Material Research Articles

Microelements in Soils and Cenopopulation of Medicinal Plants

The article provides an analysis of the cenopopulation and element composition of the medicinal Capparis spinosa L. distributed in calcisols formed on eroded alluvial- proluvial rock-gravel rocks in the south of the Fergana Valley. The predominance of immature plants in the cenopopulation was detected in the Arsif hills, and quantitative indicators of micronutrients in the vegetative and generative organs of Capparis spinosa L. were determined. The study of biomorphological characteristics of the plant during the growing season (April-October) was carried out in the identified 10 observational experimental field populations. Soil, plant element analysis was performed by neutron-activation method. In this case, the samples were irradiated in a nuclear reactor with a neutron flux of 5 × 1013 neutrons/cm2sec, and their quantities were determined in accordance with the half-life of chemical elements. It has also been compared with research materials conducted by world scientists on the importance and pharmacological properties of botanicals in medicine and the food industry, as well as their botanical characteristics.

The Effectiveness of Chemistry Module Integrated with Islamic Values in Atomic Structure Materials on Online Learning of Integrated Islamic Senior High School

The research aims at a) developing a chemistry module integrated with Islamic values on atomic structure material, b) analyzing the feasibility and the effectiveness of the module in online learning. The type of this module is a digital module (PDF) published as the learning media in the pandemic era. The subjects of the research are grade X students in SMA IT Nur Hidayah and SMA IT Ibnu Abbas located in Soloraya. The samples consist of the control class and the experiment class selected by purposive sampling. The instrument of reliability was tested using Cronbach Alpha formula and the content of the module was validated using Aiken formula. The data analysis used was descriptive qualitative. The findings of the research show that the development of the chemistry module integrated with Islamic values was analyzed using Borg and Gall (1983) developing stages that consist of 9 stages. The chemistry module integrated with Islamic values is feasible and it is categorized as “very good” and effective to be used to develop the students' cognitive. Thus, the chemistry module integrated with Islamic values could be implemented to enhance the SMA Islam Terpadu students’ cognitive competencies in online learning.

Provisórios em prótese fixa: revisão integrativa da literatura e técnicas para confecção

INTRODUÇÃO: A prótese fixa provisória é uma parte importante do tratamento reabilitador, sendo uma fase intermediária necessária para a confecção das próteses definitivas. OBJETIVO: Apresentar materiais e suas propriedades; como também as técnicas para confecção de provisórios em Prótese Fixa, através de uma revisão de literatura integrativa. MATERIAL E MÉTODO: Busca dos artigos ocorreu na BVS e PubMed, publicados em português e inglês, entre 2000 a 2020. A estratégia de busca utilizada foi utilizando as palavras chave: (Denture, Partial, Temporary) AND (Polymers) AND (Denture, Partial, Fixed) AND ("Dental Prosthesis" OR "Flexural Strength" OR "Dental Polishing"). Foram incluídos estudos completos disponíveis; abordando o tema provisórios em Prótese Parcial Fixa sobre dente. Os critérios de exclusão foram estudos de provisórios em prótese sobre implante, revisões de literatura e relatos de caso. Os dados completos dos textos selecionados foram extraídos pelos revisores. Técnicas foram apresentadas quanto as etapas de confecção. RESULTADOS: Os estudos abordaram a aplicação de diferentes materiais e técnicas, além das pesquisas laboratoriais serem prevalentes. Observou-se uma heterogeneidade entre objetos de estudos e variáveis, destacando-se o uso de distintos polímeros, técnicas e adição do reforço. CONCLUSÃO: Há diversos materiais para a confecção de provisórios. As técnicas relatadas foram o uso do molde em silicone, matriz em acetato e CAD/CAM, e as mais comuns de serem executadas na clínica diária foram adaptação da faceta de estoque (sobre o preparo e dente tratado endodonticamente), resina adaptada ou bolinha e molde ou matriz em silicone.

From spoons to semiconductors — we are what we make

Through a tour of ten materials, a scientist explores knowing through doing. Through a tour of ten materials, a scientist explores knowing through doing.

