bluuebunny/crossref_metadata_2025 huggingface dataset:
Imaging in Diagnosis of Systemic Sclerosis
Authors: Rutka Katarzyna , Garkowski Adam , Karaszewska Katarzyna , Łebkowska Urszula
Published: January 2021

Systemic sclerosis (SSc) is a connective tissue disease characterized by fibrosis in skin and internal organs, progressive vascular obliteration, and the production of autoantibodies. Diagnostic imaging is irreplaceable in both diagnosing and monitoring patients suffering from systemic sclerosis. In addition to routinely used methods, such as comparative X-ray of the hands or a contrast-enhanced examination of the upper gastrointestinal tract or chest, there is an array of less widespread examinations, with an emphasis on magnetic resonance imaging (MRI) and ultrasonography, not only in the evaluation of the musculoskeletal system. This article will review the various imaging modalities available for SSc imaging and assessment, focusing on their utility as tissue-specific diagnosis and treatment monitoring.
Efficient Exfoliation of Layered Double Hydroxides; Effect of Cationic Ratio, Hydration State, Anions and Their Orientations
Authors: Karthikeyan Jayakumar , Fjellvåg Helmer , Bundli Silje , Sjåstad Anja Olafsen
Published: January 2021

The exfoliation ability of nitrate based Mg1−xAlx(OH)2(NO3)x·mH2O layered double hydroxides (Mg-Al LDH) in formamide into single or multilayer nanosheets depends strongly on nitrate anion orientation and layer charge. Our systematic studies used materials that were likely to disclose differences with respect to anion type and their concentrations in the interlayer gallery. We assured to avoid any carbonate incorporation into the galleries for nitrate, chloride, iodide, and sulfate based Mg-Al LDHs. Furthermore, the comparative exfoliation experiments were conducted for fully hydrated samples with as similar particle morphology as possible. The exfoliation of nitrate Mg-Al LDH is far superior to similar clays with carbonate, sulfate, chloride, or iodide as charge balancing anions. Quantitative analysis of exfoliation yield for pre-treated, fully hydrated samples, shows an optimum composition for exfoliation into single nanosheets of around x ≈ 0.25, while double or triple layered sheets are encountered for other x-values. We observe a clear correlation between the expansion of the interlayer gallery due to progressing tilts of nitrate anions and water molecules out of the horizontal interlayer plane, suspension turbidity, and degree of exfoliation. The established correlations extends to nitrate Ni-Al LDH materials. We finally claim that morphology is a dominating parameter, with house-of-card morphology particles exfoliation far less than platelet-like particles. Hence, hydrothermal treatment may be favorable to enhance exfoliation yields.
Evaluation of Mode II Fracture Toughness of Hybrid Fibrous Geopolymer Composites
Authors: Abid Sallal R. , Murali Gunasekaran , Amran Mugahed , Vatin Nikolai , Fediuk Roman , Karelina Maria
Published: January 2021

This research aims to examine the fracture toughness of hybrid fibrous geopolymer composites under mode II. For this purpose, eight geopolymer mixtures were cast and tested to evaluate the influence of steel and synthetic fiber hybridization on mode II fracture response. The first mixture was plain and was kept as a reference, while steel, polypropylene and glass fibers were used in the rest seven mixtures. The first three of which were mono-reinforced with one of the three fibers, while the rest of the four were hybrids reinforced with combinations of steel and synthetic fibers. The Brazilian center notched disc and the double notched cube test configurations were used to evaluate the mode II fracture toughness of the eight mixtures. The results of the tests showed that steel fibers played the vital role in enhancing the fracture toughness, where the mixtures S1.6 and S1.3G0.3 showed the best performance. The results also showed that increasing the notch depth decreased the fracture toughness with an approximate linear decrement fashion. It was found that the use of double-notched cubes resulted in much higher fracture toughness than the Brazilian notched discs, where the ratio of normalized fracture toughness of the disc specimens to cube specimens was approximately 0.37 to 0.47. This is attributed to the concentration of stresses along one defined path in the disc specimens compared to the multi-path stresses in the cube specimens. In addition, the accompanied tensile stresses in the disc specimens may lead to a mode I fracture before the designed mode II fracture.
Effect of the Test Procedure and Thermoplastic Composite Resin Type on the Curved Beam Strength
Authors: Hron Robin , Kadlec Martin , Růžek Roman
Published: January 2021

