bluuebunny/crossref_metadata_2025 huggingface dataset:
Associations Between Language Difficulties, Peer Victimization, and Bully Perpetration From 3 Through 8 Years of Age: Results From a Population-Based Study
Authors: Øksendal Elise , Brandlistuen Ragnhild Eek , Wolke Dieter , Helland Siri Saugestad , Holte Arne , Wang Mari Vaage
Published: June 2021

Background and Purpose

Schoolchildren with language difficulties experience more peer victimization compared to their typically developing (TD) peers. Whether these children also bully their peers (bully perpetration) more than TD children is unclear. Furthermore, little is known about peer victimization and bully perpetration among preschool children with language difficulties and how it may be related to different paths of language difficulties. This study aimed to investigate associations between language difficulties, peer victimization, and bully perpetration from preschool to school age as well as the risk of peer victimization and bully perpetration for children with different developmental paths of language difficulties and mild language difficulties compared to TD children.

Method

The sample was drawn from the Norwegian Mother, Father and Child Cohort Study. Participants with completed questionnaires at 3, 5, and 8 years of age (n= 22,628) were included. Paths between latent variables of language skills at 3, 5, and 8 years of age, peer victimization at 5 and 8 years of age, and bully perpetration at 8 years of age were examined with structural equation modeling. Logistic regression was used to investigate peer victimization and bully perpetration for predefined paths of language difficulties.

Results

Poor language skills at 3 and 5 years of age were associated with peer victimization at 5 years of age. Poor language skills at 5 and 8 years of age were associated with peer victimization and bully perpetration at 8 years of age. The association between poor language skills at 5 years of age and bully perpetration at 8 years of age was stronger for girls. Persistent paths of language difficulties at 3, 5, and 8 years of age showed the highest risk of peer victimization and bully perpetration.

Conclusions

Language difficulties are associated with peer victimization and bully perpetration. The risk of peer victimization and bully perpetration differs according to different developmental paths of language difficulties from preschool to school age.
Design of uncertainty and disturbance estimator based tracking control for fuzzy switched systems
Authors: Sakthivel R. , Harshavarthini S. , Almakhles Dhafer J. , Kavikumar R.
Published: June 2021

In this paper, an uncertainty and disturbance estimator (UDE)‐based control is employed to ensure the finite‐time tracking and disturbance rejection performance for a class of Takagi–Sugeno fuzzy switched systems including additive time‐varying delays, unknown time‐varying uncertainties and disturbances. To be precise, the robust tracking performance is achieved by estimating unknown uncertainties and disturbances with the aid of low‐pass filter by means of appropriate bandwidth choice of the desired filter. Moreover, a new delay‐dependent finite‐time stability criterion is derived by employing fuzzy‐dependent Lyapunov–Krasovskii functional, extended Wirtinger's integral inequality and average dwell‐time approach to enforce the addressed system to track the given reference system within a finite period of time. Finally, the developed theoretical results are ensured by presenting the numerical examples with simulation results.
Selection of an IGCT for multilevel converters dedicated to high‐voltage direct current grid connection of offshore wind‐farms
Authors: Guedon Davin , Ladoux Philippe , Sanchez Sébastien , Cornet Sébastien , Stiasny Thomas , Winter Christian
Published: June 2021

Grid connection of remote offshore wind‐parks uses high‐voltage direct current technology and in order to reduce costs and losses and maximise profitability, semiconductor power losses must be minimised. To properly choose the semiconductors, it is necessary to estimate their losses for a large number of operating conditions. This article deals with a modelling approach to calculate power losses for many such operating conditions, based on measured semiconductor characteristics and the chosen multilevel modulation strategy. The case of the integrated gate‐commutated thyristor is considered because, for a given device rating, it is possible to select an integrated gate‐commutated thyristor benefiting from the best trade‐off between on‐state losses and turn‐off losses, thus minimising the power losses of the two end‐stations.
Simulating the transport of relativistic electrons and magnetic fields injected by radio galaxies in the intracluster medium
Authors: Vazza F. , Wittor D. , Brunetti G. , Brüggen M.
Published: June 2021

Radio galaxies play an important role in the seeding of cosmic rays and magnetic fields in galaxy clusters. Here, we simulate the evolution of relativistic electrons injected into the intracluster medium by radio galaxies. Using passive tracer particles added to magnetohydrodynamical adaptive-mesh simulations, we calculated the evolution of the spectrum of relativistic electrons, taking into account energy losses and re-acceleration mechanisms associated with the dynamics of the intracluster medium. Re-acceleration can occur at shocks via diffusive shock acceleration, and in turbulent flows via second-order Fermi re-acceleration. This study confirms that relativistic electrons from radio galaxies can efficiently fill the intracluster medium over scales of several hundreds of Myr and that they create a stable reservoir of fossil electrons that remains available for further re-acceleration by shock waves and turbulent gas motions. Our results also show that late evolution of radio lobes and remnant radio galaxies is significantly affected by the dynamics of the surrounding intracluster medium. Here, the diffusive re-acceleration couples the evolution of relativistic particles to the gas perturbations. In the near future, deep radio observations, especially at low frequencies, will be able to probe such mechanisms in galaxy clusters.
Assessment of high school textbooks addressing radiations
Authors: Economides S. , Karfopoulos K. , Mestousi E. , Founta P. , Carinou E. , Housiadas C.
Published: June 2021

