bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute effects of different balance exercise types on selected measures of physical fitness in youth female volleyball players
Authors: Hammami Raouf , Chaabene Helmi , Kharrat Fatma , Werfelli Hanen , Duncan Michael , Rebai Haithem , Granacher Urs
Published: March 2021

Background

Earlier studies have shown that balance training (BT) has the potential to induce performance enhancements in selected components of physical fitness (i.e., balance, muscle strength, power, speed). While there is ample evidence on the long-term effects of BT on components of physical fitness in youth, less is known on the short-term or acute effects of single BT sessions on selected measures of physical fitness.

Objective

To examine the acute effects of different balance exercise types on balance, change-of-direction (CoD) speed, and jump performance in youth female volleyball players.

Methods

Eleven female players aged 14 years participated in this study. Three types of balance exercises (i.e., anterior, posterolateral, rotational type) were conducted in randomized order. For each exercise, 3 sets including 5 repetitions were performed. Before and after the performance of the balance exercises, participants were tested for their static balance (center of pressure surface area [CoP SA] and velocity [CoP V]) on foam and firm surfaces, CoD speed (T-Half test), and vertical jump height (countermovement jump [CMJ] height). A 3 (condition: anterior, mediolateral, rotational balance exercise type) × 2 (time: pre, post) analysis of variance was computed with repeated measures on time.

Results

Findings showed no significant condition × time interactions for all outcome measures (p > 0.05). However, there were small main effects of time for CoP SA on firm and foam surfaces (both d = 0.38; allp < 0.05) with no effect for CoP V on both surface conditions (p > 0.05). For CoD speed, findings showed a large main effect of time (d = 0.91;p < 0.001). However, for CMJ height, no main effect of time was observed (p > 0.05).

Conclusions

Overall, our results indicated small-to-large changes in balance and CoD speed performances but not in CMJ height in youth female volleyball players, regardless of the balance exercise type. Accordingly, it is recommended to regularly integrate balance exercises before the performance of sport-specific training to optimize performance development in youth female volleyball players.

Trial registration

This study does not report results related to health care interventions using human participants and therefore it was not prospectively registered.
Effective chemotherapy and targeted therapy supplemented with stereotactic radiotherapy of a patient with metastatic colon cancer following renal transplantation: a case report
Authors: Bellyei Szabolcs , Boronkai Árpád , Pozsgai Eva , Fodor Dávid , Mangel László
Published: March 2021

Background

Previous studies have shown that patients who underwent renal transplantation were at a greater risk of developing malignancies. Due to advances in effective surgical techniques and immunosuppressive therapies, organ recipients live longer. Yet, there is insufficient information about the recommended type of therapy for colorectal cancer patients following transplantation. We describe the oncological treatment of a patient with renal transplantation, who presented with metastatic colon cancer 5 years after transplantation.

Case presentation

A 66-year-old Caucasian male patient, with hypertension, type 2 diabetes mellitus, paroxysmal atrial fibrillation, and renal failure underwent successful kidney transplantation in 2013. In April 2018, the adenocarcinoma of the sigmoid colon was found, and surgical resection was performed. The histological diagnosis was low-grade adenocarcinoma. Fluorodeoxyglucose positron emission tomography/computerized tomography scan showed a 2.5-cm metastasis in the VIIth segment of the liver and a metastatic paraaortical lymph node on the left. The clinical diagnosis was, therefore, metastatic (stage IV) sigmoid colon cancer (AJCC TNM system). The ongoing medications of the patient included immunosuppressive drugs and medication for his cardiovascular comorbidities. In July 2018, palliative cetuximab plus folinic acid–fluorouracil–irinotecan chemotherapeutic treatment was initiated, then cetuximab was substituted for panitumumab because of adverse events. In August 2018, the follow-up positron emission tomography/computerized tomography scan revealed stable disease. Because of side effects, the patient was unwilling to continue with the panitumumab plus folinic acid–fluorouracil–irinotecan treatment regimen. Therefore, the patient received 10× 5 Gy stereotactic body irradiation for his liver metastasis and mono-panitumumab therapy. By January 2019, the positron emission tomography/computerized tomography scan showed regression of the liver metastasis but a progression in the paraaortic lymph node. Therefore, 5× 8 Gy stereotactic irradiation was given to the paraaortic lesion. Meanwhile, the patient received altogether 16 cycles of panitumumab until June 2019, when complete remission was attained. In July 2019, the patient suffered a hemorrhagic stroke, probably due to his cardiovascular comorbidities, and died subsequently.

Conclusions

Since information is scarce regarding oncological treatment of patients following organ transplantation, data about their oncological treatment is essential. To our knowledge, this is the first case report to describe the successful chemotherapy and targeted therapy supplemented with stereotactic radiotherapy of a posttransplant patient with metastatic colorectal cancer.
Research on Sturm–Liouville boundary value problems of fractional p-Laplacian equation
Authors: Xue Tingting , Kong Fanliang , Zhang Long
Published: March 2021