The application of thermoplastic composites (TPCs) in aircraft construction is growing. This paper presents a study of the effect of an applied methodology (standards) on out-of-plane interlaminar strength characterization. Additionally, the mechanical behaviour of three carbon fibre-reinforced thermoplastic composites was compared using the curved beam strength test. Data evaluated using different standards gave statistically significantly different results. The study also showed that the relatively new polyaryletherketone (PAEK) composite had significantly better performance than the older and commonly used polyphenylensulfid (PPS) and polyetheretherketone (PEEK). Furthermore, considering the lower processing temperature of PAEK than PEEK, the former material has good potential to be used in serial aerospace production.
The Sorting Process as a Tool for Promoting the Demand of Heterogeneous Customers
Authors: Tavor Tchai , Gonen Limor Dina , Spiegel Uriel
Published: January 2021

The present study concerns product diversification. The products differ in size, shape, flavor, fat content, etc., so that the producer can more specifically modify the particular product to the unique requirements of nonhomogeneous customers. The mathematical model assumes diversified demands of nonhomogeneous consumers for an initial unsorted item. The sorting process generates a better match between customer requirements and the actual supply of sorted products. Thus, the implementation of sorting costs allows for an increase in customer demands by adopting product characteristics that are closer to customer needs and tastes. The study also considers the pricing policy for diversified products in order to determine if price discrimination is preferable for attaining the manufacturer’s goal of profit maximization.
Specific Antiproliferative Properties of Proteinaceous Toxin Secretions from the Marine Annelid Eulalia sp. onto Ovarian Cancer Cells
Authors: Rodrigo Ana P. , Mendes Vera M. , Manadas Bruno , Grosso Ana R. , Alves de Matos António P. , Baptista Pedro V. , Costa Pedro M. , Fernandes Alexandra R.
Published: January 2021

As Yondelis joins the ranks of approved anti-cancer drugs, the benefit from exploring the oceans’ biodiversity becomes clear. From marine toxins, relevant bioproducts can be obtained due to their potential to interfere with specific pathways. We explored the cytotoxicity of toxin-bearing secretions of the polychaete Eulalia onto a battery of normal and cancer human cell lines and discovered that the cocktail of proteins is more toxic towards an ovarian cancer cell line (A2780). The secretions’ main proteins were identified by proteomics and transcriptomics: 14-3-3 protein, Hsp70, Rab3, Arylsulfatase B and serine protease, the latter two being known toxins. This mixture of toxins induces cell-cycle arrest at G2/M phase after 3h exposure in A2780 cells and extrinsic programmed cell death. These findings indicate that partial re-activation of the G2/M checkpoint, which is inactivated in many cancer cells, can be partly reversed by the toxic mixture. Protein–protein interaction networks partake in two cytotoxic effects: cell-cycle arrest with a link to RAB3C and RAF1; and lytic activity of arylsulfatases. The discovery of both mechanisms indicates that venomous mixtures may affect proliferating cells in a specific manner, highlighting the cocktails’ potential in the fine-tuning of anti-cancer therapeutics targeting cell cycle and protein homeostasis.
Triple Negative Breast Cancer: A Review of Present and Future Diagnostic Modalities
Authors: Dass Sylvia Annabel , Tan Kim Liu , Selva Rajan Rehasri , Mokhtar Noor Fatmawati , Mohd Adzmi Elis Rosliza , Wan Abdul Rahman Wan Faiziah , Tengku Din Tengku Ahmad Damitri Al-Astani , Balakrishnan Venugopal
Published: January 2021

