bluuebunny/crossref_metadata_2025 huggingface dataset:
Obtaining doubled haploids of Cucurbita pepo L.
Authors: Domblides E. A. , Ermolaev A. S. , Belov S. N.
Published: September 2021

Doubled haploids have been widely used worldwide in breeding programs and fundamental research as valuable homozygous material for about 100 years. The species Cucurbita pepo L. are represented by a huge variety of forms, include highly productive vegetable crops and have a wide distribution in the world. Despite the great economic importance, the creation of effective protocols to ensure stable production of doubled haploids in this species remains an urgent task. DH plants are of interest not only because of the acceleration of the breeding process, but also because of the realization of the huge potential of gametoclonal variability inherent in this highly polymorphic species. In this review, we analyzed the main technologies used for obtaining doubled haploids in vegetable crops of C. pepo: parthenogenesis in situ stimulated by treated/irradiated pollen, gynogenesis in vitro (unpollinated ovule culture in vitro) and androgenesis in vitro (anther/microspore culture in vitro). An analysis is presented of the research carried out from the beginning of the discovery of haploid plants to the current advances and evaluation of the prospects in the field of DH plant production. The main critical factors influencing the efficiency of each technology and its individual steps are considered. The developed technology of doubled haploids obtaining using non-pollinated ovary culture in vitro is presented. This technology allows to obtain up to 55 embryoids per one cultivated ovary (28 embryoids/ 100 cultivated ovules) To introduce haploid technologies into the breeding process it is necessary to evaluate the obtained plants for ploidy level. The use of direct counting of chromosomes in apical cells may present a certain difficulty in this species due to their large number (2n=40) and their small size. Depending on the level of laboratory equipment, ploidy determination using flow cytometry of cell nuclei and counting the number of chloroplasts in stomatal guard cells in the epidermis of the abaxial side of the leaf may be more convenient methods. The prospects for the use of molecular markers for assessment for homozygosity in DH technologies used, including C. pepo, are discussed in the review.
Improving the soil fertility of agricultural lands in the Non-Black Earth Zone of the Russian Federation
Authors: Dubenok N. N. , Klimakhina E. V. , Matsyganova E. V.
Published: September 2021

Relevance. According to the Federal Law of 16.07.1998 No. 101-FZ (as amended on 05.04.2016) "On State Regulation of Ensuring the Fertility of Agricultural Land", owners, owners, users, including tenants of land plots are obliged to: carry out the production of agricultural products in ways that ensure the reproduction of the fertility of agricultural land, as well as excluding or limiting the adverse impact of such activities on the environment. Environment.Materials and methods.The research was carried out on a stationary field experience in the Podolsk district of the Moscow region in 2011-2012. On experience, five-floor crop rotation will be deployed in time: 1) oats; 2) barley with planted perennial herbs; 3) perennial herbs of the first year of use; 4) perennial herbs of the second year of use; 5) winter wheat. The plots were located in the upper part of the slope with a slope of 14% (weakly pitched) and in the lower part of the slope with a slope of 7% (gentle).Results. It was found that on average annually in the slope areas of the non-chernozem region soils lose from the layer 0-40 cm with a surface runoff of phosphorus 0.7-6.0 kg / ha, potassium 2.3-28.9 kg / ha, calcium 7.3-45.8 kg / ha. With anti-erosion methods of tillage on a slope with a steepness of 7%, the migration of chemical elements was 2.2 times less compared to similar options on the slope with a steepness of 14%. Surface runoff redistributes substances along the length of the slope, therefore, it is necessary to take this into account during chemical reclamation of the slopes soils and carry out differentiated application of fertilizers and lime. After chemical analysis of the arable layer of soil, it turned out that the maximum content of humus, mobile forms of phosphorus and exchange potassium is noted in the lower part of the slope, which is associated with the processes of washing and alluvium of the soil.
Creation of an interspecific hybrid of Capsicum annuum L. and C. frutescens L. using biotechnological approaches
Authors: Dzhos E. A. , Shumilina D. V. , Pyshnaya O. N. , Mamedov M. I. , Baikov A. A. , Matyukina A. A.
Published: September 2021

