bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutritional habits according to age and BMI of 6–17-year-old children from the urban municipality in Poland
Authors: Basiak-Rasała Alicja , Górna Sara , Krajewska Joanna , Kolator Mateusz , Pazdro-Zastawny Katarzyna , Basiak Aleksander , Zatoński Tomasz
Published: May 2022

Background

Balanced nutrition is crucial for adolescent’s proper physical and mental development. Dietary habits change significantly with a child’s development. Along with increasing age and the shift towards adolescence, unhealthy diet-related habits become more common. The objective of the survey study was to determine the differences in nutritional habits between children and adolescents according to their age and body mass index (BMI).

Methods

“Let’s get the kids moving” campaign (pol. “Uruchamiamy dzieciaki”) was launched in 2016. Within the campaign, the survey study was conducted in 2913 participants between 6 and 17 years old from primary and junior high schools in Wroclaw (Poland). The survey was anonymous, and its supplement was voluntary. Participants were divided into age groups. The study group of 2913 consisted of 29.8% of 6–9-year-olds, 32.7% of 10–12-year-olds, and 37.5% of 13–17-year-olds. Body mass index (BMI) was calculated and further interpreted as a BMI z-scores depending on children’s age and gender.

Results

A total of 19.3% of participants consumed 3 meals a day or less. Children from the oldest age group (13–17) consumed statistically significantly fewer meals per day than younger children (p < 0.001). Children from the oldest age group (13–17) consumed breakfast statistically less often than children of age group 10–12 years (75.0% vs. 83.6%; p < 0.001) and children of age group 6–9 years (75.0% vs. 84.0%; p < 0.001). Severely thin children consumed breakfast significantly more often than overweight (85.8% vs. 76.3%; p = 0.004) and children with obesity (85.8% vs. 75.9%; p = 0.021). Children with obesity consumed vegetables significantly less often than severely thin (p < 0.008), thin (p < 0.001), and children with normal body weight (p < 0.007). The oldest children (13–17 years) consumed Coca-Cola and SSB (p < 0.001) and fruit-flavored beverages (p < 0.05) significantly more often than children from other age groups. Boys consumed carbonated beverages with added sugar significantly more often than girls (p < 0.01).

Conclusions

Unhealthy diet-related behaviors in children and adolescents may promote overweight and obesity and should be targeted in health promotion programs. Special attention should be paid to 13–17-year-olds, as adolescents from this group made more unhealthy choices than younger children.
Long term outcomes of chronic pain patients attending a publicly funded community-based interdisciplinary pain program in the Greater Toronto area: results of a practice-based audit
Authors: Mailis Angela , Deshpande Amol , Lakha S. Fatima
Published: May 2022

Background

Chronic pain management multi/interdisciplinary programs attempt to address all elements of the biopsychosocial model. The primary objective of this retrospective study (based on practice-based audit) was to determine the effectiveness of a patient-centered, comprehensive and intense interdisciplinary pain management program in a publicly funded community-based pain clinic in the Greater Toronto Area.

Method

This retrospective longitudinal study was conducted on 218 carefully selected sequential chronic pain patients, with 158 completing a 3–4-month interdisciplinary program between January 2016 and December 2018. Data collected upon exit, at 6 months and 12 months post-discharge included demographic information, pain characteristics, emotional/functional status obtained by validated instruments and global impression of change (GIC). Additionally, social health outcomes (return to work or school) were retrieved through retrospective chart review. Means of pre-and post-program variables were compared to assess changes of each patient’s “journey”.

Results

Physical and mental/ emotional health outcomes at exit, 6 months and 12 months post-discharge, showed initial and sustained, statistically and clinically significant improvement from pre-treatment levels, with GIC (much/very much improved) reported as 77%, 58% and 76%, respectively. Additionally, a substantial positive change in social health outcomes was noted particularly in patients on disability (29%), part time workers gaining full time employment (55%), and students (71%) who improved their level of schooling.

Conclusion

The study showed that careful patient selection in a community-based publicly funded interdisciplinary pain management program can produce significant improvement in pain, physical, mental/emotional health and social function, with sustained long-term outcomes.
Oral Glucose Tolerance Test Measures of First-phase Insulin Response and Their Predictive Ability for Type 1 Diabetes
Authors: Baidal David A , Warnock Megan , Xu Ping , Geyer Susan , Marks Jennifer B , Moran Antoinette , Sosenko Jay , Evans-Molina Carmella
Published: May 2022

Context

Decreased first-phase insulin response (FPIR) during intravenous glucose tolerance testing (IVGTT) is an early indicator of β-cell dysfunction and predictor of type 1 diabetes (T1D).

Objective

Assess whether oral glucose tolerance test (OGTT) measures could serve as FPIR alternatives in their ability to predict T1D in autoantibody positive (Aab+) subjects.

Design

OGTT and IVGTT were performed within 30 days of each other. Eleven OGTT variables were evaluated for (1) correlation with FPIR and (2) T1D prediction.

Setting

Type 1 Diabetes TrialNet “Oral Insulin for Prevention of Diabetes in Relatives at Risk for T1D” (TN-07) and Diabetes Prevention Trial-Type 1 Diabetes (DPT-1) studies clinical sites.

Patients

TN-07 (n = 292; age 9.4 ± 6.1 years) and DPT-1 (n = 194; age 15.1 ± 10.0 years) Aab + relatives of T1D individuals.

Main outcome measures

(1) Correlation coefficients of OGTT measures with FPIR and (2) T1D prediction at 2 years using area under receiver operating characteristic (ROCAUC) curves.