Triple-negative breast cancer (TNBC) is an aggressive breast type of cancer with no expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2). It is a highly metastasized, heterogeneous disease that accounts for 10–15% of total breast cancer cases with a poor prognosis and high relapse rate within five years after treatment compared to non-TNBC cases. The diagnostic and subtyping of TNBC tumors are essential to determine the treatment alternatives and establish personalized, targeted medications for every TNBC individual. Currently, TNBC is diagnosed via a two-step procedure of imaging and immunohistochemistry (IHC), which are operator-dependent and potentially time-consuming. Therefore, there is a crucial need for the development of rapid and advanced technologies to enhance the diagnostic efficiency of TNBC. This review discusses the overview of breast cancer with emphasis on TNBC subtypes and the current diagnostic approaches of TNBC along with its challenges. Most importantly, we have presented several promising strategies that can be utilized as future TNBC diagnostic modalities and simultaneously enhance the efficacy of TNBC diagnostic.
Fatigue Crack Growth Characteristics of 34CrMo4 Steel for Gas Cylinders by Cold Flow Forming after Hot Drawing
Authors: Xu Xiaojiao , Lu Chuanyang , Li Yuebing , Ma Xiakang , Jin Weiya
Published: January 2021

The fatigue crack growth (FCG) behavior of 34CrMo4 steel, a typical material for gas cylinders, has been investigated. Specimens were taken from the base material (BM) as well as the hot-drawn (HD) cylinder and cold-flow (CF) formed cylinder along the longitudinal and transverse directions. The FCG tests were conducted under different stress ratios for different materials and directions. The main purpose of this research was to explore the influences of the mechanical and thermal processes, sampling direction and stress ratio on the FCG behavior of 34CrMo4 steel. To further reveal the mechanism of crack propagation at different stages, the microstructures and fracture modes of FCG specimens were analyzed by scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD), respectively. The results showed that HD and CF materials exhibited better resistance to fatigue crack propagation than BM. The FCG rates of investigated materials can be accelerated by the increase in stress ratio. However, the sampling direction had little effect on the FCG rate. Finally, a driving force parameter (DFP) model was used to fit the experimental FCG data of three materials with different mechanical and thermal processes. A unified transition stage between the stable and unstable FCG stages of three materials under various experimental conditions was revealed by DFP model, playing an important role on the early warning of fatigue fracture for different types of 34CrMo4 steel.
Effect of Mechanical Surface Treatments on the Surface State and Passive Behavior of 304L Stainless Steel
Authors: Jaffré Kathleen , Ter-Ovanessian Benoît , Abe Hiroshi , Mary Nicolas , Normand Bernard , Watanabe Yutaka
Published: January 2021

The effect of dry grinding on 304L stainless steel’s passive behavior is compared to two other surface finishing (mechanical polishing down to 2400 with SiC emery paper and 1 µm with diamond paste, respectively). The characterization of the surface state was performed using scanning electron microscopy, transmission electron microscopy, 3D optical profilometer, and X-ray diffraction. Results indicate that each surface treatment leads to different surface states. The ground specimens present an ultrafine grain layer and a strong plastic deformation underneath the surface, while an ultrafine grain layer characterizes the subsurface of the polished specimens. Grinding induces high residual compressive stresses and high roughness compared to polishing. The characterization of the passive films was performed by electrochemical impedance spectroscopy and Mott–Schottky analysis. The study shows that the semiconductor properties and the thickness of the passive films are dependent on the surface state of the 304L stainless steel.
Effect of Exercise Intensity on Cell-Mediated Immunity
Authors: Suzuki Katsuhiko , Hayashida Harumi
Published: January 2021

Moderate-intensity exercise is considered to enhance immune function and to be useful for preventing acute upper respiratory infections and similar conditions. Many people practice low-intensity short-duration exercise with the expectation of a beneficial effect on immunocompetency. However, it is difficult to affirm the existence of definite evidence of such a benefit. In this article, we discuss the effects of low-intensity short-duration exercise on cell-mediated immunity, and contrast them to the effects of high-intensity and long-duration exercise. Whereas high-intensity exercise induces inflammation and reduces cell-mediated immune system function, low-intensity exercise does not appear to have a large effect on either inflammation or cell-mediated immune function. Low-intensity exercises such as walking and yoga, which are helpful to relieve stress, cannot be considered as harmful to the immune system. Although yoga was shown to impose fewer restrictions on breathing and physical strain, the evidence that yoga enhances cell-mediated immunity remains insufficient. Therefore, further studies are needed to examine the exercise mode that may be most effective for improvement of immune functions.
Quantification and Verification of Cardiorespiratory Fitness in Adults with Prehypertension
Authors: Bhammar Dharini M. , Chien Lung-Chang
Published: January 2021