Relevance. Pepper is a common crop both for fresh consumption and for the preparation of spices. Recently, along with the increasing popularity of C. annuum L. pepper, there is increasing interest in other species of this genus, which have a number of breeding and important properties. The most important method of enriching the gene pool of cultivated plants is distant hybridization, through which valuable traits are transferred from wild species to cultivated ones. The development of a new variety is a lengthy process, stretching over several years. In this regard, breeders have faced the challenge of obtaining pure lines to create a pepper hybrid with desired properties by applying modern biotechnological methods that will accelerate this process. One of them is the method of microspore culture, which allows mass production of haploid plants, reducing the time for creating constant parental lines.Material and methods. The aim of the work was to create an interspecific hybrid of hot pepper (C. annuum L. x C. frutescens L.) with high ornamental properties, a complex of economically valuable traits, with good taste qualities. The research was carried out in the film greenhouse of FSBSI FSVC in the Moscow region. The research material was a variety population of hot pepper Capsicum frutescens Cz-544-14, used as a paternal line, which was heterogeneous, and a pure line of C. annuum L. (Pb-551) created by classical breeding.Results. The pepper hybrid F1 Christmas bouquet was created as a result of hybridization of species parental forms obtained by different methods (biotechnological and classical). To accelerate the production of an aligned paternal form of C. frutescens L., the technology of doubled haploids through microspore culture was used. As a result, doubled haploid plants meeting the planned model (compact low habit, purple fruit colouring in technical ripeness and red in biological ripeness) were obtained. The resulting hybrid combined all the necessary economic features: high ornamentality, compactness, bouquet arrangement of fruits, high taste and aroma. Thus, the use of remote interspecific hybridization in the breeding process in combination with biotechnological approaches can accelerate the production of new forms of hot peppers that meet the demands of the market.
Assessment of water footprint of vegetable crops
Authors: Fedosov A. Y. , Menshikh A. M. , Ivanova M. I.
Published: September 2021

Relevance. Agricultural production is the main consumer of water. Globally, about 70% of fresh water is annually used for agricultural (food and non-food) production. Nearly 40% of the world's food supply comes from irrigation. Globally, the scarcity of irrigation water due to competition between industry and urban consumption threatens food security. Future population growth, income growth and changes in nutrition are expected to increase demand for water. The rate of warming in Russia since the mid-1970s about 2.5 times the global average. The highest rate of temperature increase occurs at high latitudes. The entire territory of Russia is subject to warming, both as a whole for the year and in all seasons. Water Footprint Accounting (WF), proposed by the Water Footprint Network (WFN), has the potential to provide important information for water management, especially in water-stressed regions that rely on irrigation to meet food needs.Methodology. The purpose of this systematic review was to collate and synthesize available data on global water use in vegetable production. Searched online databases covering the areas of environment, social sciences, public health, nutrition and agriculture: Web of Science Core Collection, Scopus, OvidSP MEDLINE, EconLit, OvidSP AGRIS, EBSCO GreenFILE, and OvidSP CAB Abstracts. The search was conducted using predefined search terms that included the concepts of "vegetable crops" and "water footprint".Results. This article provides a brief overview of the vegetable growing water footprint and the sustainability of the blue water footprint. In general, a high green or overall (green + blue) WF may indicate that the vegetable crops are having low yields or inefficient water use. Low green and high blue WF indicate inefficient use of rainwater, which can lead to overexploitation of surface and groundwater. The water footprint can be considered a good economic ergometer, showing the level of water consumption required to obtain a certain vegetable product, whether it brings economic benefits or not, beneficial to society or not.
New technologies of cultivation of watermelon as a key to development of the melon industry
Authors: Koleboshina T. G. , Varivoda E. A. , Suslov P. P.
Published: September 2021

Relevance. The appearance on the market of water-soluble fertilizers, growth regulators, biological products requires a detailed study of these drugs to determine their effectiveness in increasing yields and optimizing costs. Therefore, the issue of developing environmentally friendly elements of the technology for growing varieties of table watermelon of different ripening periods with the use of new types and forms of water-soluble fertilizers becomes urgent.Materials and methods. The object of research is varieties of watermelon of domestic selection of early and medium ripening. The studies were carried out in 2018-2020 on the basis of the Bikovskaya cucurbits breeding experimental station (Bykovskiy district, Volgograd region). The methods of using the preparation Potassium Humate (liquid) were studied: Treatment of plants twice, Soaking the seeds before sowing. The passage of the main periods of plant growth and development, biometric parameters of plants, biochemical composition of fruits and productivity of table watermelon were determined. The purpose of the research: to determine the effectiveness of methods of using potassium humate (liquid) in increasing yields, to reveal their influence on the quality of table watermelon fruits of different ripening periods.Results. The experimental data obtained showed a fairly high efficiency of the use of humic fertilizer in the cultivation of table watermelon both in early-maturing varieties and in varieties of late ripening. The maximum yield of the late-ripening watermelon variety Ikar was obtained when using the preparation Potassium Humate for treating plants – 17.1 t/ha, which is 25.7% more than control. The same method of using the humic preparation was noted as the most promising in the early ripening variety of watermelon Triumph, where the yield exceeded the control values by 21.8% and the method of use was by 18.0% – soaking the seeds before sowing. Studies have determined that the use of the preparation Potassium Humate in the technology of growing table watermelon allows to obtain fruits of good quality with a content of nitrates significantly lower than the maximum permissible concentrations for this culture (MPC – 60 mg/kg).
Multimodal Counselling Therapy in the Management of Intimate Partner Violence among Married Couples in Owerri, Nigeria
Authors: Martha-Rose Chima Ify
Published: September 2021