Results

Index60 showed the strongest correlation in DPT-1 (r = -0.562) but was weaker in TN-07 (r = -0.378). C-peptide index consistently showed good correlation with FPIR across studies (TN-07, r = 0.583; DPT-1, r = 0.544; P < 0.0001). Index60 and C-peptide index had the highest ROCAUCs for T1D prediction (0.778 vs 0.717 in TN-07 and 0.763 vs 0.721 in DPT-1, respectively; P = NS), followed by FPIR (0.707 in TN-07; 0.628 in DPT-1).

Conclusions

C-peptide index was the strongest measure to correlate with FPIR in both studies. Index60 and C-peptide index had the highest predictive accuracy for T1D and were comparable. OGTTs could be considered instead of IVGTTs for subject stratification in T1D prevention trials.
Symptoms and Glycemic Control in Young People With Type 1 Diabetes Following SARS-CoV-2 Infection: An Observational Study
Authors: Nimri Revital , Rachmiel Marianna , Yackobovitch-Gavan Michal , Brener Avivit , de Vries Liat , Fisch Shvalb Naama , Lazar Liora , Oren Asaf , Jacobi-Polishook Talia , Shefer Averbuch Noa , Tenenbaum Ariel , Mel Eran , Krepel Volsky Sari , Mouler Marie , Demol Sharon , Shalitin Shlomit , Bello Rachel , Phillip Moshe , Lebenthal Yael
Published: May 2022

Context

Data is needed regarding the effect of SARS-CoV-19 infection on young people with established type 1 diabetes. Identifying the disease outcomes, short and long-term sequelae may help to establish an evidence-based prevention and education policy for sick days management and DKA prevention.

Objective

This work aims to describe clinical manifestations of SARS-CoV-2 infection in children, adolescents, and young adults with established type 1 diabetes (T1D) and explore the effects of COVID-19 on glycemic control and disease course.

Methods

An observational study was conducted at 3 pediatric diabetes clinics in Israel between mid-March 2020 and mid-March 2021. Included were young people with established T1D, age younger than 30 years, who tested positive for SARS-CoV-2 (quantitative real-time polymerase chain reaction). Data were collected from medical files, diabetes devices, and COVID-19 questionnaire. Outcome measures were analyzed by the presence/absence of clinical symptoms (symptomatic/asymptomatic) and by age group (pediatric, < 19 years/young adults, 19-30 years).

Results

Of 132 patients, mean age 16.9 ± 5.3years, with COVID-19–confirmed infection, 103 (78%) had related symptoms; the most common were headaches, fatigue, fever, and loss of sense of smell. All had a mild disease course, but 4 required hospitalization and 2 cases were directly related to COVID-19 infection (pleuropneumonia in a patient with immunodeficiency syndrome, 1 case of diabetic ketoacidosis). Logistic regression analysis showed that age (odds ratio [OR] = 1.11; 95% CI, 1.01-1.23; P = .033), elevated glucose levels (OR = 5.23; 95% CI, 1.12-24.41; P = .035), and comorbidities (OR = 8.21; 95% CI, 1.00-67.51; P = .050) were positively associated with symptomatic infection. Persistent symptoms occurred in 16.5% of the cohort over a median of 6.7 months; age (OR = 1.14; 95% CI, 1.01-1.29; P = .030) and elevated glucose levels (OR = 3.42; 95% CI, 1.12-10.40; P = .031) were positively associated with persistent symptoms. Usually, no change was reported in glucose levels (64%) except for a temporary deterioration in glycemic control during the short infection period.

Conclusion

Young people with established T1D experience mild COVID-19 infection. Elevated glucose levels during COVID-19 infection and older age were associated with prolonged disease course.
Comparison of Hour-to-Hour and Hour-Block Energy Trading for Networked Microgrids to Optimize Profits
Authors: Vankudoth Lokesh , Badar Altaf Q. H.
Published: May 2022

Networked Microgrids are a concept that emerged as a result of growing microgrid deployments in the distribution network. Microgrids in close geographical or electrical proximity are coupled to build networked microgrids. Networked microgrids offer coordinated energy management, as well as interaction and energy exchange across microgrids. This increases the reliability of microgrids and lowers their running costs. Hour-to-hour, depending on generation and load profiles, Time-of-Use pricing, microgrids can manage energy inside the microgrid and participate in energy trading with linked microgrids to reduce costs. Demand response is also utilized in energy management to achieve the above objectives. In contrast to the preceding hour-to-hour strategy, a unique hour-block-based demand response program in Networked Microgrids is suggested in this paper. In this paper, in contrast, to the above hour-to-hour approach a novel hour block-based demand response program in Networked Microgrids is proposed. Each hour block is formed based on generation and load imbalance, the role of Microgrids and the Time-of-Use tariff system. Both techniques are evaluated in terms of time and complexity using the Particle Swarm Optimization method. The economic benefits of individual microgrids and networked microgrids are also compared.
An Environment Friendly Energy-Saving Dispatch Using Mixed Integer Linear Programming Relaxation in the Smart Grid with Renewable Energy Sources
Authors: Pandey Yudhishthir , Hasan Naimul , Husain Mohammed Aslam , Khan Ahmad Neyaz , Bakhsh Farhad Ilahi , Minai Ahmad Faiz , Tabrez Md
Published: May 2022