Exposure to different types of radiation is an integral part of everyday life (e.g. cosmic radiation, radon, medical applications, cell phones, etc.). Therefore, the general public should adequately be informed on the issue from an early age in order to develop a realistic understanding of the associated risks and the necessary safety culture. In this respect, the quality of the related information provided in the school textbooks is of great importance. The present work demonstrates a quantified assessment of high school textbooks regarding the information on different radiation-related topics provided to students. The assessment was carried out based on an anonymous online survey with the participation of a total of 347 high school teachers. According to the results of the survey, the high school textbooks address radiation issues in a sparse, occasional, and fragmentary manner. Moreover, the results indicate that the quality of information they provide was judged as unsatisfactory in terms of scientific correctness, completeness, clarity-comprehensiveness and objectivity. Radiation protection and applications of non-ionizing radiation are the topics that are covered to a lesser extent in the textbooks and curricula evaluated.
Akute Infektionen der Hand – Ein Überblick über das Keimspektrum und gängige Antibiotika
Authors: Nischwitz Sebastian P. , Luze Hanna , Spendel Stephan , Girsch Werner , Koch Horst , Fuchsjäger Nina
Published: June 2021

Akute Infektionen der Hand können ein schwerwiegendes Krankheitsbild darstellen. Neben der chirurgischen Therapie ist die Etablierung einer antibiotischen Therapie in den meisten Fällen Mittel der ersten Wahl. Die häufigsten vorkommenden Keime sind Staphylococcus aureus sowie verschiedene Streptokokken. Bei Bisswunden ist zusätzlich Pasteurella multocida sehr häufig vertreten. Resistenzen gegen Antibiotika der entsprechenden Keime sind der publizierten Literatur zu Folge im (mittel-)europäischen Raum glücklicherweise selten, sodass Cephalosporine der 1. oder 2. Gruppe sowie Aminopenicilline mit Betalaktamaseinhibitoren die Mittel der Wahl darstellen. Insbesondere bei Begleiterkrankungen oder ungewöhnlicher Ätiologie der Infektion ist jedoch ein breiteres Keimspektrum zu erwarten, sodass eine Gewebeprobe zur Etablierung der optimalen antibiotischen Therapie wertvolle Informationen liefert. Infektionen der Hand sollten in jedem Fall mit besonderer Aufmerksamkeit engmaschig betreut werden, um gravierende Komplikationen zu verhindern. Dies sollte in enger Zusammenarbeit mit den beteiligten Fachdisziplinen sowie Physiotherapeuten erfolgen.
Spinal Pedicle Morphometry using Multidetector CT—An experience from the Indian Subcontinent
Authors: Sahu Samaresh , Yadav Ravinder , Sudhan Manoharan D. , Rao Akhilesk , Mohimen Aneesh
Published: June 2021

Introduction For safe pedicle screws placement, knowledge of pedicle morphometry is essential, because an inconsistency between pedicle width and the screw diameter may lead to severe complications like nerve, vessel or visceral injuries.

Objectives To study the spinal pedicle width and height of lumbar spine, using multidetector CT (MDCT), among the Indian population. To study the spinal pedicle angulation of lumbar spine, using MDCT, among the Indian population.

Method The study was conducted at a tertiary care multispecialty hospital. In the present study, a total of 321 patients were included, who underwent MDCT scan without contrast at our institution, over a period of 2 years, from May 2017 to May 2019. The study population (n = 321) was divided into different subgroups on the basis of the age. The data was taken from the workstation. Comparison was made separately between each subgroup.

Results In our subset of population, the 10 to 90 years age group, pedicle dimensions are as follow: The pedicle diameter from L1 to L5 is 4.46 to 11.92 mm. The pedicle height from L1 to L5 is 7.38 to 11.01 mm. The pedicle axial angulation from L1 to L5 is 22.27 to 36.08 degree. The pedicle lateral angulation from L1 to L5 is 16.12 to 22.47 degree.

Conclusion Knowledge of the pedicle morphometry (pedicle width, height and angulation) of lumbar spine will help the neurosurgeons standardize the size of pedicle screws which is required for spinal fixation surgery at various lumbar vertebra levels.
Buffering Effect of Spousal Support on Stress Levels in Mothers of Children with a Diagnosis of Autism Spectrum Disorder in Kerala, India
Authors: Jose Prinu , Sundaram Soumya , Varma Ravi Prasad
Published: June 2021

Objectives Bringing up a child with the diagnosis of autism spectrum disorder (ASD) can be highly stressful. This study aimed to assess perceived stress, level of spousal support, emotion-focused coping styles, and other potentially associated factors among mothers accompanying children diagnosed with ASD for care from selected institutions in Kerala, India.

Materials and Methods Consenting parents accompanying children to therapeutic programs in selected institutions were administered a semi structured interview schedule incorporating questions of the vernacular version of the Perceived Stress Scale (PSS-10), emotion-based coping strategies, spousal support in care of the child diagnosed with ASD, and possible-associated factors. Since internal consistency of stress and coping questionnaires were low, principal component analysis was used to extract composite variables with reasonable psychometric characteristics for stress and coping.