In this work we investigate the following fractionalp-Laplacian differential equation with Sturm–Liouville boundary value conditions:$$ \textstyle\begin{cases} {}_{t}D_{T}^{\alpha } ( { \frac{1}{{{{ ( {h ( t )} )}^{p - 2}}}}{\phi _{p}} ( {h ( t ){}_{0}^{C}D_{t}^{\alpha }u ( t )} )} ) + a ( t ){\phi _{p}} ( {u ( t )} ) = \lambda f (t,u(t) ),\quad \mbox{a.e. }t \in [ {0,T} ], \\ {\alpha _{1}} {\phi _{p}} ( {u ( 0 )} ) - { \alpha _{2}} {}_{t}D_{T}^{\alpha - 1} ( {{\phi _{p}} ( {{}_{0}^{C}D_{t}^{\alpha }u ( 0 )} )} ) = 0, \\ {\beta _{1}} { \phi _{p}} ( {u ( T )} ) + {\beta _{2}} {}_{t}D_{T}^{ \alpha - 1} ( {{\phi _{p}} ( {{}_{0}^{C}D_{t}^{\alpha }u ( T )} )} ) = 0, \end{cases} $${DTαt(1(h(t))p−2ϕp(h(t)0CDtαu(t)))+a(t)ϕp(u(t))=λf(t,u(t)),a.e. t∈[0,T],α1ϕp(u(0))−α2tDTα−1(ϕp(0CDtαu(0)))=0,β1ϕp(u(T))+β2tDTα−1(ϕp(0CDtαu(T)))=0,where${}_{0}^{C}D_{t}^{\alpha }$Dtα0C,${}_{t}D_{T}^{\alpha }$DTαtare the left Caputo and right Riemann–Liouville fractional derivatives of order$\alpha \in ( {\frac{1}{2},1} ]$α∈(12,1], respectively. By using variational methods and critical point theory, some new results on the multiplicity of solutions are obtained.
Protists as main indicators and determinants of plant performance
Authors: Guo Sai , Xiong Wu , Hang Xinnan , Gao Zhilei , Jiao Zixuan , Liu Hongjun , Mo Yani , Zhang Nan , Kowalchuk George A. , Li Rong , Shen Qirong , Geisen Stefan
Published: March 2021

Background

Microbiomes play vital roles in plant health and performance, and the development of plant beneficial microbiomes can be steered by organic fertilizer inputs. Especially well-studied are fertilizer-induced changes on bacteria and fungi and how changes in these groups alter plant performance. However, impacts on protist communities, including their trophic interactions within the microbiome and consequences on plant performance remain largely unknown. Here, we tracked the entire microbiome, including bacteria, fungi, and protists, over six growing seasons of cucumber under different fertilization regimes (conventional, organic, andTrichodermabio-organic fertilization) and linked microbial data to plant yield to identify plant growth-promoting microbes.

Results

Yields were higher in the (bio-)organic fertilization treatments. Soil abiotic conditions were altered by the fertilization regime, with the prominent effects coming from the (bio-)organic fertilization treatments. Those treatments also led to the pronounced shifts in protistan communities, especially microbivorous cercozoan protists. We found positive correlations of these protists with plant yield and the density of potentially plant-beneficial microorganisms. We further explored the mechanistic ramifications of these relationships via greenhouse experiments, showing that cercozoan protists can positively impact plant growth, potentially via interactions with plant-beneficial microorganisms includingTrichoderma,the biological agent delivered by the bio-fertilizer.

Conclusions

We show that protists may play central roles in stimulating plant performance through microbiome interactions. Future agricultural practices might aim to specifically enhance plant beneficial protists or apply those protists as novel, sustainable biofertilizers.
Control trial of porcine cysticercosis in Uganda using a combination of the TSOL18 vaccination and oxfendazole
Authors: Nsadha Zachary , Rutebarika Chris , Ayebazibwe Chrisostom , Aloys Bukenya , Mwanja M. , Poole E. Jane , Chesang Elizabeth , Colston Angela , Donadeu Meritxell , Lightowlers Marshall W.
Published: March 2021

Background

Neurocysticercosis caused by Taenia solium when the parasite lodges in the central nervous system, is an important cause of human seizures and mortality in sub-Saharan Africa. The parasite is prevalent in many regions of Uganda. Pigs are intermediate hosts for T. solium, and we evaluated a T. solium control program in pigs, involving vaccination of pigs with the TSOL18 vaccine and treatment with oxfendazole.

Methods

The study was conducted in two districts of Eastern Uganda involving the rural village communities of Bukedea (intervention area) and Kumi (control area) during 2016–2017. Seven hundred and thirty-four households were enrolled in the study. Pigs in the intervention area received intramuscular immunizations with TSOL18 (Cysvax™) and an oral medication with 30 mg/kg oxfendazole (Paranthic™) at approximately 3-monthly intervals for 18 months. Porcine cysticercosis was evaluated by post-mortem examination. At the beginning of the study, 111 pigs were examined. In an interim evaluation in the intervention area, 55 pigs were evaluated 12 months after starting the project. At the end of the study approximately 3 months after the final intervention, 55 pigs from the intervention area and 56 pigs from the control area were evaluated.

Results

The prevalence of porcine cysticercosis for the two sites was 16.2% at the beginning of the study (17.2% in the intervention area and 15.1% in the control area) with no statistically significant difference (P = 0.759) between the two study sites. Among the 110 animals assessed from the intervention site (55 at the interim evaluation and 55 at the final evaluation), no pig with viable T. solium cysts was found. There was a statistically significant difference between the prevalence at baseline (17.2%) and at the end of the study (0%) in the intervention area (P = 0.001) and a statistically significant difference between the intervention (0%) and control areas (5.4%) (P = 0.041) at the end of the study.