DEALING WITH INDISCIPLINE AMONG JUNIOR HIGH SCHOOLS IN AGONA SWEDRU, AGONA WEST MUNICIPALITY, GHANA

The purpose of the study was to investigate measures that are in place to deal with indiscipline among Junior High Schools in Agona Swedru in the Agona West Municipality. The study was a quantitative study underpinned by the positivist paradigm and adopted the descriptive survey design. The study was undertaken in the Agona Swedru township in the Agona West Municipality of Ghana. Selected Junior High school students formed the sample of the study. Purposive sampling and simple random sampling were used to sample 120 students for the study. The questionnaire was employed for data gathering. Data were analyzed descriptively using frequencies and percentages. It emerged from the study that predominant forms of indiscipline behaviours were related to the following; leaving the school grounds, physical aggression, disturbing others, inappropriate use of school material, out-of-seat behaviour such as moving, noncompliance with teacher’s directives. The study revealed that the causes of indiscipline behaviour were school size, home factors, individual factors, family factors, gender and ethnicity, school factors, societal factors, and peer group pressure. The study showed that indiscipline behaviours result in low academic performance, breeds undesirable student behaviour, and dropping-out of school. The study therefore recommends that the Agona educational directorate, the Agona District assembly, the authorities of the selected schools and the various administrative staff should collaborate with the guidance and counselling coordinators to organise programmes focused on the forms of indiscipline exhibited by the students to effectively equip them to deal with the everyday indiscipline behaviours in the school. Article visualizations:

Mandarin peel as an auspicious functional filler for polymer composites

This work describes the mandarin peel (MP) application as a waste filler for high-density polyethylene (HDPE) composites. The main goal was to investigate the impact of filler’s essential oils, which include multiple terpenes and terpenoids, on the processing, physicochemical, mechanical and thermal properties, as well as color and volatile organic compounds emissions from the composites with different filler content (1-10 wt%). At small loadings, MP can be considered an efficient filler for wood-polymer composites, enhancing their flowability, tensile strength and thermal stability. Besides, it may act as colorant and aroma compound for polymer materials, and enhances the termooxidative resistance of composites. The oxidation induction time was elongated from 20 min for HDPE up to 62 min for the composites with 10 wt% of filler. The obtained research results allow application of the MP not only in the production of highly-filled composites, but also as an additive that significantly enhances the composites’ performance at low concentrations.

Effect of Deformation Rate on the Elastic-Plastic Deformation Behavior of GH3625 Alloy

GH3625 alloy is a typical polycrystalline material. The mechanical properties of a crystal within the alloy depend on the single crystal properties, lattice orientation, and orientations of neighboring crystals. However, accurate determination of single crystal properties is critical in developing a quantitative understanding of the micromechanical behavior of GH3625. In this study, the effect of deformation rate on the elastoplastic deformation behavior of GH3625 was investigated using in situ neutron diffraction room-temperature compression experiments, EBSD, and TEM. The results showed that the microscopic stress–strain curve included elastic deformation (applied stress, σ ≤ 300 MPa), elastoplastic transition (300 MPa 350 MPa) stages, which agreed with the mesoscopic lattice strain behavior. Meanwhile, the deformation rate was closely related to the crystal elastic and plastic anisotropy. The results of the lattice strain, peak width, and intensity reflected by the specific hkl showed that the deformation rate had little effect on the elastic anisotropy of the crystal, but had a significant effect on the plastic anisotropy of the crystal. With the increase in the deformation rate, the high angle grain boundaries gradually changed to the low angle grain boundaries, and the proportion of twin boundaries gradually reduced. Also, the grains transformed from uniform deformation to nonuniform deformation. Moreover, with the increase in deformation rate, the total dislocation density (ρ) of the alloy first decreased and then increased, whereas the geometrically necessary dislocation density (ρGND) monotonically increased, and the statistically stored dislocation (SSD) density (ρSSD) monotonically decreased. Meanwhile, the abnormal work hardening behavior of the sample at a deformation rate of 0.2 mm/min was mainly related to the SSD generated by uniform deformation. Additionally, the contribution of dislocation strengthening and TEM observation confirmed that the dominant deformation of GH3625 was dislocation slip, and its work hardening mechanism was dislocation strengthening.