The study investigated the effectiveness of Multimodal Counselling Therapy (MCT) in managing intimate partner violence such as all forms of wife battering, whether physical, psychological or emotional and marital rape. The study adopts pretest, post test, and control group quasi experimental design using a 2x2 method. Participants for the study included (10) identified married couples (20 subjects) experiencing domestic violence. They were randomly assigned into MCT treatment group and the control. Participants in the MCT group received treatment on multimodal therapy while the control group received placebo. Components of the MCT therapy include: empathy, rapport, anxiety management self-control, conflict resolution skills, effective communication skills, assertiveness and social skills training. Findings reveal that MCT was very effective in reducing intimate partner violence. It was also discovered that participants with higher educational level yielded more to treatment effects than their counterparts with low educational level. Recommendations were made based on the findings of the study.
An Analysis of the Behaviour of Prime Lending Rates in Sri Lanka
Authors: Perera W. S. Navin
Published: September 2021

The prime lending rate is the rate at which commercial banks loan funds to their most creditworthy customers, and hence, is usually lower than other market lending rates; reason why it is considered a “base or reference rate”. In Sri Lanka, the Central Bank of Sri Lanka (CBSL) has been compiling the Average Weighted Prime Lending Rate (AWPR) since January 1986. This paper examines the determinants of prime lending rates in Sri Lanka using weekly data from January 2004 to June 2013, while attempting to capture any asymmetries in prime rate changes to monetary policy decisions. Empirical evidence suggests that the prime rate is highly persistent, while the call money rate also remains a key determinant. However, domestic liquidity was statistically insignificant and even if it was, it has only a marginal impact in determining the prime lending rate. Furthermore, there is also evidence of asymmetric adjustment in AWPR.
A Comparative Analysis Based on Economic Factors of Students Emigration from South Asia
Authors: Khan Yasir , Hassan Taimoor , Yi Wang Ming , Gulzar Rahimullah
Published: September 2021

Economic instability and higher unemployment significantly increased the number of students migration from all over the world, particularly South Asian countries in the last decade. Growing number of international student migration to abroad for higher education and search for better economic opportunity. This study will determine the economic impact of students’ emigration from South Asian countries particularly Pakistan, India, and Bangladesh. A comparative analysis of the three border sharing countries have shown the long-term economic and political instability and a result of an economic and financial collapse in 2008, and also discuss how such an environment has affected student emigration from South Asia. This study is quantitative research using questioners as a tool to collect primary data, from the large sample size of 300 South Asian students studying in Chinses universities in China. This research work is based on two factors, 1) the deterioration of economic factors in Pakistan, India, and Bangladesh have changed the students’ perception to migrate abroad; 2) the study also reflected that majority of Pakistani, Indian and Bangladeshi students want to stay in the host country. The findings indicated that all the related variables have significantly positive, economic instability, higher unemployment, lower salary, political instability, and lower quality education system. The logit-probit regression models with these variables could predict the higher value of the variance in the overall student migration to abroad. Findings are relevant for academic institutions and government agencies interested in international education, student migration behavior, comparative data as well as strategic policies.
Energy – Growth Nexus- A Case of South Asian Countries
Authors: Hussain Saddam , Yu Chunjiao , Wan Liu
Published: September 2021

The relationship between energy consumption and economic growth is a hot issue in today's society. This paper aims to empirically verify the relationship between energy consumption and economic growth. This article analyzes the relation of energy consumption with the economic growth taking the case of South Asian countries (Afghanistan, Bangladesh, Bhutan, India, Pakistan, Sri Lanka, and Nepal) along with the macroeconomic determinants that affect the total economic growth – FDI growth, CPI rate and population growth in order to avoid omitted variable bias and misleading results. The time span of this study covers the period of 1980–2019. To examine the significant relation of these determinants and impact of energy consumption on economic growth, In-pooled regression, Fixed-effects, Bidirectional fixed effect, Random-effects, and GLS estimation regression model are used. The estimated results show a positive correlation of energy consumption and all other economic determinants with economic growth except CPI, where there is a negative correlation founded.
Organic Geochemistry and Source Rock Potential of Naokelekan Formation in Selected Wells, North Iraq
Authors: Ismael Jan I.
Published: September 2021

