates the profile of this sectoral representation in the State Water Resources Council and in the Committees for rural areas with strong agricultural dynamics in the state. The findings of this study reveal significant political and propositional differences between São Paulo’s agriculture and agroindustry sectors. Such differences have to do with the structure and capillarity of the entities that represent these sectors, as well as their divergent concept of management.