A semi-analytical FE method for the 3D bending analysis of nonhomogeneous orthotropic toroidal shells

Based on Reissner's mixed variational theorem (RMVT), the authors develop a semi-analytical finite element (FE) method for a three-dimensional (3D) bending analysis of nonhomogeneous orthotropic, complete and incomplete toroidal shells subjected to uniformly-distributed loads. In this formulation, the toroidal shell is divided into several finite annular prisms (FAPs) with quadrilateral cross-sections, where trigonometric functions and serendipity polynomials are used to interpolate the circumferential direction and meridian-radial surface variations in the primary field variables of each individual prism, respectively. The material properties of the toroidal shell are considered to be nonhomogeneous orthotropic over the meridian-radial surface, such that homogeneous isotropic toroidal shells, laminated cross-ply toroidal shells, and single- and bi-directional functionally graded toroidal shells can be included as special cases in this work. Implementation of the current FAP methods shows that their solutions converge rapidly, and the convergent FAP solutions closely agree with the 3D elasticity solutions available in the literature.

Trigger finger in children with hurler syndrome - distribution pattern and treatment options.

Introduction: Mucopolysaccharidosis is a rare and congenital autosomal recessive lysosomal storage disorder of glycosaminoglycans. An enzyme defect leads to cell, tissue and organ dysfunction. Carpal tunnel syndrome and trigger finger are the results of mucopolysaccharid deposition.Material and methods: We are treating 6 patients with mucopolysaccharide associated trigger fingers in an interdisciplinary setting with the department of pediatric hematology and oncology at Hannover Medical School, where each patient is examined inter alia for symptoms of trigger finger annually.Besides an interview of the parents about abnormalities with regard to hand function, pain and/or neurologic symptoms the children are examined by palpation and by assessment of the active and passive range of finger motion.In the case of finger locking due to an impaired excursion of the flexor tendons in the A2 and A3 pulley region, we performed a trap-door incision technique for A2 pulley widening and a simple release of the A3 pulley.Results: In 6 patients 43 fingers were affected. The average age was 10 years. Pulley thickening was palpated in 19 fingers of to the left hand and 24 fingers of the right hand. In 7 fingers the A1 pulley was affected, in 28 fingers the A2 pulley and in 25 fingers the A3 pulley. The A4 and A5 pulley were not affected in any case. Trigger symptoms were seen in 13 fingers. Five of the 6 children were given an operation indication. In these cases we performed carpal tunnel release, release of Loge de Guyon, and trigger finger release, either in combination or alone. In all cases the procedure led to pain relief and functional improvement.Conclusion: The treatment of trigger fingers in children with mucopolysaccharidosis as a rare disease is challenging with regard to diagnostics and indication.The main treatment goal is pain relief and improvement of hand function.

Vibration analysis of FG cylindrical shell: Evaluation of Ritz-polynomial mixed with ring terms

Here the Rayleigh - Ritz method has been applied to derive the shell vibration frequency equation. This equation has been formed as an eigenvalue problem form. MATLAB software package has been utilized for extracting shell frequency spectra. Nature of materials used for construction of cylindrical shells also has visible impact on shell vibration characteristics. For isotropic materials, the physical properties are same everywhere, the laminated and functionally graded materials vary from point to point. Here the shell material has been taken as functionally graded material. Moreover, the impact of ring supports around the shell circumferential has been examined for the various positions along the shell axial length. These shells are stiffened by rings in the tangential direction. These ring supports are located at various positions along the axial direction round the shell circumferential direction. These variations have been plotted against the locations of ring supports for three values of exponents of volume fraction law. For three conditions, frequency variations show different behavior with these values of exponent law. The influence of the positions of ring supports for simply supported end conditions is very visible. The frequency first increases and gain maximum value in the midway of the shell length and then lowers down. The comparisons of frequencies have been made for efficiency and robustness for the present numerical procedure.

Masthead: Materials and Corrosion. 05/2021

Masthead: Materials and Corrosion. 05/2021

Dosimetric Comparison of IMRT with 3D-CRT Regarding Their Contribution to the Treatment Plan Optimization Using Rando Phantom with a Realistic Lung Cancer Radiotherapy Treatment Planning