Conclusions

Three-monthly concurrent vaccination of pigs with the TSOL18 vaccine and medication with oxfendazole eliminated T. solium transmission by the animals involved in the study. Application of vaccination with medication in pigs has the potential to reduce transmission of T. solium in Uganda and other endemic countries.
“Case series: ischemic stroke associated with dehydration and arteriosclerosis in individuals with severe anorexia nervosa”
Authors: Mimura Yu , Shimizu Yusuke , Oi Hiroki , Kurose Shin , Kudo Shun , Takata Taketo , Mimura Masaru , Funayama Michitaka
Published: March 2021

Background

Numerous reports have indicated that patients with anorexia nervosa (AN) are at a relatively high risk of developing vascular diseases, including cardiovascular events and venous thromboembolism. However, there have been no previous reports of the development of ischemic stroke during refeeding therapy in patients with severe AN. This report is aimed at reporting the characteristics of an ischemic stroke in patients with AN.

Case presentations

Our study included 29 admissions by independent 19 female patients cases (19 patients), who received thorough medical, neurological, and psychiatric examinations. Two patients were diagnosed as having developed ischemic stroke; the first patient showed multiple infarctions in the brain, while the second showed symptomatic focal infarction. Our findings suggest that dehydration and arteriosclerosis, in association with severe malnutrition, could predispose to the development of ischemic stroke in patients with severe AN.

Conclusions

Development of ischemic stroke in patients with AN might be overlooked. Watching out for neurological signs would help in early diagnosis of ischemic stroke in patients with AN during refeeding. Specific etiology could induce ischemic stroke in patients with AN even if they have no common risk factors of ischemia.
Effect of oral isotretinoin on muscle strength in patients with acne vulgaris: a prospective controlled study
Authors: Mülkoğlu Cevriye , Karaosmanoğlu Nermin
Published: March 2021

Background

Musculoskeletal side effects related to isotretinoin are frequently reported. This study aimed to investigate the effect of oral isotretinoin treatment on muscle strength. Our second aim was to evaluate whether there was a correlation between the serum creatine phosphokinase (CPK) level, a specific marker of muscle breakdown, and muscle strength.

Methods

This study included 30 patients who presented to our hospital and were started on oral isotretinoin treatment for acne vulgaris and 30 patients in the control group who were given local treatment. Age, sex, height and weight of the patients were recorded, and the body mass index (BMI) was calculated. The hamstring and quadriceps muscle strengths of the non-dominant side were evaluated in all patients using an isokinetic dynamometer, and the peak torque (PT) values ​​were recorded. In the isotretinoin group, isokinetic measurements were performed again in those that completed six-month drug treatment and compared with the initial PT values.

Results

The two groups were similar in terms of age, sex, and BMI (p > 0.05). There was no significant difference between the isotretinoin and control groups in terms of muscle strength at the beginning of the treatment (p > 0.05). No significant change was observed in hamstring and quadriceps PT values in the isotretinoin group after 6 months of treatment compared to baseline (p > 0.05). No statistically significant correlation was found between the serum CPK level and hamstring and quadriceps muscle strength (p > 0.05).

Conclusion

Oral isotretinoin doesn’t alter muscle strength. There is no relationship between the serum CPK levels and muscle strength.
Organ specific responses to first-line lenvatinib plus anti-PD-1 antibodies in patients with unresectable hepatocellular carcinoma: a retrospective analysis
Authors: Huang Cheng , Zhu Xiao-Dong , Shen Ying-Hao , Wu Dong , Ji Yuan , Ge Ning-Ling , Chen Ling-Li , Tan Chang-Jun , Zhou Jian , Fan Jia , Sun Hui-Chuan
Published: March 2021

Background

We evaluated organ-specific response rates (OSRRs) to first-line lenvatinib plus anti-PD-1 antibodies in patients with advanced hepatocellular carcinoma (HCC).

Methods

This retrospective analysis included Chinese patients with unresectable/advanced HCC who received first-line lenvatinib (8 mg/day) plus ≥3 infusions of anti-PD-1 antibodies between October 2018 and May 2020. Tumor and macrovascular tumor thrombi (MVTT) treatment responses were evaluated every 2 months using RECIST v1.1. The overall response rate (ORR)/OSRR was defined as the percentage of patients with a best overall response of complete or partial response (CR or PR).

Results

In total, 60 patients were included in the analysis; 96.7% had measurable intrahepatic lesions, 55% had MVTT and 26.7% had extrahepatic disease. In all 60 patients, the ORR was 33.3%, median progression-free survival was 7.0 months (95% CI, 1.7–12.3) and median overall survival was not reached. The OSRR for MVTT (54.5%) was higher versus intrahepatic tumors (32.8%), extrahepatic lung metastases (37.5%) and lymph node metastases (33.3%). Among 33 patients with intrahepatic tumors and MVTT, 18 had differential responses in each site, including 13 with a better response in MVTT versus intrahepatic lesions. Among 18 patients whose MVTT achieved a radiographic CR or PR, six underwent surgical resection: 4/6 achieved a pathological CR in MVTT and 2/6 in the intrahepatic tumor.