In this study, organic geochemical characteristics and potential of Upper Oxfordian–Lower Kimmeridgian aged bituminous shale beds in Naokelekan formation (North Iraq) were investigated by using TOC and pyrolysis analyses. The Total Organic Carbon (TOC) contents for the studied samples varying between from 0.46-21.33%, average 7.06% and Taq Taq-1 well as good hydrocarbon potential (0.85-1.66 %, with average of 1.06%), whereas Jk-1 well can be rated as an very good hydrocarbon potential from 1.04-4.16 %, with average of 2.15 %. The low Hydrogen Index (HI = 24-605 mg HC/g TOC) for Bj-1 well, (HI = 147-673 mg HC/g TOC) in the Jk-1 well while in Taq Taq-1 well (HI = 9-48 mg HC/g TOC) indicate that kerogen type for the vast majority of the studied samples is Type II/I for Bj-1 well and Type IV with few samples, Type of I and II kerogens in the Taq Taq-1 and Jk-1 well. Consequently most of the organic matter of Bj-1 and Jk-1 well tends to generate petrol, even though a small portion of them exhibit a tendency to generate gas. While all samples of Taq Taq-1 well tends to generate gas. The studied bituminous rock samples characterized by low Tmax (434-602 °C) for Bj-1,Taq Taq-1 (344-429 °C) and (419-602 °C) for Jk-1 well. These values show, in terms of potential of hydrocarbon generation, that the studied samples have a source rock potential of organic matter from immature to over mature. Additionally, the S1 hydrocarbon type values indicate no external contribution of migrated hydrocarbons to the bituminous rocks of the studied area.
Turkish EFL Teachers’ Perceptions and Practices of Foreign Language Assessment in Primary Education
Authors: Kirkgoz Yasemin , Pinar Babanoglu Muzaffer , Ağçam Reyhan
Published: September 2021

The present study aimed to investigate perceptions of EFL teachers working at state primary schools on core language skills, assessment types and question types used in assessing student’s foreign language development and proficiency during an academic year. Data were gathered from 56 EFL teachers working at 42 primary state schools in Turkey through a questionnaire comprising a variety of items to elicit their perceptions and applications of language assessment in the classes of 4th to 6th graders. Results obtained from frequency analyses indicated that the pen-and-paper tests, performance tasks, and in-class observation are the mostly used assessment tools, and that the selected response items are mostly employed question types in the tests, and that performance-based and communication-based assessment types are preferred more frequently than the traditional types in evaluating students’ success in learning EFL.
Distributed Leadership an Instrument for School Improvement: The Study of Public Senior High Schools in Ghana
Authors: Dampson Dandy George , Havor Felicia Mensah , Laryea Prince
Published: September 2021

The purpose of the study was to investigate the influence of distributed leadership in Public Senior High Schools (SHS) with regard to school improvement. Using the Explanatory Sequential Mixed-Method design, 92 teachers and 4 head masters and 4 assistant head masters were randomly and census sampled. Three research questions were formulated and were analysed using simple percentages, mean and constant comparative thematic approach. The study revealed that generally head and assistant head masters and teachers recognize the practice of distributed leadership style in the SHS that is they perceive distributed leadership as a shared leadership where everyone is considered as a leader and given leadership opportunities. The findings further revealed that traditional and rigid leadership structure, lack of shared responsibility amongst teachers, leaders fear to involve teachers were the dominant challenges of distributed leadership in the study area. The study concluded that majority of the head masters, assistant head masters and teachers are currently practicing the distributed leadership since the success of distributed leadership depends on whether the leadership is willing to relinquish power, and the extent to which staff embrace the opportunity to lead. Based on the findings and conclusion drawn for the study, it is recommended that leadership in public SHS develops strategies that allow all teachers who are capable and willing to get an opportunity to lead certain areas of the school.
Assessing Student Reflection in a Malaysian Classroom
Authors: Fung Marianne Estabella , Liu May Siaw-Mei
Published: September 2021

Studies into reflective thinking in education have proposed a link between reflection and transformative learning. It is thus important for classroom practitioners to be able to identify whether students are reflecting on the subject matter of an academic course that they are undertaking. To this end, reflective journals can provide valuable information regarding the emotional and cognitive processes of the students. This study seeks to identify the level of reflective thinking attained by final year university students in Sabah, Malaysia, who have enrolled in an English for Specific Purposes course. As a preliminary study of the population, degree students from MARA University of Technology Malaysia were sampled and their reflective journals were analysed. The classification was done using a modified coding scheme proposed by past key researchers to classify students into the three categories of non-reflectors, reflectors, and critical reflectors. The results of this study can provide useful insights to course instructors.
The Effect of Performing Reading Activities with Critical Reading Questions on Critical Thinking and Reading Skills
Authors: YILDIRIM Sefa , SÖYLEMEZ Yusuf
Published: September 2021