Introduction: This study compared a three-dimensional conformal radiation therapy (3D-CRT) with a recently implemented intensity modulation radiation therapy (IMRT) technique performed in the irradiation of lung cancer. The objective of this study is to demonstrate the dosimetric advantages of IMRT in target coverage, dose homogeneity, and reducing toxicity. Material and Methods: Depth point doses were compared as calculated by the Varian Eclipse treatment planning system (TPS) on virtual created patient and experimentally measured by thermoluminescence (TL) dosimetry. For treatment planning the same lesion of the real case with different volumes and structures contouring details were created on Rando anthropomorphic phantom computed tomography (CT) data. Dose measurement was performed by calibrated thermoluminescent detectors. Results: The difference between experimental TL measured doses and calculated doses in both techniques show mean values of ~3% (IMRT) and ~1% (3D-CRT) for high dose (>0.55Gy) and ~7% IMRT and 6.5% (3D-CRT) for low dose (<0.55Gy). All IMRT optimized plans improved the heart (-28.3%), the spinal cord (-25.3%), and the left lung (-41.55%) sparing significantly, compared to the 3D-CRT plans. The optimized dose-volume histograms, the dose covering indices, and the dose profile across heterogeneity interfaces showed a significant improvement in dose conformity by IMRT. Conclusion: These findings demonstrate well that TL dosimetry when combined with suitable point dose measurement procedures can efficiently be used as an external and independent dose audit for the comparison between 3D-CRT and IMRT. IMRT with its dose-volume optimization algorithm can achieve a treatment plan quality in lung cancer radiotherapy unachievable by 3D-CRT.

Contents: Materials and Corrosion. 05/2021

Contents: Materials and Corrosion. 05/2021

Evaluating the effectiveness of using Merrill component display theory in performance and retention of the concept of fraction in kids grade elementary mathematics

Background The concept of fraction is one of the most difficult concepts of math in all levels of education. We aimed to investigate the effect of Merrill’s component display theory in the learning of students in math. Materials and Methods: In this case-control study, the number of students under investigation was 183 boys where 31 students were randomly selected as experimental group and 30 as control group. The concept of teaching was designed based on the teaching design pattern of Merrill’s Component Display Theory and based on which the students in experimental group was taught for 10 sessions of 45 minutes; control group also received the traditional teaching. After two months, students were post-tested for their performance by a 10-question exam taken from teacher’s guidebook. Then, after three more weeks, they were again post-tested to ascertin their retention of the topic. Data were analyzed using SPSS software version 16.0 Results: The T-test results showed that the mean of students in experimental group increased about four grades and from 13.9 reached to the significant number of 18 for the performance post-test with the standard deviation of 0.63. In retention, the mean of students changed from 15.4 to 15 which is not a lot. It also means that there was no significant difference between mean scores of retention of Merrill’ group and the scores of post-test Merrill’s group. It means that education materials used Merrill’s design have been positively effective. Conclusion Considering the findings, it can be stated that the Merrill’s component display theory has been effective in both performance and the retention of the students.

A new quasi-3D theory for the study of the bending of thick FGM's plates on elastic foundation

In this work, a new theory quasi-3D shear deformation is presented to analyze the bending of thick FGM (functionally graded materials) plates resting on Pasternak elastic foundations, whose number of variables is limited to five. The mathematical model used presents a new range of displacement based on indeterminate integral variables where the stretching of thickness is taken into account according to the power laws P-FGM, E-FGM and S-FGM. The compositions and volume fractions of the constituents in the FGM are supposed to change through the thickness. The principle of virtual work, as well as the Naiver method, is used in this study to solve the governing equations of motion to study these types of plates. The equilibrium equations according to the FG plate resting on Pasternak foundations are presented. The results obtained are compared to those determined by the other authors. It was observed from the comparative studies that quasi-3D theories that take into account thickness stretching effects can predict bending behavior more accurately than other theories.

The Effective Application of the Sustainable Development Concept in Construction Engineering - Case Study of the Construction Work of Modern Art Design Teaching and Training Centre by Shanghai Art & Design Academy

Manpower, machine, material, law, and environment are the five driving fact ors in a construction project; the joint workforce of real estate owners, project supervis ion, construction management, engineering design and other staff in the process of pro ject implementation imposes itself with a significant characteristics of looseness, due t o different units having their own interest demands. As an organizer, how to lead this “ talent-intensive” but loose technical team and promote their proactiveness; how to com plete the project under the premise of low consumption, high quality and high efficienc y, while the individual interests are also met remains a challenge. Therefore, on top of a comprehensive organizational structure, an effective construction management syste m and a strict quality supervision system/measures, team building and the psychologic al satisfaction of the needs of the staff remain key to the achievement of goals. In the p rocess of construction projects, to improve technology efficiency and meet the concept of sustainable development, green construction technology should be enhanced in app lications. On the premise of meeting the requirements of the project, it is essential to e nhance sustainability of the construction work, avoid excessive consumption of materi als, reduce construction costs, and to minimize the impact on the surrounding environ ment. The utilization of green construction technology can effectively achieve environ mental benefits, avoid excessive interference, and eventually improves the effectivenes s and environmental management level of the construction project.