Statistical Analysis Ordinal logistic regression was performed with a three-level stress category as the outcome variable.

Results High stress was significantly associated with low spousal support (adjusted odds ratio or AOR: 2.80; 95% confidence intervals or CI 1.28–6.11), having a completely dependent child (AOR 4.24 [95% CI 1.92–9.38]), and low acceptance levels (AOR 2.60 [95% CI 1.14–5.89]). Unlike mothers with high spousal support, mothers with low spousal support were likely to have difficulty in interacting with others (p = 0.02) and a low level of acceptance (p = 0.05).

Conclusion Spousal support is important to preserve psychological health in mothers of children diagnosed with ASD. Mothers with low spousal support may need interventions that help increase acceptance levels or decrease avoidant behavior.
Leprous Neuropathy: Observational Study Highlighting the Role of Electrophysiology in Early Diagnosis
Authors: Vijayan Beena V. , Dominic Maria R. , Nair Vijayan C.P.
Published: June 2021

Background Worldwide leprosy is a common cause of peripheral neuropathy. Electrophysiology is underutilized in its diagnosis.

Objective This study aims to evaluate the usefulness of electrophysiological study in the diagnosis of leprous neuropathy.

Materials and Methods Clinical and electrophysiological abnormalities of 36 histopathology proven leprosy patients from January 2015 to January 2017 were studied.

Statistical Analysis Proportions were compared by Chi-square test.

Results Total patients were 36. Thirty-four patients had abnormal electrophysiology and 34 had neurological deficits like weakness, sensory changes, and thickening. By clinical examination, multiple nerve involvement (motor weakness, sensory changes, and nerve thickening) occurred in 29, single nerve in 5, and no nerve involvement in 2. With electrophysiology, multiple nerve involvement (mononeuritis multiplex) was present in 32, single nerve in 2, and normal conduction parameters in 2. From the 36 patients, a total of 1,008 nerves were subjected to clinical examination and 132 were picked up clinically as affected, (13.1%). Electrophysiological study was done in 504 nerves, and 215 were found to be involved, (43%). Nerve abnormality detected by electrophysiology is significantly higher than clinical detection. (Chi-square =164.4054; p = 0.0000). Clinically, the most commonly affected nerve was unar (27) and the least affected was median (2) nerve. Electrophysiology detected 69% of nerves with demyelination and 35% of nerves with axonal features (mosaic pattern).

Discussion There was subclinical neuropathy with electroclinical dissociation, as evidenced by more abnormality in electrophysiology than clinical examination. The nerve involvement was mononeuritis or mononeuritis multiplex pattern, both clinically and electrophysiologically. Electrophysiology showed both axonal and demyelinating nerve involvement (mosaic pattern). All the three features are present in leprous neuropathy. In corollary, if a patient has these electrophysiological features, he should be thoroughly investigated for leprosy.

Conclusion Triple findings, such as subclinical neuropathy with electroclinical dissociation, mononeuritis multiplex, and mosaic pattern of demyelination and axonopathy, suggest leprous neuropathy
Incivility and danger: theorizing a Muslim undercaste in Europe
Authors: Becker Elisabeth
Published: June 2021

Positing Muslim positionality in Europe as an undercaste helps to make sense of how cultural stratification, rooted in associations with incivility, has resulted in deep and unrelenting inequalities experienced by diverse Muslims. Based on two years of ethnographic research with a Muslim community in Berlin as well as a survey of secondary research, this paper both theorizes and empirically showcases the process by which Muslims have become synonymous with incivility, and how this affects opportunities and inclusion across the educational, economic, residential, and private spheres. By drawing parallels with other instances of caste-based status differentiation in the West, specifically the Jewish experience in Europe and Black experience in the USA, it further illuminates how cultural stratification through associations with incivility (as a modern secular coding of impurity) that endures for generations functions in the contemporary world. Employing the concept of caste deepens the cultural turn that has replaced economic or legal explanations of Muslim marginality in Europe. And it awakens a dormant sociological vocabulary that allows for a more precise theoretical understanding of this empirical social phenomenon and thereby the possibilities—and limits—of pluralism in modernity.
3D printing in biomedical engineering: Processes, materials, and applications
Authors: Lai Jiahui , Wang Chong , Wang Min
Published: June 2021

Three-dimensional (3D) printing as a powerful manufacturing platform has been increasingly used in biomedical engineering over the past two decades. Such technologies greatly improve our ability to fabricate a variety of complex and customized biomedical products accurately, efficiently, economically, and with high reproducibility through layer-by-layer positioning of materials, biomolecules, or even living cells in the products. Despite the impressive progress of 3D printing in biomedical engineering, more and greater efforts are needed to develop new and much improved biomedical products via 3D printing. In particular, many challenges in 3D printing processes, materials, and applications must be addressed in order to make available high-quality products and novel products to millions of patients. Addressing these challenges requires the integration of advances in physics, materials science, engineering, biological sciences, and medicine. In this article, we provide a comprehensive and up-to-date review of 3D printing and its applications in the biomedical field. We systematically present and discuss 3D printing technologies, materials, cells, and applications that are associated with biomedical engineering. Additionally, 4D printing and bioprinting are reviewed. We give our analysis and put forward our views on the challenges for 3D printing in biomedical engineering and also possible future developments. It is apparent that 3D printing plays a more and more important role in biomedical engineering and can create a diverse range of high-value biomedical products. This comprehensive review can help to understand the current status and identify future directions of 3D printing in biomedical engineering, as well as moving 3D printing toward manufacturing newer and better biomedical products.
Safety culture to improve accidental event reporting in radiotherapy
Authors: Tramacere Francesco , Sardaro Angela , Arcangeli Stefano , Maggialetti Nicola , Altini Corinna , Rubini Dino , Rubini Giuseppe , Portaluri Maurizio , Niccoli Asabella Artor
Published: June 2021