The 21st century individual should be able to access information and critically evaluate and interpret it. What creates this obligation is the information bombing and political and commercial perception management brought about by virtual networks, the media and globalization. Therefore, critical thinking and its sub-component, critical reading, are becoming more and more important because they are the assistants of the individual who has to distinguish right from wrong and the truth from propaganda in life and texts. The aim of this study is to reveal the effect of performing reading activities with critical reading questions developed by the researchers on critical thinking and reading skills, and to pave the way for further research in this area. Study sample consisted of 232 students of Ağrı Ibrahim Çeçen University in the academic year of 2016-2017. Participants were recruited using random sampling technique. This was a mixed design study. The qualitative dimension of the study was based on a screening model. Data were collected using document review and interview methods, and were analyzed using content analysis. The quantitative dimension of the study was based on a quasi-experimental model. Data were collected using a Critical Thinking Self-Evaluation Form and a Critical Reading Scale (pre-test-post-test) before and after a 7-week application. Data were analyzed using a statistical software package. T-test and ANOVA were used for analysis. Results show that reading activities with critical reading questions have a statistically significant effect on students’ critical thinking and reading skills. Qualitative data also support these results.
An Analysis of the Multi-Cultural Characteristics of the Pre-Service Teachers in Terms of the Values They Have
Authors: POLAT Suat
Published: September 2021

In this study, it was aimed to analyze the multi-cultural characteristics of the pre-service teachers and the values they have in terms of various variables, and it was aimed to determine the relationship between these values. Descriptive survey model, one of the quantitative research methods, was used in the study. The population of the study consisted of the pre-service teachers studying in different departments in the Faculty of Education, İbrahim Çeçen University of Ağrı in 2017-2018 academic years. The sample of the study consisted of 341 pre-service teachers selected with random sampling method. “Multicultural Personality Questionnaire” developed by Oudenhoven and Zee (2002) and adapted into Turkish by Polat (2009) and “Values Scale” developed by Dilmac et al. (2014) were used as data collection tool in the study. According to the results obtained from the study, it was determined that the value preferences of the pre-service teachers and their multicultural personality characteristics showed a significant difference in terms of gender, undergraduate program, educational background of the mother, having social media account and daily internet use variables; however, there was not a significant difference in terms of family structure, the place s/he grew up, educational background of the father and monthly income variables. As the data collection tools are formed of several sub-dimensions, the abstract does not include information about which groups are favored for the difference in the variables and in which sub-dimensions, but detailed information is given in the following sections of the study.
The Perception of Malaysian ESL Tertiary Level Students on the IELTS Test
Authors: Zahari Dhiya Amalina , Dhayaalan Jeremiah Dhayaalan Jackson
Published: September 2021

Currently, the most acknowledged test to qualify for overseas universities is the IELTS test which is referred to as the International English Language Testing System. It is implemented as an accreditation tool and is believed to be a reputable and trustworthy tool of language competence by tertiary institutions which employ its use. Regardless of the current attention received by IELTS today, the views and opinions of candidates sitting for the test have seldom been looked into. Thus, this research is focused on examining the perception of Kolej MARA Banting candidates on the IELTS test. Consequently, a 9 item questionnaire on perception was given to 20 participants prior to and after sitting for the IELTS test. The data gathered was evaluated using t- test analysis to investigate the comparative differences among the learners’ perception prior to and after sitting for the test. Results proclaimed that candidates obtained a notably more positive perception after the test. Hence, some implications are made for all stakeholders especially those learners who are planning to take the test, educational organizations that are overseeing IELTS preparatory programs, educators who aspire to train candidates in such programs and administers of the test.
Smart Schools an Innovation in Education: Malaysian's Experience
Authors: Mirzajani Hassan , Bayekolaei Mehraneh Delaviz , Kookandeh Meysam Rajaby , Rezaee Seyede Safoora Razzaghpoor , Kamalifar Ali Akbar , Shani Hassan Razaghi
Published: September 2021

According to the new environment created by the information period, training and learning new skills are being inevitable. Retraining the skills of group working to coordinate the information age has created special conditions for education. Smart schools are one of the strategies adopted by schools in response to today's modern needs. Smart schools are active for entrepreneurship, using modern methods to improve the quality of education, and training qualified people who at any time have the capability and efficiency of modern industry. The purpose of this study, is the use of ICT in Malaysian Smart School and comparing it with the Smart Schools in Iran. To conduct this study, library, documents, Web sites and electronic journals are available. The results of this study show that although there are significant differences between the education system and deployment of ICT in Iran with the standards in smart schools in leading countries like Malaysia, according to the original development of smart schools in Iran which has been adapted from Malaysia, recognizing the realities of this action in Malaysia, can be effective in the development of schools in the country and prevent indiscriminate development.
Seed Breaking Dormancy Technique and Growth of Screw Tree (Helicteres isora Linn.) Seedlings
Authors:   Fakultas Kehutanan, Institut Pertanian Bogor, Yulia Nazhira Firda , Supriyanto Supriyanto ,   Fakultas Kehutanan, Institut Pertanian Bogor, Prameswari Diana ,   Pusat Standarisasi Instrumen Pengelolaan Hutan Berkelanjutan, Badan Standarisasi Instrumen, KLHK
Published: September 2021