Türkiye Şeftali Piyasasının Ekonomik Analizi ve Pazarlama Marjları

Çalışmada gıda sanayisine ham madde oluşturması, insan sağlığına sunduğu katkılar, enerji kaynağı ve gübre olarak kullanılabilmesi gibi özellikleriyle her geçen gün önemi artan şeftali piyasasının analizi amaçlanmıştır. Veri seti; TÜİK ve TOB istatistiklerinden temin edilen 2003-2017 yıllarına ait; üretici fiyatı, tüketici fiyatı, üretim, tüketim, ihracat, ithalat ve girdi fiyatlarına ilişkin verilerden oluşturulmuştur. Türkiye şeftali piyasasını analiz etmek amacıyla; arz ve talep fonksiyonları ile ilgili modeller tahmin edilmiş, pazarlama marjı ve zincirleme indeks hesaplamaları yapılmıştır. Regresyon tahmin sonuçları, üretim üzerinde; gübre fiyatlarının negatif yönlü, tarımsal işgücü ücretlerinin ise pozitif yönlü bir ilişki içerisinde olduğunu ortaya koymuştur. Talep üzerinde pozitif yönlü etkiye sahip faktörün nüfus olduğu belirlenmiştir. Reel fiyatlara göre; ortalama pazarlama marjı 0.60 TL kg-1, üreticinin eline geçen değer %53.92 olarak hesaplanmıştır. 2008-2011 yılları arasında ortalama %60.92 olan reel üreticinin eline geçen değerin 2017 yılına gelindiğinde %48.28 oranına gerilemesi; piyasada her geçen yıl elde edilen kazançtan üreticiye daha az pay düştüğünün göstergesidir. Üreticinin eline geçen değer artarken pazarlama marjının azalması hem üretici hemde tüketicinin lehine olacağı için, üreticilerin kooperatifler gibi pazarlama marjını azaltabilecek oluşumlara teşvik edilmesi önem taşımaktadır.

Faunistic Studies on the Genus Medon Stephens, 1833 (Coleoptera: Staphylinidae: Paederinae) in Turkey

In this study, 702 specimens belonging to the genus Medon Sephens were examined. The material was obtained from various field trips between 2010-2019 by using aspirator, sifter, pitfall trap, berlese funnel and MSS trap methods. As a result of the study, 15 of the 22 known species from Turkey were identified.Medon brunneus (Erichson, 1839), M. ferrugineus (Erichson, 1840), M. lanugo Assing, 2004 and M. subfusculus Fagel, 1969 from the Aegean Region, M. semiobscurus (Fauvel, 1875), M. abantensis Bordoni, 1980 and M. lamellatus Assing, 2004 from the Central Anatolian Region are reported for the first time. Besides, M. rufiventris (Nordmann, 1837) is recorded for the first time from both the Aegean and Central Anatolian Regions. In addition, many new locality records of the recorded species were presented. The distributions of all Medon species in Turkey were mapped.

Pendampingan Sistem Monitoring Absensi dan Pelanggaran Siswa Berbasis WEB dan BOT Telegram

The purpose of this web-based student attendance and student violation information system assistance and telegram bot is to make it easier for schools and student guardians to monitor disciplinary and student violation levels, so that the school can use it in this case SMP Nurul Jadid as evaluation material and consideration for making an Existing policies and regulations at Nurul Jadid Middle School, Telegram Bot are functioned to attend students by the teacher, so that the results of teacher input will be immediately recapitulated by the system, while for the website it is made using the CodeIgniter Framework to facilitate recording related attendance and student violations , while the mentoring process is carried out to the discipline and student affairs department so that later it will be disseminated to all teachers at Nurul Jadid Middle School.

Designing Sequence-Defined Peptoids for Biomimetic Control over Inorganic Crystallization

Crystallization defines what the world is all about, ranging from biomineralization in living organisms to various materials in our lives. During these processes, peptides and proteins involved in ...