Background: Low cardiorespiratory fitness is associated with increased risk of hypertension and atherosclerosis in adults with prehypertension. The purpose of this study was to quantify cardiorespiratory fitness and to examine the utility of supramaximal constant-load verification testing for validating maximal oxygen uptake (VO2max) attainment in adults with prehypertension. Methods: Eleven adults (four women) with prehypertension (22.5 ± 2.9 y; body mass index (BMI): 24.6 ± 3.2 kg·m2) underwent an incremental exercise test followed 15 min later by a verification test at 105% of maximal work rate on a cycle ergometer. Results: There was no statistical difference in VO2 between the incremental (2.23 ± 0.54 L·min−1) and verification tests (2.28 ± 0.54 L·min−1; p = 0.180). Only three out of eleven participants had a higher VO2 during the verification when compared with the incremental test. If the verification test had not been conducted, one participant would have been incorrectly classified as having low cardiorespiratory fitness based on incremental test results alone. Conclusions: Verification testing validates the attainment of VO2max and can potentially reduce the over-diagnosis of functional impairment (i.e., deconditioning) in adults with prehypertension.
Relationships between Logistics Performance and Aspects of Sustainability: A Cross-Country Analysis
Authors: Larson Paul D.
Published: January 2021

The purpose of this study is to investigate relationships between national logistics performance and dimensions of sustainability. A series of hypotheses are developed and tested using regression analysis of secondary data. The sources of data are the Sustainable Society Index (SSI) and the World Bank’s Logistics Performance Index (LPI). Fundamental aspects of social sustainability and well-being—a healthy, educated population, equality, good governance, and reasonable income distribution—are related to higher levels of logistics performance. In addition, while logistics performance is a driver of economic activity and success, it is also a contributor to environmental degradation in the form of harmful emissions. If economic growth is among a nation’s goals, its leaders are advised to support social well-being, along with technologies and practices for greater energy efficiency (and lower emissions) in transportation.
Evaluation of an Algorithm for Testis-Sparing Surgery in Boys with Testicular Tumors: A Retrospective Cohort Study
Authors: Kooij Cezanne D. , Hulsker Caroline C.C. , Kranendonk Mariëtte E.G. , Zsiros József , Littooij Annemieke S. , Looijenga Leendert H.J. , Klijn Aart J. , Mavinkurve-Groothuis Annelies M.C.
Published: January 2021

Aim: This study reports surgical treatment and its outcome for boys with a testicular tumor, in order to analyze the considerations of testis-sparing surgery (TSS) and investigate whether, in retrospect, treatment was according to a recently developed algorithm. Methods: We retrospectively reviewed boys with testicular tumors who underwent surgical treatment between January 2000 and June 2020 at the Wilhelmina’s Children’s Hospital and the Princess Máxima Center for Pediatric Oncology, The Netherlands. Medical records were searched for clinical characteristics and outcome. Results: We identified 31 boys (median age = 5.5 years) with a testicular tumor, 26 germ cell tumors (GCTs), four sex cord-stromal tumors, and one gonadoblastoma. Seventeen boys (median age = 1.5 years) had malignant and 14 (median age = 3.6 years) had benign tumors. Four boys with benign GCTs were treated with TSS, 25 with radical inguinal orchiectomy (RIO), and 2 with scrotal orchiectomy. No recurrence or testicular atrophy was reported. All boys with benign testicular tumors were treated as suggested by the algorithm, except for one boy treated with RIO. Conclusion: Retrospective analysis of surgical treatment of prepubertal boys with benign testicular tumors showed that TSS appears to be safe, and should be considered based on clinicoradiological data, in line with our algorithm.
Efficacy of a Turkey Herpesvirus Vectored Newcastle Disease Vaccine against Genotype VII.1.1 Virus: Challenge Route Affects Shedding Pattern
Authors: Palya Vilmos , Tatár-Kis Tímea , Arafa Abdel Satar A. , Felföldi Balázs , Mató Tamás , Setta Ahmed
Published: January 2021