Electrical energy demand has risen over the world which results in developmentof smart grid. Smart grid has identified the areas that requiresimprovement. Because of the focus on cost-effective operation as well asenvironmental concerns in the electrical power system, the complexity ofthe optimization function has increased. In this study, a new energy-saving dispatch model is developed, which takes into account renewable energysources in the smart grid as well as dynamic generation-load interaction.Moreover, the active demand response idea is employed for interruptibleloads during peak demand. During off-peak load periods and compensatingloads, the proposed energy-saving dispatch system operates on a bi-leveldispatch system. Lower level dispatch works with four dispatch functionssuch as interruptible load cost, compensation load cost, renewable energysource cost, and emission saving cost. Whereas, upper level dispatch dealswith cost functions for operation and emission. Renewable energy sources arerepresented as a generating unit as well as a load based on usage in this work.Linear programming relaxation and mixed integer linear programming relaxationmethodologies are used to solve the constrained optimization problem.The outcomes of the experiments were compared with existing methodologiessuch as the classic NSGA-II and the improved NSGA-II. Furthermore,the algorithm’s time complexity was examined. The proposed solution hasbeen implemented using the IEEE-30 bus standard. The performance resultsdemonstrate considerable reductions in operating costs as well as reductionsin emissions.
The Optimal Placement of Electric Vehicle Fast Charging Stations in the Electrical Distribution System with Randomly Placed Solar Power Distributed Generations
Authors: Ahmad Fareed , Iqbal Atif , Ashraf Imtiaz , Marzband Mousa , Khan Irfan
Published: May 2022

The growing use of electric vehicles (EVs) in today’s transport sector isgradually reducing the use of petroleum-based vehicles. However, as EVpenetration grows, the EV’s demand influences distribution network parameterssuch as power loss, voltage profile. Therefore, an improved bald eaglesearch (IBES) algorithm is suggested for the optimal placement of FCSsinto the distribution network with high penetration of randomly distributedsolar power generation (SPDG). This study suggests a two-stage approachfor placing FCSs. The charging station investor decision index (CSIDI) was introduced in the first stage, taking into account the land cost index (LCI)and the electric vehicle population index (EVPI). The CSIDI was developedto decrease land costs while increasing EV population for FCS installation.In the next one, an optimization problem is constructed to minimize totalactive power loss while taking distribution system operator (DSO) constraintsinto consideration. The IEEE-34 bus distribution system is used as theproposed network. The simulation is carried out in MATLAB to integratethe EVCSs in three cases in the distribution network with SPDGs randomlyplaced. Therefore, The IBES found the best optimal positions with a powerloss of 198.43 kW. When compared to the PSO technique, the IBES techniquehas a reduced average power loss of 2.02%.
Improving Efficiencies of Ratio- and Product-type Estimators for Estimating Population Mean for Time-based Survey
Authors: Chhaparwal Priyanka , Kumar Sanjay
Published: May 2022

Statisticians often use auxiliary information at an estimation stage to increase efficiencies of estimators. In this article, we suggest modified ratio- and product-type estimators utilizing the known value of the coefficient of variation of the auxiliary variable for a time-based survey. Further, to excel the performance of the suggested estimators, we utilize information from the past surveys along with the current surveys through hybrid exponentially weighted average. We obtain expressions for biases and mean square errors of the suggested estimators. The conditions, under which the suggested estimators have less mean square errors than that of other existing estimators, are also obtained. The results obtained through an empirical analysis examine the use of information from past surveys along with current surveys and show that the mean square errors and biases of the suggested estimators are less than that of the existing estimators. For example: for a sample size 5, mean square error and bias of the suggested ratio-type estimator are (0.0414,0.0065) which are less than (0.5581,0.0944) of the existing Cochran (1940) estimator, (0.4788,0.0758), of Sisodia and Dwivedi (1981) estimator and (0.0482,0.0082) of Muhammad Noor-ul-Amin (2020) estimator. Similarly, mean square error and bias of the suggested product- type estimator are (0.0025,−0.0006) which are less than (0.0612,−0.0096) of the existing Murthy (1964) estimator, (0.0286,−0.0071), of Pandey and Dubey (1988) estimator and (0.0053,−0.0008) of Muhammad Noor-ul-Amin (2020) estimator.
An overview of hydrophobic treatments and their application with Internal Wall Insulation
Authors: Cambray Toby , Marincioni Valentina , Altamirano Hector
Published: May 2022

Hydrophobic (or water-repellent) treatments have been proposed to mitigate moisture risks associated with Internal Wall Insulation when applied to solid masonry walls. This can reduce risks associated with moisture accumulation within the structure such as mould growth or the deterioration of joist ends and other embedded timber. However, such treatments slow down drying processes, and therefore may result in a net increase in moisture if the treatment is bypassed by e.g. cracks. Furthermore, such treatments have been linked with damage to external masonry surfaces. Freeze-thaw and salt crystallisation are the two main causes. Hygrothermal simulations may give some indication of risks but techniques to assess surface damage are either simplistic, impractical outside of the research environment, or both.
Modelling and Performance Evaluation of 18w PEM Fuel Cell Considering H2 Pressure Variations
Authors: Bhoopal Neerudi , Rao Dokku Sivanaga Malleswara , Sireesha Nagineni Venkata , Kasireddy Idamakanti , Gatla Ranjith Kumar , Kumar Devineni Gireesh
Published: May 2022

The chemical energy of a hydrogen-oxygen reaction is converted directly into dc electrical energy by fuel cells (FC). PEMFCs (Proton Exchange Membrane Fuel Cells) are a feasible alternative for electrical transportation and stationary applications. This paper presented a PEMFC modelling approach using Artificial Intelligence. The main objective of this research is to build a model of an 18w Polymer Electrolyte Membrane (PEM) fuel cell and test its performance under different hydrogen pressure conditions. The physical model of the 18W hydrogen fueled PEM fuel cell is designed and tested at BHEL R&D. Additionally, a method for predicting a PEMFC's operating temperature using the voltage and current measures is suggested and successfully tested. However, the proposed technique is validated using experimental data from an 18W fuel cell. The analytical data and testing procedures required for determining the parameter values used in the proposed model are specified.
Synthesis and Applications of Biopolymer /FeO Nanocomposites: A Review
Authors: Warkar Sudhir G.
Published: May 2022