Background and purpose. The potential for unintended and adverse radiation exposure in radiotherapy (RT) is real and should be studied because RT is a highly complex, multistep process, which requires input from numerous individuals from different areas and steps of the RT workflow. The ‘Incident’ (I) is an event the consequence of which is not negligible from the point of view of protection or safety. A ‘near miss’ (NM) is defined as an event that is highly likely to happen but did not occur. The purpose of this work is to show that through systematic reporting and analysis of these adverse events, their occurrence can be reduced. Materials and methods. Staff were trained to report every type of unintended and adverse radiation exposure and to provide a full description of it. Results. By 2018, 110 worksheets had been collected, with an average of 6.1 adverse events per year (with 780 patients treated per year, meaning an average incident rate of 0.78%). In 2001–2009, 37 events were registered (13 I and 24 NM), the majority of them were in the decision phase (12/37), while in 2010–2013, there were 42 (1 I and 41 NM) in both the dose-calculation and transfer phase (19/42). In 2014–2018, 31 events (1 I and 30 NM) were equally distributed across the phases of the RT process. In 9/15 cases of I, some checkpoint was introduced. Conclusion. The complexity of the RT workflow is prone to errors, and this must be taken into account by encouraging a safety culture. The aim of this paper is to present the collected incidents and near misses and to show how organization and practice were modified by the acquired knowledge.
Rotation by deformation and time-crystalline dynamics of cyclopropane molecule
Authors: Peng Xubiao , Dai Jin , Niemi Antti J
Published: June 2021

A deformable body can rotate even with no angular momentum simply by changing its shape. Here the first all-atom level molecular dynamics example of this phenomenon is presented. For this the thermal vibrations of individual atoms in an isolated cyclopropane molecule are simulated in vacuum and at ultra-low internal temperature values. When the molecule is observed stroboscopically, at discrete equidistant time steps, the random thermal vibrations of the individual atoms become self-organized into a collective oscillatory motion of the entire molecule. The period of oscillation is emergent and intrinsic to the molecule so that this self-organization bears resemblance to a driven time crystal. The oscillation period increases in a self-similar manner when the length of the stroboscopic time step is increased. In the limit of very long stroboscopic time steps the entire molecule can then rotate in an apparent uniform fashion, but with no angular momentum. It is proposed that the observed behavior is universal in the case of triangular molecules. Moreover, it is shown that the emergent uniform rotation without any angular momentum, can be described in an effective theory approach as an autonomous Hamiltonian time crystal. The emergent oscillatory motion appears to be highly sensitive to temperature. This proposes that potential applications could be found from the development of molecular level detector to sensor and control technologies.
Effects of classical random external field on the dynamics of entanglement in a four-qubit system
Authors: Fosso Edwige Carole , Nya Fridolin Tchangnwa , Kenfack Lionel Tenemeza , Tchoffo Martin
Published: June 2021

We investigate the dynamics of entanglement through negativity and witness operators in a system of four non-interacting qubits driven by a classical phase noisy laser characterized by a classical random external field (CREF). The qubits are initially prepared in the GHZ-type and W-type states and interact with the CREF in two different qubit-field configurations, namely, common environment and independent environments in which the cases of equal and different field phase probabilities are distinguished. We find that entanglement exhibits different decaying behavior, depending on the input states of the qubits, the qubit-field coupling configuration, and field phase probabilities. On the one hand, we demonstrate that the coupling of the qubits in a common environment is an alternative and more efficient strategy to completely shield the system from the detrimental impacts of the decoherence process induced by a CREF, independent of the input state and the field phase probabilities considered. Also, we show that GHZ-type states have strong dynamics under CREF as compared to W-type states. On the other hand, we demonstrate that in the model investigated the system robustness’s can be greatly improved by increasing the number of qubits constituting the system.
Theoretical study on the exciton dynamics of coherent excitation energy transfer in the phycoerythrin 545 light-harvesting complex
Authors: Cui Xue-Yan , Yan Yi-Jing , Wei Jian-Hua
Published: June 2021