Screw tree is a shrub from family Malvaceae that has many benefits in pharmacy. Screw tree seed has very hard seed coat, so the seed must be treated before germination. The aim of this research was to assess the characteristic of fruit and seeds, effect of seed breaking dormancy, and effect of NPK fertilizer dosage on the growth of screw tree (Helicteres isora) seedlings. The results indicated that screw tree fruits belong to dry fruits with capsule form and has 5 follicles that has different direction. Screw tree seed is orthodox type that has 9 ̶ 36 seeds in one follicle with triangle and square shape. Germination technique in laboratory with soaking the seeds in hot water 100oC until the water cool for 48 hours treatment produced the best germination amounting to 65.0%. Germination technique in green house with soaking the seeds in hot water 100oC until the water cool for 24 hours treatment was the best germination amounting to 77.0%. Seedlings fertilized with 1 g NPK doses increased screw tree growth in diameter parameter of 6.35 mm and shoot-root ratio parameter of 3.9 compared to control.
Growth and Genetic Parameters of Mindi (Melia azedarach Linn.) Progeny Test in Parungpanjang Forest Research Station, Bogor
Authors:   Balai Penelitian dan Pengembangan Teknologi Perbenihan Tanaman Hutan, Danu Danu , Bramasto Yulianti ,   Balai Penelitian dan Pengembangan Teknologi Perbenihan Tanaman Hutan, Sudrajat Dede J. ,   Balai Penelitian dan Pengembangan Teknologi Perbenihan Tanaman Hutan
Published: September 2021

Mindi (Melia azedarach Linn., family Meliaceae) is a multipurpose forest tree species such as for furniture, vinier and plywood, otherwise the leaves for pesticide and medicine material. Mindi mostly cultivated in a community forest, especially in West Java. This study was aimed to assess the growth performance and genetic parameter of the progeny test of mindi at Parungpanjang Forest Research Station, Bogor, West Java. The progeny test was established by using a randomized complete block design, consisting of 6 blocks and 73 families and each family consisting of 4 trees row-plot. The survival at 7 years old was 57.48%, height was 7.15 m and diameter is 8.59 cm, in average. The height and diameter growths among families showed a significantly different. The best family growth in height and diameter were Sumedang-31 and Bogor-18 families, respectively.The individual and family heritabilities for both stem diameter and tree heght characters were stil relatively low, with the higher family heritability value than individual heritability. The genetic correlation between total height and stem diameter of 0.57 indicates a strong correlation between the traits.
Quasi-Static Compliance Calibration of Serial Articulated Industrial Manipulators
Authors: Theissen Nikolas Alexander , Gonzalez Monica Katherine , Barrios Asier , Archenti Andreas ,   Manufacturing and Metrology Systems Division, Department of Production Engineering, KTH Royal Institute of Technology 68 Brinellvägen, Stockholm 10044, Sweden,   IDEKO S.COOP, Elgoibar, Spain,   Industrial Dependability Division, Department of Sustainable Production Development, KTH Royal Institute of Technology, Södertälje, Sweden
Published: September 2021

This article presents a procedure for the quasi-static compliance calibration of serial articulated industrial manipulators. Quasi-static compliance refers to the apparent stiffness displayed by manipulators at low-velocity movements, i.e., from 50 to 250 mm/s. The novelty of the quasi-static compliance calibration procedure lies in the measurement phase, in which the quasi-static deflections of the manipulator’s end effector are measured under movement along a circular trajectory. The quasi-static stiffness might be a more applicable model parameter, i.e., representing the actual manipulator more accurately, for manipulators at low-velocity movements. This indicates that the quasi-static robot model may yield more accurate estimates for the trajectory optimization compared with static stiffness in the implementation phase. This study compares the static and apparent quasi-static compliance. The static deflections were measured at discretized static configurations along circular trajectories, whereas the quasi-static deflections were measured under circular motion along the same trajectories. Loads of different magnitudes were induced using the Loaded Double Ball Bar. The static and quasi-static displacements were measured using a linear variable differential transformer embedded in the Loaded Double Ball Bar and a Leica AT901 laser tracker. These measurement procedures are implemented in a case study on a large serial articulated industrial manipulator in five different positions of its workspace. This study shows that the measured quasi-static deflections are bigger than the measured static deflections. This, in turn, indicates a significant difference between the static and apparent quasi-static compliance. Finally, the implementation of the model parameters to improve the accuracy of robots and the challenges in realizing cost-efficient compliance calibration are discussed.
Kinematic Modeling of Six-Axis Industrial Robot and its Parameter Identification: A Tutorial
Authors: Alam Md. Moktadir ,   Graduate School of Advanced Science and Engineering, Hiroshima University 1-4-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8511, Japan, Ibaraki Soichi , Fukuda Koki
Published: September 2021