Magnetic oxide nanoparticles have engaged most consideration due to their rare character, such as easy separation, surface-to- volume ratio, paramagnetic and high surface area. Natural biopolymers, namely, (Chitosan, Guar-Gum, Tamarind, Alginate, Dextran, Pectin) have posed as an incredible host for the preparation of magnetic nanoparticles. Biopolymer based magnetic nanocomposites have been fabricated from long time using method like co-precipitations, green synthesis, in-situ, hydrothermal and wet chemical method. Properties of biopolymer magnetic nanocomposites draw attention to the researchers towards fabricating at the nano level for various applications like as adsorptions inorganic metal, organic impurity, targeted drug-delivery, bio-sensing, catalysis activity, antimicrobial activity, antifungal activity, antioxidant activity, anti-cancer activity, energy, environmental remediation, waste water treatment and textiles. This review is designed to report very firstly reported biopolymer magnetic nanoparticles (BMNPs) in last ten years and attractive approach in various applications.
Analysis of Foot-Ground Interaction for Assessment of Gait Using Lab View
Authors: J Samson Isaac J, Dhiviyalakshmi , L Anantha Christu Raj , P Sreepadmini , R Siva Sakthi , A Siva Sakthi
Published: May 2022

Injuries caused by falls are common among athletes. The field of sports mechanics and training are moving towards implementing green technology to evaluate the performance and training of the athletes. There is a need to understand the gait pattern of an individual for better understanding and planning. Gait analyses performed within a laboratory imposes restriction over an individual’s performance, which can influence the gait pattern intended to study. A shoe-integrated sensor system provides the freedom to move the subject freely, while at the same time provides information related to the gait pattern and fall events occur. MEMS sensors integrated shoes are developed to study the gait pattern for wellness monitoring among elders. The fall is detected by comparing the amount of the pressure distribution in the respective sensors with the accelerometer placed around the ankle. In this work, the presence of the abnormality in the gait pattern and the abnormal point are analysed. A shoe system with sensor design and interface with LabVIEW are developed. In case 1, the heel pressure is 35mV, the toe pressure is 9.2mV, acceleration value is 1.3mV and fall is no fall.
Synthesis of Honeycomb-Shaped LiNi0.5Mn0.5O2 Using a Sol-Gel Method with Polymethylmethacrylate (PMMA) and Organic Surfactant
Authors: Lee Seon-Jin , Kim Hea-in , Park Eui-Jeong , Son Jong-Tae
Published: May 2022

Layered-structural LiNi0.5Mn0.5O2 has high discharge capacity, abundant availability, enhanced chemical stability, convenient environmental benignancy, and low cost. However, LiNi0.5Mn0.5O2 suffers from poor intrinsic rate capability due to its poor ionic conductivity (2.54 × 10-7 S/cm) and poor cycle stability owing to the volume change of the cathode materials during cycling. To address this issue, honeycomb-shaped LiNi0.5Mn0.5O2 was developed for lithium-ion batteries using a sol-gel method with spherical polymethylmethacrylate (PMMA) particles. PMMA particles provide spherical voids in LiNi0.5Mn0.5O2 cathode materials due to their relatively low decomposition temperature (< 350 °C). Honeycomb-shaped LiNi0.5Mn0.5O2 has a higher surface area (2.63 m2/g) than the LiNi0.5Mn0.5O2 (2.00 m2/g) produced by conventional sol-gel method. The initial discharge capacities of conventional nano LiNi0.5Mn0.5O2 and honeycomb-shaped LiNi0.5Mn0.5O2 are 151.9 mAh g-1 and 200.4 mAh g-1, respectively at 0.1 C. After 50 cycles at 1 C, honeycomb-shaped LiNi0.5Mn0.5O2 has a larger capacity retention than conventional nano LiNi0.5Mn0.5O2, measuring 67.9% and 58.8%, respectively. The superior electrochemical performance of honeycomb-shaped LiNi0.5Mn0.5O2 increases the effective surface area for Li-ion diffusion, leading to better rate capability, and buffers the volume change during Li+ion insertion/extraction, improving the cycling stability.
Sodium Nitrate As a Corrosion Inhibitor of Carbon Steel in Various Concentrations of Hydrochloric Acid Solution
Authors: Jafar Saad A. , Aabid Ahmad A. , Razzaq Ghassan Hassan Abdul , Humadi Jasim I.
Published: May 2022

In the chemical and petroleum industries, metals are used in over 90% of construction units. Iron and steel are widely used metals in the fabrication and manufacturing of petroleum field operating platforms. The exposures of metals to the effect of bases or acids in the various industries can be severe to the metals specifications and thus result in suddenly failure of materials in service. So that, the need to investigate the protection of metals when exposed to various environments, as this is a very important factor in the selection of material that determines the service life of it. In the present study, the effect of various concentrations ranging from (25 to 100 mg/l) of sodium nitrate was studied in inhibiting the corrosion of carbon steel placed in different concentrations of hydrochloric acid solution (1 M, 2 M, and 3 M), the results showed that the concentration of (75 mg/l) of sodium nitrate achieved the best inhibition of the acid used in all the concentrations used, as it reduced the corrosion rate by 48.91% for a concentration of 1 M, 39.38% for a concentration of 2 M, and 35.33% for a concentration of 3 M.
Investigation Photoluminescence Property of ZnO / PANI Nanocomposite Synthesized in​ [EtOHMIM+] [HSO4-] Ionic Liquid and CTAB Surfactant
Authors: Benabdellah A. , Negadi K. , Chaker Y. , Fettouhi B. , Belarbi H. , Hatti M.
Published: May 2022