Conclusions

First-line lenvatinib plus anti-PD-1 antibodies resulted in better tumor responses in MVTT versus intrahepatic lesions. Complete MVTT necrosis may allow downstaging and subsequent eligibility for surgical resection in a proportion of patients with advanced HCC.
Statistics of the early synthetic dye industry
Authors: Hagan Eric , Poulin Jennifer
Published: March 2021

From the invention of Perkin’s Mauve in 1856, to publication of the first edition of the Colour Index in 1924, more than 1200 synthetic organic colourants were introduced. Some achieved commercial success, while others were rarely used for reasons such as high cost, low fastness, and toxicity. This turbulent period of innovation was largely driven by demand of the textile industry; however, synthetic colourants were subsequently adopted in many other applications. An understanding of the most common materials and their properties is therefore important to the study of heritage collections and their preservation. The risk of light damage during exhibition of objects is often a concern due to the fugitive nature of many synthetic colourants.

To provide a foundation for focused research on synthetic dye identification and lightfastness, work was carried out to identify the most prominent of these colourants used in North America up to the year 1924 when the first edition of the Colour Index was published. Information was compiled and analysed from several sources including multiple editions of the Colour Index, and government documents related to the manufacture and trade of synthetic dyes that provide data from 1914 onwards. Cross-referencing between the information sources provided a summary of parameters for each colourant including the date of introduction, number of manufacturers, lightfastness, and quantity produced or imported in the United States.

A document published in 1916 by the US Department of Commerce listed 259 colours with Schultz number imported during the 1913–1914 fiscal year, in quantities above 10,000 lb (4536 kg). Adding domestic products to the list, and removing duplicates, gave 289 individual colours with Schultz number imported and/or produced in the US. In addition, there were some imports of unknown composition: 96 azo, 23 sulphur, and 68 unclassified. Further review of census data from 1917 through the 1920’s suggested that less than one quarter of the dyes listed in the Colour Index were imported or manufactured in significant amounts. The results of this analysis are presented as summary statistics, which are complemented by an open dataset publication to facilitate future research.
Examining educational inequalities: insights in the context of improved mathematics performance on national and international assessments at primary level in Ireland
Authors: Karakolidis Anastasios , Duggan Alice , Shiel Gerry , Kiniry Joanne
Published: March 2021

Background

Evaluations of effectiveness of educational reforms are often based on the level of improvement in student performance from one cycle of a particular assessment to the next. However, improvements in overall performance do not necessarily translate to improved equality. Indeed, improvements that favour certain subgroups of students can exacerbate educational performance gaps and thus, inequality. This research examines changes in equality of mathematics achievement and subgroup performance differences in Irish primary school students over time. Ireland constitutes an interesting case study due to the introduction of a new National Literacy and Numeracy Strategy in 2011, the initial implementation of which has been linked to significant improvements in student mathematics performance. This paper aims to investigate whether these improvements have been accompanied by improvements in equality.

Methods

Using data from the Irish National Assessments of Mathematics and English Reading (NAMER) and the Trends in International Mathematics and Science Study (TIMSS) from the period before and after the introduction of the Strategy, the study examines (i) deviations in student scores, (ii) variability in achievement at student and school levels and (iii) performance gaps based on demographic and socioeconomic factors over time. Bivariate analyses and multilevel regression models were used to identify student- and school-level variables related to mathematics performance.

Results

The results showed a decrease in variability in students’ mathematics performance after the introduction of the Strategy; this decrease was statistically significant only for TIMSS. Additionally, there was a considerable decrease in variance in mathematics performance attributed to between-school differences over time. These findings constitute evidence of increased equality as performance differences between students and schools tended to shrink. Regarding performance gaps and variance in mathematics performance explained by background characteristics, this study provided mixed results. In NAMER, subsequent to the introduction of the Strategy, the performance gaps and variance in mathematics achievement explained by selected demographic and socioeconomic characteristics decreased considerably. However, this was not the case for TIMSS.

Conclusions

The evidence provided by this study suggests that Ireland has made reasonable progress in addressing inequality. However, there is room for improvement, as a significant proportion of the variance in student mathematics performance is still explained by demographic and socioeconomic characteristics.
Insurance disparity in cardiovascular mortality among non-elderly cancer survivors
Authors: Shi Tiantian , Jiang Changchuan , Zhu Cenjing , Wu Fangcheng , Fotjhadi Irma , Zarich Stuart
Published: March 2021

Background

Insurance status plays a vital role in cancer diagnosis, treatments and survival. Cancer patients have higher cardiovascular disease (CVD) mortality than the general population.

Methods

The Surveillance, Epidemiology and End Results (SEER) program 2007–2016 was used to estimate the CVD mortality among cancer patients aged 18 to 64 years at the time of diagnosis of an initial malignancy with the eight most prevalent cancers. Standardized mortality ratios (SMRs) were calculated for each insurance (Non-Medicaid vs Medicaid vs Uninsured) using coded cause of death from CVD with adjustment of age, race, and gender. The Fine-Grey Model was used to estimate adjusted Hazard Ratios (HR) of each insurance in CVD mortality.