The experimental observation of long-lived quantum coherence in the excitation energy transfer (EET) process of the several photosynthetic light-harvesting complexes at low and room temperatures has aroused hot debate. It challenges the common perception in the field of complicated pigment molecular systems and evokes considerable theoretical efforts to seek reasonable explanations. In this work, we investigate the coherent exciton dynamics of the phycoerythrin 545 (PE545) complex. We use the dissipation equation of motion to theoretically investigate the effect of the local pigment vibrations on the population transfer process. The result indicates that the realistic local pigment vibrations do assist the energy transmission. We demonstrate the coherence between different pigment molecules in the PE545 system is an essential ingredient in the EET process among various sites. The coherence makes the excitation energy delocalized, which leads to the redistribution of the excitation among all the chromophores in the steady state. Furthermore, we investigate the effects of the complex high-frequency spectral density function on the exciton dynamics and find that the high-frequency Brownian oscillator model contributes most to the exciton dynamic process. The discussions on the local pigment vibrations of the Brownian oscillator model suggest that the local heterogeneous protein environments and the effects of active vibration modes play a significant role in coherent energy transport.
Synthesis of α-Alumina Developed from Waste Aluminium using Precipitation Technique
Authors: Bin Mokaizh Aiman A. , Shariffuddin Jun Haslinda Binti Haji
Published: June 2021

The heated aluminium containers were added to a solution of 8.0 M H2SO4 solution, which eventually yielded a solution of Al2(SO4)3 after a series of stepwise precipitation reactions. Al2(SO4)3 was presented in large quantities of H2SO4 in the white semi-fluid solution; there were some unreacted aluminium parts. The solution was subjected to filtration and then mixed with anion in a ratio of 2:3, this resulted in the formation of a white layer Al2(SO4)3•18H2O. Thereafter, Al2(SO4)3•18H2O was calcined in an electric oven for 2 h at various calcination temperatures (500, 700, 900, 1100, and 1300°C). The mixtures were heated and cooled at a rate of 10°C/min. XRD was employed to investigate variations in temperature and determination of elemental accumulation of alumina produced. Ah(SO4)3•18H2O was due to a series of aluminium compositions produced from dehydration. All transitions from low temperatures to aluminium phases were converted to high-temperature α-Al2O3. The results obtained from X-ray disintegration showed that the α-Al2O3 phase was obtained at a reaction temperature of about 1150°C and above.
Epi-Partial Normality
Authors: Thabit S A S
Published: June 2021

The main aim of this work is to study a new version of normality called epi-partial normality, which lies between epi-almost normality and epi-mild normality. A space (X, T) is called an epi-partially normal space if there exists a topology T’, which is coarser than T, such that (X, T’) is Hausdorff partially normal. In this work, we investigate this property and present some examples that illustrate the relationships between epi-partial normality and other weaker kinds of both normality and regularity. We show that this property is a topological, a semi regularization and an additive property. Some properties and relationships of epi-partial normality are presented and proved.
Optimization of nitric acid properties for chemical recycling of cadmium from spent Ni-Cd batteries
Authors: Saleh M M , Bamsaoud Salim F. , Barfed H M
Published: June 2021

Cadmium is poisonous to living species even at low doses. In the cadmium-nickel battery industry, cadmium is commonly associated with nickel and cobalt. In this paper, the experimental results revealed that in recovering cadmium from spent nickel-cadmium batteries, sulfuric acid was much less potent than nitric acid. The effect of nitric acid quantity, molarity, temperature, and recovery time are studied to improve the process of recovering cadmium from spent Nickel-Cadmium batteries. The optimum values of nitric acid quantity, molarity, temperature, recovery time, and wasted material are 70 ml, 5 M, 70°C, 180 min, and 2g respectively. The recovered materials were investigated using an x-ray diffractometer (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDX). An atomic absorption spectrometer (AAS) was used to analyze the chemical composition of the leached samples.
Review on Data Acquisition of Electrocardiogram Biometric Recognition in Wearable Smart Textile Shirts
Authors: Nawawi Muhammad Muizz Mohd , Sidek Khairul Azami , Dafhalla Alaa K Y , Azman Amelia Wong
Published: June 2021

Electrocardiogram (ECG) wearable smart textile shirt has widely been investigated due to its high flexibility, reusability, comfort, and the possibility of being used for home-based, real-life activities and real-time measurement. ECG smart textile shirt is an embedded textile sensor inside a cloth that can capture ECG data in more convenient ways and ease user-friendly, especially for continuous and long-term ECG data acquisition outside the laboratory environment. However, the current challenge with ECG smart textile shirt is the reliability and quality of data acquired by the wearable smart textile. This review will mainly focus on the research strategies in the early stages regarding data acquisitions in ECG smart textile shirt. It will introduce researchers’ data acquisition methods in the biometric recognition system using wearable ECG smart textile. The Scopus and Mendeley databases review may help future researchers consider different parameters, which affect the reliability and data quality when selecting data acquisitions strategies in a biometric recognition system using wearable ECG smart textile shirt.
Distribution of nutrients in surface seawater from the Aden coasts/Gulf of Aden, Yemen
Authors: Kasem Saleh Shaif Mohammed , Ahmed Al-Halmi Fursan Thabet
Published: June 2021

The concentrations of nutrients as well as some physico-chemical parameters were evaluated at the surface seawater of eight stations in Aden city coasts during winter 2019 and summer 2020. The results indicated that the concentration of nutrients were high in the study stations, exception the reference station which was far from the sources of pollution, where the domestic sewage effluents that discharge to sea. Seasonal variations showed that nitrite and nitrate concentrations in all stations were higher during winter (0.053 and 5.460 mg/L) compared to their corresponding values in summer which were 0.029 and 3.130 mg/L respectively. On contrast, seasonal distributions of phosphate and silicate exhibited significantly higher values in summer 0.746 and 1.004 mg/L compared to their corresponding values in winter, which were 0.451 and 0.881 mg/L, respectively. The results of the study confirm the importance of protecting Aden coastal waters from various pollutants, especially wastewater pollutants.