In the present work, ZnO nanoparticles (NPs) were prepared using hydrothermal method with Trimethyl Ammonium Bromide (CTAB) as surfactant in 1- (hydroxyethyl)-3- methylimidazolium sulfate [EtOHMIM+] [HSO-] ionic liquid (IL). ZnO / PANI nanocomposite was prepared via in situ polymerization. The structures of the modified ZnO particles were characterized by X-ray diffraction, Raman spectroscopy and, scanning electron microscopy (SEM). The optical properties of (ZnO / PANI) nanocomposite were examined by photoluminescence (PL) analysis. XRD and, Raman analysis confirmed that pure ZnO (NPs) synthesized with (CTAB) in [EtOHMIM+] [HSO-] IL were formed. The addition of (CTAB) and [EtOHMIM+] [HSO-] IL does not change the ZnO phase but reduces the particle size of ZnO and converts shallow defects to deep defects. The SEM images of the ZnO / PANI nanocomposite showed the formation of hexagonal wurtzite ZnO (NPs) embedded in polyaniline matrix. The PL intensity of the ZnO / PANI nanocomposite is improved as compared to pure ZnO (NPs). This indicates that [EtOHMIM+] [HSO4-] IL may be acting as a dye, since it is constituted by an organic part, [EtOHMIM+]. This good performance indicates that the synthesised nanocompsite is promising material as photoanode in solar cells.
Jackfruit Peel Extract as Environmentally Safe Inhibitor for Carbon Steel Protection in Acidic Solution
Authors: Kusumaningrum Ira , Soenoko Rudy , SIswanto Eko , Gapsari Femiana
Published: May 2022

The addition of corrosion inhibitors into the acidic environment is an environmental modification to control the rate of corrosion. Organic compound inhibitors become an environmentally friendly alternative. In this study, research and analysis have been carried out on jackfruit peel extract as a corrosion inhibitor for AISI 1037 carbon steel protection in 1M HCl solution. Variation of inhibitor concentration is 200-3000 ppm. Corrosion rate measurements were performed by applying weight loss and potential polarization methods. The addition of inhibitor concentrations up to 1000 ppm increased the inhibitor efficiency up to 90.98%, but the efficiency decreased at concentrations of 2000 ppm and 3000 ppm. The adsorption inhibitors that occurred in this study was physical adsorption. It followed the Langmuir isothermal adsorption. The fungsional group of the film layer on the carbon steel surface indicated that the jack fruit peel extract compounds was adsorbed on the steel surface.
Evaluation of Antioxidant Activity by Electrochemical and Chemical Methods, Kinetics and Thermodynamic Parameters of Superoxide Anion Radical towards Cupressus sempervirens L. Extracts
Authors: Rahmani Zineb , Belfar Assia , Touahria Tatou , Bensaci Chayma , Rahmani Zehour , Dekmouche Messaouda , Saidi Mokhtar , Douadi Ali
Published: May 2022

For the first time in this report, we determined the antioxidative capacity of Cupressus sempervirens extracts by using two methods such as inhibition of superoxide anion (0∙−2) made by alkaline pyrogallol, and electrochemical generation of this radical. We have studied the O2/0∙−2 redox couple on the GC in DMF. We obtained well-resolved quasireversible and reproducible cyclic voltammograms for the O2/O∙−2 redox couple. A ipaipc value of 0.96 and ΔEp value of 160 mV for scan rates 0.1 V/s were obtained. In addition, the standard electrochemical rate constant k∘ is 2.31×10−3 cm s−1; all these characteristics clearly show that the system is quasi-reversible. Furthermore, we have used the cyclic voltammetric to study the antioxidant capacity of Cupressus sempervirens extracts. The thermodynamic feasibility of the radical scavenging by extracts was accounted in term of standard free energy ΔG∘, which ranged from -8.934 to 0.042 kJ/mol.
Towards the Design and Analysis of Multiplexer/Demultiplexer Using Quantum Dot Cellular Automata for Nano Systems
Authors: Khan Angshuman , Arya Rajeev
Published: May 2022

Quantum dot Cellular Automata (QCA) is a rapidly developing nanotechnology that offersultra-low energy loss, increased speed, and incredibly tiny area requirements. The two most important building blocks of QCA nano computing are the multiplexer and demultiplexer. The performance of new 2:1 multiplexer and 1:2 demultiplexer QCA layouts was investigated in this study. For a better performance study, two methodologies were used to measure energy loss, and alternative cost functions were explored. Total energy losses of 14.30 meV and 7.37 meV for the proposed multiplexer and demultiplexer, respectively, were detected using the software QDADesigner-E (QDE) in the Coherence vector simulation mode applying the Runge Kutta approximation technique. According to QCAPro, at the tunneling level 0.5EK and temperature 2K, the total energy loss of the multiplexer and the demultiplexer is 35.60 meV and 37.19 meV, respectively. Cost functions for both experimental items were also calculated in three different methods.
Improve Microbial Fuel Cell Efficiency Using Receding Horizon Predictive Control
Authors: Gao Jie , Gu Hai , Yang Yuwei , Yuan Ping , Poloei Hesam
Published: May 2022