Results

A total of 768,055 patients were included in the final analysis. CVD death in patients with Medicaid insurance remained higher than in those with Non-Medicaid insurance (HR = 1.71; 95%CI, 1.61–1.81; p < 0.001). Older age, male gender, and black race were all associated with increased CVD mortality in the multivariable model. Compared to the general population, patients with Medicaid had the highest SMRs of CVD mortality, regardless of year of cancer diagnosis, follow-up time, cancer site, and race. Non-Medicaid insured patients had similar CVD mortality to the general population after 2 years out from their cancer diagnosis.

Conclusion

Cancer patients with Non-Medicaid insurance have significantly lower CVD mortality than those with no insurance or Medicaid. The insurance disparity remained significant regardless of type of CVD, cancer site, year of diagnosis and follow-up time.
Efficacy of Clonostachys rosea, as a promising entomopathogenic fungus, against coleopteran stored product insect pests under laboratory conditions
Authors: Mohammed Akram A. , Younus Amal S. , Ali Abdulla N.
Published: March 2021

Background

Efficacy of new isolates of the entomopathogenic fungus (EPF), Clonostachys rosea, against adult stage of the most serious coleopteran stored product insect pests in Iraq, Trogoderma granarium Everts (Coleoptera: Dermestidae), Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) and Callosobruchus maculatus Fabricius (Coleoptera: Chrysomelidae), was evaluated under laboratory conditions. Two isolates of C. rosea, associated with the green peach aphid (Myzus persicae Sulz.), were isolated and investigated. Efficacy of C. rosea isolates was evaluated by two concentrations (1 × 108 and 1 × 106 conidia ml−1).

Results

Corrected mortality rates caused by both C. rosea isolates, 6 days post-treatment, with 1 × 108 conidia ml−1, ranged from 70.7 to 75.7%. Fungal infection caused 37–53% reduction in total fecundity of the adult females of the three tested insect species, 6 days post-treatment.

Conclusion

Obtained results demonstrated that C. rosea isolates had potentials as a biological control agent against coleopteran stored product insect pests. However, further studies under commercial storage conditions are required.
Ethnomedicinal herbs in African traditional medicine with potential activity for the prevention, treatment, and management of coronavirus disease 2019
Authors: Adeleye Olutayo Ademola , Femi-Oyewo Mbang Nyong , Bamiro Oluyemisi Adebowale , Bakre Lateef Gbenga , Alabi Akinyinka , Ashidi Joseph Senu , Balogun-Agbaje Olalekan Adeyinka , Hassan Oluwakemi Mary , Fakoya Gbemisola
Published: March 2021

Background

Ethnomedicine, a study of traditional medicine, is significant in drug discovery and development. African traditional medicine has been in existence for several thousands of years, and several drugs have been discovered and developed from it.

Main text

The deadly coronavirus disease 2019 (COVID-19) caused by a novel coronavirus known as SARS-CoV-2 has widely spread globally with high mortality and morbidity. Its prevention, treatment and management still pose a serious challenge. A drug for the cure of this disease is yet to be developed. The clinical management at present is based on symptomatic treatment as presented by individuals infected and this is by combination of more than two drugs such as antioxidants, anti-inflammatory, anti-pyretic, and anti-microbials. Literature search was performed through electronic searches of PubMed, Google Scholar, and several research reports including WHO technical documents and monographs.

Conclusion

Drug discovery from herbs is essential and should be exploited for the discovery of drugs for the management of COVID-19. This review is aimed at identifying ethnomedicinal herbs available in Africa that could be used for the discovery and development of a drug for the prevention, treatment, and management of the novel coronavirus disease 2019.
INCREASING THE RESISTANCE OF THE ELECTRONIC COMPONENT BASE TO THE DOSE EFFECTS OF RADIATION EXPOSURE
Authors: Kozyukov Aleksandr , Zolnikov Konstantin , Mescheryakov Sergey , Groshev Artem , Sysoev Dmitriy
Published: March 2021

The article considers the issues of increasing the resistance of the electronic component base (ECB) to dose effects due to the improvement of the technological process. Graphs of the functions of the transfer characteristics of MOSFETs and CMOS inverters before and after radiation exposure are presented. The effect of the charge in the oxide and on the surface formed under the action of radiation is shown.
MODELING OF PROCESSES AFFECTING THE QUALITY OF CONCRETE ROAD SURFACES
Authors: Merkulov Aleksandr , Nikolenko S. , Sazonova Svetlana
Published: March 2021

This paper considers the main processes that affect the quality of concrete pavements. The processes of quality control of concrete constituents, the process of its production, as well as control of road surfaces that have fully gained strength and are ready for use are considered. Examples of defect formation on concrete pavements are given. The factors influencing their appearance and the measures that exclude their formation are considered.
ANALYTICAL CALCULATION OF LEAKAGE INDUCTANCES BASED ON THE APPLICATION OF THE VECTOR POTENTIAL OF THE MAGNETIC FIELD
Authors: Viharev Dmitriy , Snit'ko Irina , Tihonov A.
Published: March 2021

Methods for calculating the intrinsic and mutual leakage inductances based on the use of the vector potential of the magnetic field are considered, expressions are derived for the quantitative determination of the intrinsic and mutual inductances of the leakage fields, taking into account the geometric features of the coils, conductors and the relative position of the objects under study. The results obtained can be used to determine the parameters of the refined equivalent circuits of power transformers.
SOFTWARE FOR CONTROL SYSTEMS FOR «SMART» RESIDENTIAL BUILDING
Authors: Polyakov Sergey , Akimov V. , Polukazakov A. , Zolnikov Vladimir , Enin P.
Published: March 2021