Recommendations: Maintaining and repairing the sewage network and reconnecting cities with Al-Arish station. The waste is not directly discharged to the sea until after it has been treated, provided it is safe. The application of legislation and regulations related to the protection of the marine environment.
Optimal prediction in isotropic spatial process under spherical type variogram model with application to corn plant data
Authors: Somayasa W , Sutiari D K , Sutisna W
Published: June 2021

A central problem in modelling of spatial data is the construction of an optimal prediction map of a numerical quantity or variable under study. In geostatistics this study is commonly called universal kriging. In this paper we study weighted universal kriging method in which a weight function is used for improving the efficiency of the predictor. We consider isotropic spatial process under a variogram function belongs to the parametric family of spherical type. The parameters of the postulated variogram model are estimated by applying ordinary least squares method in that the squared distance between the variogram model and the associated variogram sample is minimized. Numerical approximation for finding the solution of the least squares equations is conducted by using graphical approach. The application of the method to a corn plant data results in the kriging map of the maximum height that can be achieved by the corn plants planted over a rectangular farm land. This investigation result can in advance describe the map of the fertility level of the farm land where the corn have been planted.
Spectral Analysis and SARIMA Model for Forecasting Indian Ocean Dipole (IOD) and Rainfall in West Aceh Regency
Authors: El Furqany Nuwairy , Miftahuddin  , Setiawan Ichsan
Published: June 2021

Indian Ocean Dipole (IOD) in the Indian Ocean is one of the climatic phenomena that affects climate conditions in western Indonesia. West of Aceh Regency is one of the districts in Aceh Province which borders and faces the Indian Ocean directly, so it has a significant impact due to climate events caused by the IOD phenomenon. Analysis for examines the occurrence of climate phenomena is needed to minimize the adverse effects due to the IOD phenomenon. Spectral analysis by calculating the periodogram and the SARIMA model for forecasting historical data. The data used are monthly data on the Indian Ocean IOD index and rainfall in West of Aceh in the period January 2010 to December 2019. The purpose of this study was to determine the periodicity of the IOD index data and rainfall, get a model and obtain the results of forecasting the IOD index and rainfall, and see the relationship of IOD to rainfall in West of Aceh. The results obtained in the spectral analysis are the characteristics of changes in the IOD index tend to increase or decrease in the IOD index every 17 months and the characteristics of changes in rainfall in West of Aceh tend to increase or decrease in rainfall every 6 months. The best model for predicting IOD index data is the SARIMA model (2,1,3)(0,1,1)17. Forecasting for 2020 and 2021 tend to show a downward trend in 2020 and an upward trend in 2021. While the best model for predicting West of Aceh rainfall data is the SARIMA model (2,0.2)(0,1,1)6. Forecasting for 2020 and 2021 tend to experience high rainfall in April and October for each year. The relationship obtained by the IOD index to rainfall in West of Aceh is when the IOD index is in a positive phase, rainfall in the West of Aceh region tends to decrease. Conversely, when the IOD index is in the negative phase, rainfall in the West of Aceh region tends to increase.
Relationship of Rainfall and IOD Phenomena by using Spectral Analysis and SARIMA
Authors: Miftahuddin  , Furqany N E , Bakar M A
Published: June 2021

Rainfall is very essential for life and it has complexity process. To obtain the relationship between rainfall in time-spatial of Aceh region and the Indian Ocean Dipole (IOD) phenomenon, we used spectral-analysis and SARIMA model. Identification results show that the rainfall data monthly in Aceh Barat (ABR), Aceh Besar (ABS), Sabang (S) and Aceh Utara (AU) has a similar pattern. However, due to the sensitivity of the occurrence of the IOD, the ABR region has higher rainfall compared to ABS, S and AU regions. Rainfall in all regions observation has a peak time, namely at the end of the year (October-November-December). It has the negative peak of the IOD event occurred in September-2016 while the positive peak point occurred in October-2019. Overall, the normal phase occurred from January to April-2019. In peak season in ABR and ABS, the rainfall intensity increased. The results showed that the rainfall model in ABR and S has normal distribution, whereas in ABS and AU has nonnormal distribution. Furthermore, the rainfall model in ABR with SARIMA(2,0,2)(0,1,1)6 is the best model compared to model of three other regions with high accuracy forecasting.
A case study of an edge-magic total labeling of (a,b)-cycle books
Authors: Swita B , Rafflesia U , Susanti S , Andari F , Simanihuruk M
Published: June 2021