In advanced industrial applications, like machining, the absolute positioning accuracy of a six-axis robot is indispensable. To improve the absolute positioning accuracy of an industrial robot, numerical compensation based on positioning error prediction by the Denavit and Hartenberg (D-H) model has been investigated extensively. The main objective of this study is to review the kinematic modeling theory for a six-axis industrial robot. In the form of a tutorial, this paper defines a local coordinate system based on the position and orientation of the rotary axis average lines, as well as the derivation of the kinematic model based on the coordinate transformation theory. Although the present model is equivalent to the classical D-H model, this study shows that a different kinematic model can be derived using a different definition of the local coordinate systems. Subsequently, an algorithm is presented to identify the error sources included in the kinematic model based on a set of measured end-effector positions. The identification of the classical D-H parameters indicates a practical engineering application of the kinematic model for improving a robot’s positioning accuracy. Furthermore, this paper presents an extension of the present model, including the angular positioning deviation of each rotary axis. The angular positioning deviation of each rotary axis is formed as a function of the axis’ command angles and the direction of its rotation to model the effect of the rotary axis backlash. The identification of the angular positioning deviation of each rotary axis and its numerical compensation are presented, along with their experimental demonstration. This paper provides an essential theoretical basis for the error source diagnosis and error compensation of a six-axis robot.
Machining Performance of Robot-Type Machine Tool Consisted of Parallel and Serial Links Based on Calibration of Kinematics Parameters
Authors: Nagao Keisuke ,   Kanazawa Institute of Technology 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501, Japan, Fujiki Nobuaki , Tanaka Hiroto , Hayashi Akio , Yamaoka Hidetaka , Morimoto Yoshitaka
Published: September 2021

This study aims to calibrate the posture of a robot-type machine tool comprising parallel and serial links using a kinematics error model and verify the machining performance based on the measurement results of a machined workpiece calibrated with kinematics parameters. A robot-type machine tool (XMINI, Exechon Enterprises LLC) is used in this study. Typically, the performance required of a robot-type machine tool is not only dimensional accuracy but also the contour accuracy of the machined workpiece. Therefore, in this study, we first construct a forward kinematics model of a robot-type machine tool and identify the kinematics parameters used in it via spatial positioning experiments using a coordinate measuring machine. Based on the parameter identification results, we calibrate this robot-type machine tool and evaluate its machining performance in terms of the dimensional accuracy and contour accuracy of the machined workpiece.
Kinematic Tool-Path Smoothing for 6-Axis Industrial Machining Robots
Authors: Tajima Shingo ,   Tokyo Institute of Technology 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8503, Japan, Iwamoto Satoshi , Yoshioka Hayato
Published: September 2021

The demands for machining by industrial robots have been increasing owing to their low installation cost and high flexibility. A novel trajectory generation algorithm for high-speed and high-accuracy machining by industrial robots is proposed in this paper. Linear interpolation in the workspace and smooth trajectory generation at the corners are important in industrial machining robots. Because industrial robots are composed of rotational joints, the joint space has a nonlinear relationship with the workspace. Therefore, linear interpolation in the joint space, which has been widely used in conventional machine tools, does not guarantee linear interpolation in the actual machining workspace. This results in the degradation of the machining surface. The proposed trajectory generation algorithm based on the decoupled approach can achieve linear interpolation in the workspace by separating the position commands into Cartesian coordinates and the orientation commands into spherical coordinates. In addition, a novel corner smoothing method that generates a smooth and continuous trajectory from discrete commands is proposed in this paper. The proposed kinematic local corner smoothing generates a smooth trajectory by using a 3-segmented constant jerk profile at the corners in the joint space. The sharp corners can thereby be replaced by smooth curves. The resulting cornering error is controlled by varying the cornering duration. The simulation results demonstrate the effectiveness of the proposed kinematic smoothing algorithm in achieving linear tool motion in straight sections and in generating smooth trajectories at corner sections within the user-defined tolerance.
Vibration Mode and Motion Trajectory Simulations of an Articulated Robot by a Dynamic Model Considering Joint Bearing Stiffness
Authors: Sato Ryuta , Ito Yuya , Mizuura Shigeto , Shirase Keiichi ,   Department of Mechanical Engineering, Kobe University  1-1 Rokko-dai, Nada-ku, Kobe 657-8501, Japan,   DAIHEN Corporation, Kobe, Japan
Published: September 2021