The article deals with the issues of modeling and management of life support systems of a residential building. The resulting model of the liquid level in the tank allows you to establish the relationship between the level and the flow rate of the liquid. The results of the selection and justification of the fluid level control structure are presented. An algorithm that implements the operation of a virtual object is given. The structure of the automatic control system (ACS) of the liquid level is technically implemented in an open type. The results confirming the achievability of the proposed structural changes are obtained. The results of experimental studies are presented. The choice and justification of the method of controlling the heating system and the liquid level in the tank are considered. Programs for managing subsystems of a residential building in Assembly language, C++, and ladder diagrams are presented. A model for controlling the liquid level in a Multisim environment is proposed.
VISUALIZATION OF METALWORKING PROCESSES IN THE DEVELOPMENT OF SIMULATION PROGRAMS FOR CNC EQUIPMENT
Authors: Yurov Aleksey , Antsiferova V. , Pachevskiy Denis
Published: March 2021

The article discusses the problems associated with the visualization of metalworking processes, describes the approaches and presents the implementation in the form of software modules, which show the imitation of the work of turning and milling. The developed modules simulate metalworking according to the instructions of the control programs in the G-code. The implementation of the modules is prepared for simple control programs; however, the developed software applications provide for the expansion of the functionality of the simulation processes in metalworking. The results of the work of the modules can be transferred to third-party CAD systems using export data formats.
Developing digital module for human literacy and technology literacy
Authors: Hartanto Dody , Prasetyo Puguh Wahyu , Maryani Ika , Maharani Ega Asnatasia , Puspitasari Intan , Putri Diah Asta , Aji Oktira Roka , Purwanto Wachid Eko
Published: March 2021

In the era of industrial revolution 4.0, many human activities depend on the gadget and the internet connection. We can observe the daily activities of human life right now. When they wake up in the morning, they usually start by using their handphones or gadget. This condition motivates educators to build a digital module in order to use the positive point of view of the Industry Revolution 4.0 era. In this chance, the researchers develop two topics that are very important for human life in Industry Revolution 4.0, whicht are, human literacy and technology literacy. Both of the topics were derived into two-courses. The course of development of students (Perkembangan Peserta Didik) will be representing the human literacy topics and the course of introduction to Biotechnology (pengantar bioteknologi) will be representing the technology literacy topic. The research is research and development. Furthermore, the products of this research are flipbooks that were uploaded on the Learning Management System managed by Universitas Ahmad Dahlan.
Assessment of the Validity and Reliability of Mental Health Instruments of High School Student in Indonesia
Authors: Hidayati Heny Narendrany , Hayat Bahrul , Rahayu Wardani
Published: March 2021

This study aims to develop a standard instrument for measuring mental health among urban adolescents in Indonesia. The objective is to produce valid and reliable school adolescent mental health instruments to be used by agencies or schools to identify students' mental health. The survey was conducted in Jakarta and South Tangerang with a total of 1007 respondents divided into two experiments where the first trial was conducted on 597 students and the second trial was conducted on 410 students. Measurements were made using a Likert scale questionnaire. Instrument testing begins with a theoretical validity test by 4 experts and 20 panelists who test the instrument material in terms of construction, content and language. Experts analyze and correct the instrument qualitatively. The instrument was then reviewed and analyzed quantitatively by panelists using the Aiken index. At this stage, 44 items, 9 indicators and 3 variable dimensions were obtained. The next test is done by testing the validity empirically, by analyzing the measurement model using Confirmatory Factor Analysis (CFA) with the LISREL 8.80 Full Version program. By using the criteria for the SLF value ≥0.30 and t-value ≥1.96, and calculating the reliability with the construct reliability (CR) at the level> 0.70, the results of the second trial showed that 35 items were valid. The observations of the model fitness through Goodness-of-Fit test showed that there is a fitness between the theoretical model and the empirical model for the mental health instruments in this study.
Exploring Students’ Learning Strategies and Self-Regulated Learning in Solving Mathematical Higher-Order Thinking Problems
Authors: Ansari Bansu Irianto , Saleh Muhamad , Nurhaidah Nurhaidah , Taufiq Taufiq
Published: March 2021

Considering the low achievement of Indonesian students in international studies (PISA), which measures Higher-Order Thinking Skill (HOTS) in solving the problem, improving the quality of mathematics learning in Indonesia is very important. The purpose of this research was conducted to explore the variations in students’ learning strategies and students’ Self–Regulated Learning (SRL) in solving mathematical HOT problems. The study employed a mixed-method, namely quantitative and qualitative methods were applied through five tests and seven interviews for over eight weeks. Two types of instruments were employed in this study, and they include tests and interviews. At the initial stage, we randomly selected 30 students from all those in grade 10 (Senior High School ), after which 12 were chosen purposively after the pre-test for an interview, having satisfied all complete group, middle group, and lower group. All of them were treated using metacognitive questions. Data analysis techniques used were percentage, data reduction, presentation, and conclusion. The quantitative results showed the students could generally use orientation, organization, and elaboration learning strategies as observed with 68.3%, 60%, and 56.7% for complete, middle, and lower groups. Moreover, the students were also observed to have conducted three cognitive processes in selecting the rules for solving the mathematical HOT problem, namely using models and drawing, written texts, and combining both. Furthermore, their final solution failures were affected by their misconceptions and errors in creating the mathematical model. The interview results on designing the learning procedures, monitoring the progress, and evaluating the outcomes, show that the students’ SRL level is good for complete (89.3%), middle (75%), and lower groups (60.7%).
Spectral theory for self-adjoint quadratic eigenvalue problems - a review
Authors: Lancaster Peter , Zaballa Ion
Published: March 2021