One of the promising technologies in the field of clean and renewable energy is the microbial fuel cells, which in addition to generating electrical energy from the metabolism of microorganisms, can also be used to improve the environment in wastewater treatment. In fact, this paper designs an integrated control model that in the presence of uncertainty and unknown parameters can consider the effect of input variables for two-population in a chamber. In addition to maintaining closed loop stability, it has acceptable behavior in terms of time to reach steady state and reduce system error and provide satisfactory performance in terms of output energy. Lyapunov analysis ensures system stability and system control functions are demonstrated by MATLAB / Simulink simulations.
Study on Electrical Characteristics of Thin Flexible Crystalline Silicon Solar Cells
Authors: Chen Gong , Wang Yan , Xu Yang , Zhu Ying , Li Jieling , Wang Wei , Li Xuelian
Published: May 2022

Flexibility makes output voltage-current curve of thin crystalline silicon solar cell’s photovoltaic (PV) array stair-stepping and corresponding power-voltage curve possessing non-uniform illumination characteristics, so existing conventional PV array model is no more suitable and it is necessary to build a new mathematical model of PV array that is suitable for flexibility condition. Based on engineering model of PV array and combining with series-parallel connection of electric circuit, the PV array under flexibility is analyzed in detail and it is derived theoretically that the mathematical model of PV array under flexibility can be expressed by piecewis function.
Cerebral autoregulation across the menstrual cycle in eumenorrheic women
Authors: Korad Stephanie , Mündel Toby , Fan Jui‐Lin , Perry Blake G.
Published: May 2022

There is emerging evidence that ovarian hormones play a significant role in the lower stroke incidence observed in pre‐menopausal women compared with men. However, the role of ovarian hormones in cerebrovascular regulation remains to be elucidated. We examined the blood pressure‐cerebral blood flow relationship (cerebral autoregulation) across the menstrual cycle in eumenorrheic women (n = 12; mean ± SD: age, 31 ± 7 years). Participants completed sit‐to‐stand and Valsalva maneuvers (VM, mouth pressure of 40 mmHg for 15 s) during the early follicular (EF), late follicular (LF), and mid‐luteal (ML) menstrual cycle phases, confirmed by serum measurement of progesterone and 17β‐estradiol. Middle cerebral artery blood velocity (MCAv), arterial blood pressure and partial pressure of end‐tidal carbon dioxide were measured. Cerebral autoregulation was assessed by transfer function analysis during spontaneous blood pressure oscillations, rate of regulation (RoR) during sit‐to‐stand maneuvers, and Tieck’s autoregulatory index during VM phases II and IV (AI‐II and AI‐IV, respectively). Resting mean MCAv (MCAvmean), blood pressure, and cerebral autoregulation were unchanged across the menstrual cycle (all p > 0.12). RoR tended to be different (EF, 0.25 ± 0.06; LF; 0.19 ± 0.04; ML, 0.18 ± 0.12 sec−1; p = 0.07) and demonstrated a negative relationship with 17β‐estradiol (R2 = 0.26, p = 0.02). No changes in AI‐II (EF, 1.95 ± 1.20; LF, 1.67 ± 0.77 and ML, 1.20 ± 0.55) or AI‐IV (EF, 1.35 ± 0.21; LF, 1.27 ± 0.26 and ML, 1.20 ± 0.2) were observed (p = 0.25 and 0.37, respectively). Although, a significant interaction effect (p = 0.02) was observed for the VM MCAvmean response. These data indicate that the menstrual cycle has limited impact on cerebrovascular autoregulation, but individual differences should be considered.
A New True Triaxial Apparatus for Finite Deformation with a Novel Rigid–Flexible Loading Device
Authors: Xie Wen-Bo , Ye Guan-Lin , Zhang Qi , Chen Jin-Jian , Zhang Feng
Published: May 2022

This paper presents a new true triaxial apparatus with mixed boundaries for soft soils. A novel rigid–flexible loading device with four sliding rigid plates is designed. In the new loading device, the sliding block and the loading plate are separated, which allows the plates to be enclosed by a rubber membrane. This unique design can not only avoid the interference between adjacent plates and the corner effect, but also achieve a full π plane stress path. The friction between the sliding plates and specimen is reduced to a negligible level by using Teflon films together with lubricant. Paired sliding plates are connected precisely by a special transmission device and driven by a servo motor, which makes it possible to keep the specimen central, in either displacement control or load control modes. The new apparatus was used to investigate the mechanical properties of Shanghai Layer-4 clay under the three-dimensional loading condition. Typical test results are presented and discussed comprehensively. The influence of Lode angle on the stress–strain relation of the clay in finite deformation is investigated and the applicability of the new apparatus to soft soil testing is confirmed.
Thermodynamic Calculations and Heat Treatments on Phase Transformation Characteristics of 9Cr1Mo Steel
Authors: Liu Sheng , Hu Xinbin
Published: May 2022

9Cr1Mo steels are widely used for high-temperature applications in thermal power plants, owing to their relatively high strengths and low costs. In the present study, thermodynamic calculations of equilibrium and nonequilibrium transformations are carried out by JMatPro software. In the equilibrium condition, the austenite transforms to ferrite with saturated amount of M23C6 carbides ((Cr,Fe)23C6) at a temperature lower than 600°C. By contrast, austenite-martensite transformation accompanied by precipitation of a lesser amount of M23C6 carbides occurs lower than 340°C under a certain cooling rate during the nonequilibrium process. Meanwhile, an experimental investigation on the effect of various cooling rates after austenization on the microstructure and hardness of austenitized and tempered steel has been presented. The experimental results are close to the calculated ones. As the cooling rate after austenization increases, the ferrite transformation turns into martensite transformation, which could be verified by the variations of hardness, phase compositions, precipitation behaviors and grain boundary characteristics.
Joint decision on wooden pallet lease pricing and purchase volume under recycling and reusing mode in the Chinese market
Authors: Cai Jiali , Wu Jinzhuo , Wang Hui , Wu Tongtong
Published: May 2022