Articulated robots are widely used in industries because they can perform manufacturing tasks with complicated movements. Higher speed and accuracy of motions are always required to improve the quality and productivity of products. The vibration characteristics of the robots are an important factor to achieve higher speed and accuracy motions. Robots are increasingly being used for machining. The vibration characteristics must also be considered when designing proper cutting conditions for the machining. To design control and cutting strategies for higher speed and accuracy motions or higher productivity of the machining process, it is effective to investigate the vibration characteristics of the robot and develop a mathematical model which can represents the vibration characteristics. The aim of this study is to investigate the vibration characteristics of an architectural robot and develop a mathematical model which can represent the dynamic behavior of the robot. To achieve this, vibration mode of an industrial architectural robot is analyzed based on measured frequency characteristics. According to the results of the modal analysis, it was clarified that the axial and angular stiffness of bearings of each joint of the robot has a significant impact on the vibration characteristics. Therefore, in this study, a mathematical model of the robot is developed considering the joint bearing stiffness. The mathematical model that also considers the kinematics of the robot, stiffness of reduction gears, control system for motors, and disturbance, such as friction and gravity, is introduced into the model. The control system is precisely modeled based on actual control algorithm in accordance with the implemented source codes. Although mass and inertia of the links are obtained from the 3D-CAD model, stiffness and damping parameters of the bearings and reduction gears are identified by matching the measured and simulated frequency responses. It has been confirmed that the model can adequately represents the vibration mode of the actual robot. Circular motion tests were performed to verify the model. Motion trajectories of the end effector were measured and simulated. As a result, it has been confirmed that the developed model is effective to analyze the dynamic behaviors.
High-Precision Mobile Robotic Manipulator for Reconfigurable Manufacturing Systems
Authors: Inoue Shinichi , Urata Akihisa , Kodama Takumi , Huwer Tobias , Maruyama Yuya , Fujita Sho , Shinno Hidenori , Yoshioka Hayato ,   Makino Milling Machine Co., Ltd.  2-3-19 Nakane, Meguro-ku, Tokyo 152-8578, Japan,   Tokyo Institute of Technology, Yokohama, Japan
Published: September 2021

The manufacturing industry has identified a new megatrend of mass customization, which is one of the essential goals of Industry 4.0. This megatrend requires the realization of manufacturing that can respond quickly and flexibly to various changing production requirements and ensure the achievement of various quality criteria. However, the manufacturing cannot be realized by conventional manufacturing systems in which reconfigurations need to be performed by skilled engineers. This paper proposes a new reconfigurable manufacturing system concept based on an ultra-flexible transfer system. Particularly, an autonomous mobile robotic manipulator, consisting of a high-performance automated guided vehicle module and a collaborative robotic manipulator module, represents a key component of the system concept. In this context, the focus is on the cooperative control between the modules of the autonomous mobile manipulator, which is essential for high-precision processes (e.g., machining, assembly, measurement, inspection), and its wide operating area. The experimental results confirm that the proposed cooperative control improves the positioning performance of the autonomous mobile manipulator, including the time required for positioning and the positioning accuracy.
Design, Fabrication, and Performance Analysis of a Vertically Suspended Soft Manipulator
Authors: Shoani Mohamed Tahir , Ribuan Mohamed Najib , Faudzi Ahmad Athif Mohd ,   Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia (UTHM) Parit Raja, Batu Pahat, Johor 86400, Malaysia,   School of Electrical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia,   Center for Artificial Intelligence and Robotics, Universiti Teknologi Malaysia (UTM), Kuala Lumpur, Malaysia
Published: September 2021

Soft continuum manipulators are comprised of flexible materials in a serpentine shape. Such manipulators can be controlled mechanically through tendons or pneumatic muscles. Continuum manipulators utilizing tendons are traditionally formed in a thick cross section, which presents limitations in achieving a high bending range as well as difficulties for storage and transportation. This study introduces a continuum manipulator comprised of two thin plastic bands and driven by a tendon to provide a bending action. The manipulator’s thin body form enables it to be rolled up for storage and transportation. Experimental results on different section lengths show the possibility of achieving a horizontal displacement of up to 34% of the bending-segment’s length, and a full closed-loop curvature for most segments. However, the results also indicated an elongation of the tip paths owing to gravity. These results, in addition to the manipulator’s flexibility and light weight features, confirm its suitability for applications in space and underwater environments.
Design Concept and Structural Configuration of Magnetic Levitation Stage with Z-Assist System
Authors: Takahashi Motohiro ,   Research and Development Group, Hitachi, Ltd. 832-2 Horiguchi, Hitachinaka, Ibaraki 312-0034, Japan
Published: September 2021

Magnetic levitation technology is expected to provide a solution for achieving nanometer-scale positioning accuracy. However, magnetic leakage limits the application of the magnetic levitation stage. To reduce magnetic density, motors should be installed at an appropriate distance from the table. This increases the axis interference between the horizontal thrust and the pitching, making it difficult to achieve stable levitation. In this study, a magnetic levitation stage system that has a unique motor structure fusing a gravity compensation function and pitching moment compensation is proposed. This compensation mechanism operates automatically using the passive magnetic circuit structure, ensuring that noises from the coil current and the timing gaps do not affect the driving characteristics and that neither wiring nor sensors are required. The basic characteristics were evaluated through the driving experiments, and the efficiency of the proposed gravity and pitching moment compensation system was demonstrated.