Many physical problems require the spectral analysis of quadratic matrix polynomials $M\lambda^2+D\lambda +K$, $\lambda \in \mathbb{C}$, with $n \times n$ Hermitian matrix coefficients, $M,\;D,\;K$. In this largely expository paper, we present and discuss canonical forms for these polynomials under the action of both congruence and similarity transformations of a linearization and also $\lambda$-dependent unitary similarity transformations of the polynomial itself. Canonical structures for these processes are clarified, with no restrictions on eigenvalue multiplicities. Thus, we bring together two lines of attack: (a) analytic via direct reduction of the $n \times n$ system itself by $\lambda$-dependent unitary similarity and (b) algebraic via reduction of $2n \times 2n$ symmetric linearizations of the system by either congruence (Section 4) or similarity (Sections 5 and 6) transformations which are independent of the parameter $\lambda$. Some new results are brought to light in the process. Complete descriptions of associated canonical structures (over $\mathbb{R}$ and over $\mathbb{C}$) are provided -- including the two cases of real symmetric coefficients and complex Hermitian coefficients. These canonical structures include the so-called sign characteristic. This notion appears in the literature with different meanings depending on the choice of canonical form. These sign characteristics are studied here and connections between them are clarified. In particular, we consider which of the linearizations reproduce the (intrinsic) signs associated with the analytic (Rellich) theory (Sections 7 and 9).
Design and characterization of microstrip patch antennas for high-Tc superconducting terahertz emitters
Authors: Tsujimoto Manabu , Kaneko Youta , Kuwano Genki , Nagayama Kanae , Imai Takayuki , Ono Yukino , Kusunose Shinji , Kashiwagi Takanari , Minami Hidetoshi , Kadowaki Kazuo , Simsek Yilmaz , Welp Ulrich , Kwok Wai-Kwong
Published: March 2021

We designed and characterized a microstrip pattern of planar patch antennas compatible with a cuprate high-T
c
superconducting terahertz emitter. Antenna parameters were optimized using an electromagnetic simulator. We observed repeatable sub-terahertz emissions from each mesa fabricated on identical Bi2Sr2CaCu2O8+δ base crystals in a continuous frequency range of 0.35–0.85 THz. Although there was no significant output power enhancement, a plateau behavior at a fixed frequency was observed below 40 K, indicating moderate impedance matching attributable to the ambient microstrip pattern. A remarkably anisotropic polarization at an axial ratio of up to 16.9 indicates a mode-locking effect. Our results enable constructing compactly assembled, monolithic, and broadly tunable superconducting terahertz sources.
Quantitative analysis and optimization design of the segmented planar integrated optical imaging system based on an inhomogeneous multistage sampling lens array
Authors: Gao Weiping , Yuan Ying , Wang Xiaorui , Ma Lin , Zhao Zhenshun , Yuan Hang
Published: March 2021

The non-uniformity of the lens array in the segmented planar integrated optical imaging system has not been studied. We design an inhomogeneous multistage sampling lens array based on a hierarchical multistage sampling lens array of the segmented planar integrated optical imaging system by changing the radius of the lenslet for frequency-selective sampling to optimize the design of the UV spatial frequency distribution. The signal transfer model of the proposed imaging system was established considering the radius of the lenslet and key waveguide parameters. Simulation results show that the proposed system produces better imaging quality owing to the selective sampling of frequency. Compared with the homogeneous multistage sampling lens array (radius of 1.8 mm), the optimal radius parameters of the inhomogeneous multistage sampling lens array are given for the same longest lens array length. Detailed calculations of the parameters of the waveguide connected to the lens array were performed. Our results provide a theoretical basis for the optimal design and process of a new segmented planar integrated optical imaging system.
Analysis of the influence of antireflective coatings on the diffraction efficiency of diffractive optical elements
Authors: Fluder Grzegorz , Kowalik Andrzej , Rojek Anna , Sobczyk Artur , Choromański Zdzisław , Krężel Jerzy , Józwik Michał
Published: March 2021

Diffractive optical elements (DOEs) may be used as a single optical component with dedicated functionality (e.g. focusing), or as one of the elements in complex hybrid optical systems to reduce the number of the elements and improve imaging quality. It is desirable to cover DOE’s surface with antireflective coating. In this paper, we show the results of simulations using the Fourier modal method and measure the efficiency of a diffractive lens with antireflective (AR) coating. Results were compared with a previously proposed model of AR covered DOE by Mao et al. [Opt. Express 25, 11673 (2017)10.1364/OE.25.011673]. Contrary to the previously published model, we have not observed a shift of the efficiency curve. Our findings prove that AR coatings improve the efficiency of DOEs and it is not necessary to take them into account when calculating optimal profile height.
DNA Inhibition of Hydrogen Ion-Induced Corrosion of
Mild Steel Used for Pipelines in Oil and Gas Industries
Authors: Agboola Oluranti , Adedoyin Toluwani , Isaac Fayomi Ojo Sunday , Ayodeji Ayoola , Sanni Samuel E. , Ayeni Augustine Omoniyin , Popoola Patricia , Sadiku Rotimi , Alaba Peter Adeniyi , Akande Godwin I. , Okoro Emmanuel Emeka
Published: March 2021