Suppose α and β be the order and size of a graph G respectively. A one-one function h which maps the set of vertices and edges of a graph G onto the integers 1, 2, 3, …, α + β such that h(u) + h(uv) + h(v) = c for any edge (uv) ε E(G) is called an edge-magic total labeling of If h(u) ε {1,2, …, α} for any uεV(G) then h is a super edge-magic total labeling of G. One of interesting research topic is super edge-magic total labeling of cycle book. A cycle book B(a, m, b, n, t) is made up from m copies of cycle Ca
and n copies cycle Cb
with a commont path Pt
. Super edge-magic total labeling of a cycle book B(a, m, b, n, 2) is still under investigation even for the case a = b This paper talk about a partial solution to this problem. We prove that a cycle book B(5, 2, 3, n, 2) has a super edge-magic total labeling for all positive integr n. In addition, we show that a cycle book B(5, 2, 3, n, 2) have an edge-magic total labeling for an integer n, 1 ≥ n ≥ 6.
Control design for tracking problem of the bilinear control system using observation matrix and pole placement
Authors: Mu’tamar Khozin , Naiborhu Janson
Published: June 2021

Bilinear control system is widely used, especially in the chemistry and engineering to describe chemical reactions and biological populations. Many of them are discussing about how to stabilize the system. In this paper, control design for tracking problem of the bilinear control system is presented. It is assumed that bilinear control system has full relative degree and the system is observable. Control design is divided into two stages. First, using observation matrix, tracking problem of bilinear control system transformed into stabilization problem of linear control system. Then, the linear control system is stabilized using static feedback control with pole placement. Examples are given to show controller performance.
On the characteristic of homomorphisms on cyclically ordered groups
Authors: Gozali S M , Rosjanuardi R , Yusnitha I
Published: June 2021

For cyclically ordered groups G, G’, the mapping f: G → G’ is called a homomorphism, if f is a homomorphism with respect to the group operation, and whenever x,y,z in G such that [x,y,z], and f(x), f(y), f(z), are distinct, then [f(x), f(y), f(z)]. In this paper, it will be given some conditions related to group homomorphisms.
Bifurcation analysis of epidemic model waning immunity
Authors: Fahdilla C , Putri A R , Haripamyu H
Published: June 2021

In this paper, we analyse the bifurcation of epidemic models. Those model is waning immunity. First, the stability of those system is analyzed by analyzing the stability of critical points. The threshold number that associated with the stability was determined. Later, the existence of bifurcation was analyzed. The result show that bifurcation exist and threshold number is considered as bifurcation parameter. Numerical simulation is given to confirm the analytical results by showing the graphic solutions and phase portrait.
Twisted Toeplitz Algebras of Cyclically Ordered Groups
Authors: Rosjanuardi R , Gozali S M , Yusnitha I
Published: June 2021

We consider the group ℤƗlex ℤ as a linear ordered abelian group, and we induce a cyclic order so that the group is cyclically ordered, and denote it as ℤƗCOG ℤ. Suppose σ is a 2-cocycle on the group ℤƗCOG ℤ. We construct an isometric representation of the semigroup (ℤƗCOG ℤ). This representation generates a canonical algebra which we call the twisted Toeplitz algebra of the cyclically ordered group ℤƗCOG ℤ.
Robust Counterpart Open-Capacitated Vehicle Routing Problem with Time Windows and Deadline (RCOCVRPTWD) Model in Optimization of Waste Transportation in Subdistrict Kalidoni, Palembang Using LINGO 13.0
Authors: Puspita F M , Melati R , Br Simanjuntak A S , Yuliza E , Octarina S
Published: June 2021

Robust Counterpart-Open Capacitated Vehicle Routing Problem with time windows and deadline (RC-OCVRPTWD) model which was formed and explained in this paper, is a model used to design solid waste control routes to minimize the distance and time needed for vehicles to complete waste transportation in Kalidoni Sub-District, Palembang. The completion of this route is expected to be able to overcome the occurrence of solid waste accumulation in Kalidoni District, Palembang that involved two characteristics the time that takes for the vehicle to across the route and the time needed to transport waste to the vehicle, which is called time windows. The second combination of time above is deadline. Waste that are transported every day are divided into working areas where the distance of temporary disposal to other disposal in one working area and the volume of waste transported will affect the length of deadline needed. This RC-OCVRPTWD model uses the LINGO 13.0 application to obtain optimal routes and deadlines. The results show that the working route for Kalidoni Sub-District in working area 1 is completed within 28.6 km and a deadline of 2 hours 51 minutes. In working area 2, is with a distance of 23.6 km and a deadline of 1 hour 42 minutes, and in working area 3 is with a distance of 38 km and a deadline of 3 hours 16 minutes.
Implementation of arc flow model incapacitated multi-period cutting stock problem with the pattern set up cost to minimize the trim loss
Authors: Octarina S , Septimiranti D , Yuliza E
Published: June 2021

Two-dimensional Cutting Stock Problem (CSP) is a problem in cutting raw materials where the trim loss is on two sides, namely the width and length sides. This research implemented the Arc Flow model incapacitated multi-period with set up cost to minimize the trim loss in the cutting of paper. The cutting patterns were generated by the Pattern Generation (PG) algorithm. Furthermore, it was formulated to a linear Arc Flow model where the constraints indicated the number of demands per item. The solution of the model was completed using the LINGO 13.0 application. The optimal solution of the Arc Flow model showed that the quantity demands for the second and third types of items were fulfilled. The maximum amount of inventory contained in the second type of item for the second period was 132,517 sheets. Excess inventory will become a surplus. Based on the arc flow model solution, it turned out that no trim loss was produced, or in other words, trim loss is equal to zero.
Modeling the Count Data of Public Health Service Visits with Overdispersion Problem by Using Negative Binomial Regression
Authors: Espinoza Eha , Saputri Ully , Hafiz Fadilah Faizal , Devianto Dodi
Published: June 2021