A closed-loop wooden pallet rental system was considered in this study, which involved a wooden pallet manufacturer, a wooden pallet leasing company, and several customers. To solve the joint optimization problem of pallet lease pricing and purchase volume under recycling and reusing mode, a mathematical model was constructed with the objective of maximizing the profit of pallet renters under deterministic and stochastic market demand. Meanwhile, comparative analyses were conducted on the optimal pricing, optimal order quantity, and expected profit under the two leasing modes of considering and not considering maintenance. On this basis, sensitivity analyses were performed on some parameters of the two modes. Results showed that pallet renters can adopt the maintenance strategy to increase profits by lowering the rental price appropriately regardless of the market demand. The wood pallet rental supply chain can be more efficient when the pallet residual value, recovery integrity rate, and utilization rate are higher and the out of stock cost and inventory holding cost are lower. Under the maintenance mode, a lower repairing price and higher reparability rate resulted in a more favorable maintenance mode.
An artificial neural network model for predicting mechanical strength of bamboo-wood composite based on layups configuration
Authors: Su Zihua , Jiang Zhilin , Liang Yi , Wang Bingzhen , Sun Jianping
Published: May 2022

The transportation application of the bamboo–wood composite container flooring (BWCCF) has increased considerably. However, materials would be destroyed in the process of common mechanical evaluation, resulting in a waste of resources. Therefore, this paper aims to design artificial neural network (ANN) models to predict mechanical strength of BWCCF. The modulus of rupture (MOR) and the modulus of elasticity (MOE) of BWCCF were predicted by ANN models based on layups configuration, including directions, densities, and thicknesses of 21-layer BWCCF in each layer. According to results, the mean absolute percentage errors (MAPE) and the correlation coefficient (R) were determined as 16.93% and 0.619 in prediction of MOR, and 10.10% and 0.709 in prediction of MOE, respectively. The results indicated that ANN can be applied to predict mechanical properties of BWCCF.
Shear performances of shallow notch-screw connections for timber-concrete composite (TCC) floors
Authors: Ben Qingguo , Dai Yongqing , Chen Sijian , Shi Benkai , Yang Huifeng
Published: May 2022

Shallow notch-screw connections, which showed potential superior slip moduli and load-carrying capacity compared with the traditional screwed connections and can be employed in the timber-concrete composite (TCC) floors were examined in this study. Eight groups of shallow notch-screw connections were designed to perform the push-out tests, in which the arrangement of screws, the heavy timber types, and the width of the shallow notch were considered. The depth of the notch was uniformly 15 mm. The vertical screws and the cross inclined screws were separately selected as the reinforcement for the shallow notch connections. The common heavy timber panels, including nail laminated timber (NLT), glulam, and cross laminated timber (CLT), were adopted. The width of the shallow notch tested included 100 and 200 mm. The experimental results showed that the shallow notch connections underwent ductile failure. The effects of testing factors on the shear strength, slip moduli, and ductility were discussed. The design proposals about the slip moduli of the shallow notches using each timber panel types were proposed, aiming to provide guidance for the application of the TCC floors with shallow notches.
Comparison of mechanical properties of 3D-printed and compression-molded wood-polylactic acid (PLA) composites
Authors: Narlıoğlu Nasır
Published: May 2022

Mechanical properties of materials obtained by compression-molding were compared with three-dimensional (3D) printed materials. Firstly, wood flour was added at different levels (0, 5, 10, and 20%) to polylactic acid (PLA) polymer to produce filaments. Then, mechanical test samples were printed from the produced filaments with a 3D printer. The produced filaments were made into pellets, and sheets were obtained by compression molding. According to the mechanical test results, it was observed that the tensile strength of the 3D-printed and compression-molded materials were close to each other, and the elasticity modulus of the compression-molded samples was higher than the 3D-printed samples. In the hardness comparison, the compression-molded specimens exhibited higher hardness values than the 3D-printed specimens. When the morphological properties of the materials were examined, it was seen that the cross-sections of the compression-molded materials were smooth and had less void than the 3D printed ones. The glass transition, crystallization, and melting temperatures of the materials did not change much with the processing methods. Only the 3D-printing process increased the crystallinity percentages.
Screening and characterization of a low-temperature-resistant cellulose-degrading strain, Trichoderma harzianum L-8, from a primitive forest
Authors: Wang Ruxian , Tao Dongxu , Li Jian , Chen Shengnan , Fan Jinxia , Bi Weishuai , Boboua Stopira Yannick Benz , Zheng Guoxiang
Published: May 2022

Low temperature is a major factor limiting the bio-sustainable and efficient conversion of cellulose-based resources in cold regions. In this study, a low-temperature resistant cellulose-degrading fungus with high cellulase production was screened from samples found in a primitive forest in Daqing by straw using the enrichment-restricted culture technique. The fungus was identified as genus Trichoderma harzianum, strain L-8 by morphological and molecular biological analysis. The enzyme production conditions were optimized via response surface methodology, and the optimal conditions for the enzyme production of Trichoderma harzianum L-8 were as follows: a CMC-Na addition of 10.63 g·L-1, an ammonium sulfate addition of 2.22 g·L-1, an initial pH of 5.29, and a lecithin addition of 5.18 g·L-1 when the CMCase reached 53.40 IU·mL-1. The leading enzyme families of Trichoderma harzianum L-8 were identified via proteomic analysis. Proteases including glycosyl hydrolase family 3-4 and cellobiohydrolase play important roles in cellulose degradation. The strain Trichoderma harzianum L-8 showed a strong cellulose degradation ability under low temperatures, providing strain resources for cellulose resource biotransformation technology in cold regions.
Effect of carpenter bee nests on timber building components Based on computed tomography (CT)
Authors: Gao Yisheng , Ge Zhedong , Fang Jiaqi , Yang Xiaoxia , Zhou Yucheng
Published: May 2022