Corrosion of mild steel via chemical reaction in a corrosive environment is a problematic occurrence
that is very common in oil and gas industries. Corrosion constitutes a huge part of the total costs in the
production of oil and gas. Corrosion inhibitors have found interest in the scientific domain because
they are mainly understood by their chemical complexes and formulations. Their utilization in small
amount on metal surface used in oil and gas industries can help shield the metal from corrosion devoid
of any significant alteration in the concentration of the corrosive media in the environment. An effort
was made to study the possibility of using calf thymus gland DNA (CTGDNA) inhibitor in chlorine
induced mild steel for possible usage in piping in oil and gas industry. The SEM micrograph shows
that the adsorption of the CTGDNA biomacromolecules coat on the mild steel surfaces functions as a
protection against HCl corrosive solution. Electrochemical study and weight loss analysis showed
that the inhibitor efficiency (70.48 and 72%, respectively) of the tested DNA (CTGDNA) in HCl acidic
corrosion environment for the mild steel was high at 1.5 M of HCl. The inhibitor efficiency decreased
with increasing HCl concentrations. The open circuit potential (OPC) revealed that the mild steels got
corroded until the end of the immersion. The intensities of XRD peak substantiate the existence of
corrosion products of FeCl2.
Graphene Oxide-Paraffin-Nanobentonite as Working
Electrode for Cyclic Voltammetry Analysis for Nicotinic Acid
Authors: SETIARSO PIRIM , SARI NERRY PUSPITA
Published: March 2021

The composition of graphene oxide (GO):paraffin:nanobentonite electrode was optimized to acquire the optimal working electrode to
analyze nicotinic acid under the optimum conditions through cyclic voltammetry. Graphene oxide was synthesized from graphite by
employing the improved Hummer method. Bentonite was synthesized using the sonothermal method. The ratio of GO:paraffin:nanobentonite
electrodes of 3:3:4 provided the optimal voltammogram. The results indicated that the composition of the comparative working electrodes
of GO-modified nanobentonite was best 3:3:4 with a good peak recovery averaged value of 96.16%.
Catalytic Reduction of 4-Nitrophenol to 4-Aminophenol using Chitosan Ag-TiO2 Nanocomposite
and its Applications in the Removal of Malachite Green by Photodegradation Technique
Authors: ANUSUYA N. , PRAGATHISWARAN C. , MARY J. VIOLET
Published: March 2021

A simple colloidal processing method was used to synthesize chitosan Ag-TiO2 nanocomposite and its use aimed at the catalytic reduction
of 4-nitrophenol to 4-aminophenol in the presence of NaBH4 as reductant. The nanocomposite catalyst was characterized using different
technquies and revealed its better catalytic ability than pure TiO2. Since the nanocomposites are readily improved from the solution phase
without centrifugation or filtration. The catalytic activity trials were examined by changing the catalyst dose, concentration of NaBH4,
amount of nitrobenzene and temperature. The reduction reactions were affected by the temperature of reaction medium and the concentration
of NaBH4. The photodegradation conditions were optimized by changing different parameters such as irradiation time, dosage, pH and
initial dye concentration.
Coral Limestone Modified by Magnetite and Maghemite Nanocomposites for Sequestration of Lead(II) and Chromium(VI) Ions from Aqueous Solution
Authors: NKUTHA C.S. , SHOOTO N.D. , NAIDOO E.B.
Published: March 2021

In present work, a one pot synthesis of magnetic nanocomposites was synthesized by using co-precipitation method in air atmosphere. The synthesis of magnetite and maghemite supported on biogenic coral limestone was done by varying the ratio of Fe(II)/Fe(III) in solution to obtain the two phases of iron oxide and capping with sucrose in air atmosphere. The nanocomposites were characterized by FTIR, where the results showed a distinct peak for Fe-O, while UV/vis showed an absorption in the visible region which is typical of iron oxide. Photoluminescence results showed that the nanocomposites were both red shifted for magnetite-PCLS (PCLS = pristine coral limestone) and magnetite-CCLS (CCLS = calcined coral limestone); while a blue shift and red shift was observed for the maghemite- PCLS and maghemite-CCLS. From the SEM a deviation of sphericity of the nanocomposites, with maghemite having an uneven distribution was observed. Equilibrium was reached within 60 min, of which maghemite showed higher metal uptake. The kinetic data fit PSOM better as compared to PFOM, this means that adsorption was due to the charge density on the surface of the nanocomposites. The good fit for intraparticle diffusion (IPD) also suggested that adsorption was also observed due to mass transfer, it was observed that the rate limiting step was due to surface adsorption. This was in good correlation with the better fit of PSOM. The mechanism of adsorption was found to be better explained by physisorption and the surface was heterogeneous whereby multilayer adsorption was possible. The data was also subjected to Dubinin-Radushkevich isotherm, which suggests that the uptake of the pollutants was due to physisorption. The adsorption process was spontaneous and favourable which is supported by the negative values of Gibb’s free energy for the system.