The count data of health service visits can be modeled into Poisson regression analysis, where there is no overdispersion assumption by looking at the comparison between mean and variance. The overdispersion test is performed by using the ratio of the sum of Pearson residuals over the number of degrees of freedom that must be less than one. The overdispersion problem can be corrected accurately by building mixture distribution where the parameter of Poisson distribution is made to have Negative Binomial distribution as the theoretical model. The data used in this study are the number of visits to public health service at Padang city as many as 460 data, where the predictor variables are age, gender, education level, occupation, income, home health status, individual health status, health insurance type, distance to health service, and diet type. The best model of negative binomial regression is selected by considering the values of AIC, BIC, Log-likelihood, and overdispersion tests that occur between the resulting models. The final result of this count data model with negative binomial regression fits better and overcomes the overdispersion problem with the significant variable is individual health status for this population, and it can be explained that the more individual has a history of having severe illness the more often the number of visits to the health service, meanwhile the other predictor variables have no effect to the number of visits.
The dynamics of rainfall and temperature on peatland in South Sumatra during the 2019 extreme dry season
Authors: Irfan M , Virgo F , Khakim M Y N , Ariani M , Sulaiman A , Iskandar I
Published: June 2021

During the extreme dry season of 2019 massive fires broke out on peatlands in South Sumatera. This study examines the dynamics of rainfall and temperature in the peatlands of South Sumatera in the 2019 dry season as one of the fire disaster mitigation efforts. The data used are in situ measurement data by the Peatland Restoration Agency’s measurement stations on two peatlands in South Sumatera. The results of this study indicate that rainfall in July until October 2019 was very minimal even in one of the study sites in August there was no rain. This shows that rainfall anomaly has occurred along with massive fires so that rainfall is possible to be used as one of the fire control parameters in peatlands. The lack of rainfall in South Sumatera during this period was due to the positive Indian Ocean Dipole phenomenon that occurred in the Indian Ocean. The results of this study also showed that temperature did not have a clear pattern of relationship with fire events on peatlands.
Macro and Micro Minerals Composition of Indian Scad (Decapterus russelli) From Mollucas Waters
Authors: Hadinoto S , Fasa L R , Smith H
Published: June 2021

Minerals have a very important role for the human body, fulfillment of mineral needs in humans is obtained by consuming food. One source of animal minerals is Indian scad. Indian scad has a mineral composition that the body needs. This study aims to determine the macro and micro minerals composition of Indian scad. Samples are grouped by body weight, then prepared and tested for macro minerals (Ca, K, Mg and Na) and micro minerals (Cu, Fe, Mn, Se and Zn). The results of grouping the Indian scad based on the average weight obtained by 3 (three) groups, namely group A (72.8 g), B (136.1 g) and C (222.2 g). Proportion of Indian scad has a 69% flesh, 18% head and bones, 13% viscera and gills, 1% blood and water. Macro mineral measurements in each group of fish obtained results: Calcium 40.353 mg/g (A), 37.559 mg/g (B) and 71.334 mg/g (C), Potassium 69.350 mg/g (A), 55.834 mg/g (B) and 67.146 mg/g (C), Magnesium 10.701 mg/g (A), 7.985 mg/g (B) and 11.550 mg/g (C) and Sodium 29.525 mg/g (A), 28.942 mg/g (B) and 29.072 mg/g (C). Micro minerals measurement results: Copper 0.119 mg/g (A), 0.046 mg/g (B) and 0.068 mg/g (C); Iron 0.363 mg/g (A), 0.204 mg/g (B) and 0.324 mg/g (C); Manganese 0.013 mg/g (A), 0.011 mg/g (B) and 0.014 mg/g (C); Selenium 0.464 mg/g (A), 1.007 mg/g (B) and 2.847 mg/g (C); Zinc 0.262 mg/g (A), 0.227 mg/g (B) and 0.431 mg/g (C). Indian scad flesh has a macro and micro minerals composition that varies depending on the body weight of the fish.
Preparation of Activated Carbon from Gnetum gnemon Shell Waste by Furnace-NaCl Activation for Methylene Blue Adsorption
Authors: Lelifajri  , Rahmi  , Supriatno  , Susilawati
Published: June 2021

A low-cost activated carbon from waste biomass has been yielded and applied for dye removal. Gnetum gnemon shell from local agriculture and waste biomass was used as a carbon source. The activated carbon powder was yielded after Gnetum gnemon shell waste heating in furnace at temperature of 400°C and it was then activated with NaCl. Parameter effects such as contact time and pH on methylene blue dye adsorption were evaluated. The optimum methylene blue dye adsorbed on prepared activated carbon was achieved at contact time of 20 minutes and pH 8. Langmuir isotherm model was appropriate to describe the dye adsorption by prepared activated carbon. In this study, a maximum absorption capacity (Qmax) of 62.5 mg g-1 was obtained which indicated a potential activated carbon-based adsorbent for dye adsorption.