The effects of carpenter bee nests were determined for components of timber buildings. An eaves purlin structure was taken as the experimental object, and medical computed tomography (CT) was used to reconstruct the sectional image of the eaves purlin. The digital image reconstruction technology was used to obtain three-dimensional (3D) images of the two eaves purlins. One eaves purlin was not damaged, and the other was seriously eroded by carpenter bees. The carpenter bee nests were displayed, and the two eaves purlins were simulated by the directional force and the uniform directional force. When the eaves purlin was under the downward pressure of the roof, the shear force at both ends of the eaves purlin and the pressure at the middle were relatively large. The results show that CT is an accurate and efficient technology for detecting the mechanical properties of timber building components. Nests are usually distributed in the eaves purlin eroded by carpenter bees, which destroy the stability of the eaves purlin structure and have a great impact on the stability of timber buildings. Therefore, this method to evaluate the damage degree of timber building components is very important for the protection of timber buildings.
Assessment of non-pressurized electro dewatering of waste activated sludge with graphite electrodes
Authors: Pakdil Nazlı Baldan , Balaban Serap
Published: May 2022

Changes of physical and chemical characteristics of sludge were investigated with respect to the pH, process time, and applied voltage by means of the electric field treatments. A model reactor with the desired speed was used to generate an electric field to separate water from the sludge without applying pressure. All electrodes mounted on the reactor were produced from graphite. Two different distances between anode and cathode (2.3 cm and 4.3 cm) were used to examine the effects on dewatering capacity of sludge. Differentiations of dependent variables inferred from the experimental processes were also surveyed by Box-Behnken experimental design. The water in the sludge was separated effectively when the samples were exposed to an electric field. The total solid increased from 1.07% to 6.60% at pH 6.5 when sludge was exposed to 25 V for 60 min. Furthermore, the optimum distance between electrodes was 2.3 cm for dewatering of sludge samples, where the capillary suction time of influent sludge was observed to decrease by approximately 85.5% at raw sludge pH. Similarly, the viscosity parameters decreased by approximately 99%. There was an increase in the soluble chemical oxygen demand, PO4-P, and NH4-N concentrations of water discharged from the model reactor.
The effect of body mass on designing the structural elements of wooden chairs
Authors: Hitka Miloš , Naď Milan , Gejdoš Miloš , Joščák Pavol , Jurek Andrej , Balážová Žaneta
Published: May 2022

This study aimed to evaluate the effect of increased body mass of users on the structural loading of wooden chair elements following the changes in anthropometric parameters in the adult population of the Slovak Republic. Moreover, the functional parts of a wooden chair most affected by the weight gain of an adult population were defined. The strength analysis of the tested chair was conducted using the program ANSYS. In the software environment, the 3D volume model taking into consideration orthotropic properties of wood was created. The structural elements of chairs for the current adult population are designed for the weight of 110 kg. The results suggest that the weight necessary for designing the structural elements of chairs must be 150 kg (130 kg + 15%). Comfort, physical health, well-being, performance, and security can be increased by designing such a device and equipment meeting the needs of the human body in a long-term viewpoint. It is suggested to create the standard taking into account men with a weight of up to 150 kg. Based on the results of the strength analyses, a chair load with a user’s weight of 150 kg will require a change in the dimensions of the side rails and the cross-section of the legs. The new knowledge gained is helpful for a better design of chair wooden elements taking into account the anisotropic (directional) structure of natural wood.
Performance of a high rate two-stage anaerobic membrane bioreactor (AnMBR) for the treatment of palm oil mill effluent
Authors: Chaipetch Wiparat , Khongnakorn Watsa , Yirong Chaowana , Boonkan Jomjai , Jaiyu Arisa , Heran Marc
Published: May 2022

A two-stage submerged anaerobic membrane bioreactor (2-sAnMBR) was operated to demonstrate the technology concept and to accelerate anaerobic biodegradation of Palm Oil Mill Effluent (POME). Then, the impact of different high organic loading rates (OLR) was investigated with a focus on water quality and biogas production. OLR higher than 50 kgCOD.m-3.d-1 induced an increase of volatile fatty acids (VFAs). As a consequence, the biogas production decreased from 19.8 to 11.0 L.d-1 and CH4 yield between 0.23 to 0.38 LCH4/gCODremoved. Nevertheless, the highest OLR (98 kgCOD.m-3.d-1) made it possible to reach a COD removal effectiveness of 70%, where the membrane contribution was around 23.9% to 34.7%. The ratio of propionic acid/acetic acid appeared to be a key indicator to prevent the AnMBR operation failure. Indeed, as soon as the value of 0.7 has been exceeded, several signs of AnMBR failure appeared. The methanogenic activity in AnMBR was inhibited by a hydrolysis ratio of 13% which transformed to VFA accumulation in system. The 250 mg.L-1 of Phenol concentration in POME was an inhibitory of the microbe in this system. Suspended solids concentration, proteins, polysaccharides, and volatile fatty acids were the substantial parameters that influenced the fouling rate.