The control of Newcastle disease (ND) highly relies on vaccination. Immunity provided by a ND vaccine can be characterized by measuring the level of clinical protection and reduction in challenge virus shedding. The extent of shedding depends a lot on the characteristics of vaccine used and the quality of vaccination, but influenced also by the genotype of the challenge virus. We demonstrated that vaccination of SPF chicks with recombinant herpesvirus of turkey expressing the F-gene of genotype I ND virus (rHVT-ND) provided complete clinical protection against heterologous genotype VII.1.1 ND virus strain and reduced challenge virus shedding significantly. 100% of clinical protection was achieved already by 3 weeks of age, irrespective of the challenge route (intra-muscular or intra-nasal) and vaccination blocked cloacal shedding almost completely. Interestingly, oro-nasal shedding was different in the two challenge routes: less efficiently controlled following intra-nasal than intra-muscular challenge. Differences in the shedding pattern between the two challenge routes indicate that rHVT-ND vaccine induces strong systemic immunity, that is capable to control challenge virus dissemination in the body (no cloacal shedding), even when it is a heterologous strain, but less efficiently, although highly significantly (p < 0.001) suppresses the local replication of the challenge virus in the upper respiratory mucosa and consequent oro-nasal shedding.
Climate-Environmental Governance in the Mexico Valley Metropolitan Area: Assessing Local Institutional Capacities in the Face of Current and Future Urban Metabolic Dynamics
Authors: Delgado Ramos Gian Carlo
Published: January 2021

This paper focuses on the evaluation of local institutional capacities for advancing climate-environmental governance in the Mexico Valley Metropolitan Area (MVMA). It starts with a brief contextualization of the MVMA, followed by an estimation of current and tendential urban inflows and outflows by 2050 with the objective of delineating the challenges and potential implications ahead. Next, an assessment of local climate-environmental institutional capacities is offered. For that, the methodology and main outcomes of the so-called ICI-CLIMA index is presented for 2019. A qualitative discussion continues in order to assert the challenges and opportunities for advancing a coordinated urban agenda for sustainability and resilience. Such discussion has been enriched with documental and other type of information gathered through field research in all of the 76 municipalities that comprise the MVMA. The paper concludes that, in addition to the limited current climate-environmental local capacities, there is a mismatch between them and both the level of climate vulnerability officially identified and the environmental challenges currently facing. Therefore, for coping with a tendential scenario of increasing urban inflows and outflows and their associated climate-environmental implications, MVMA governments will have to improve their capacities while advancing, at all levels of government, the coordination of climate-environmental agendas, and of the later with urban planning and development agendas.
An Examination of Social Media Practices that Improve Customer Satisfaction in the B2B Market in the ICT Sector in India
Authors: Moses Thelma , Peter Raja , Peter Vasanthi
Published: January 2021

Recent developments in Information and Communication Technology (ICT) have initiated significant transformation in the way in which B2B firms interact with existing and potential customers. These advancements have a profound impact on the marketing practices of firms. Social media is one of the most important information technology tools which have a transformative impact on business enterprises. It has dramatically influenced businesses and industries in this era. Social connectivity through this online platform has become a key to marketing in firms. Given the exponential increase in the use of social media, firms need to be present where their customers are in order to know the needs of their customers and to satisfy them. The use of social media as a component of a firms’ marketing strategy is widely recognised by marketing practitioners. Also, marketers have embraced the abilities of these online platforms to assist in marketing practices in firms. However, there is limited research that explores the influence of social media usage on customer satisfaction in the B2B sector. This study seeks to fill this gap and examines the influence of social media practices adopted by the ICT firms on customer satisfaction. A web based survey was used to collect data from a sampling frame of ICT firms in India. Analysis shows that social media practices have a positive and significant influence on customer satisfaction. This research makes a distinct contribution to social media literature. It addresses the gap in literature by providing an understanding of the effective use of social media for marketing purposes by the B2B firms in the ICT sector in India. It provides empirical evidence to support that these effective social media practices improves customer satisfaction in these firms.
Augmenting the Business Intelligence Lifecycle Model with Usability: Using eye‑Tracking to Discover the why of Usability Problems
Authors: Beelders T.R. , Kotzé J.E.
Published: January 2021

Humans and machines generate data at an alarming rate but still struggle to analyse and process this data fast enough. In order to meet this rising demand, business intelligence (BI) software firms are constantly incorporating new reporting or analytical functionalities in their software. At the same time, in order to be used optimally, they must ensure these features do not overwhelm users. There has however recently been cases where organisations, even after significant monetary investments, fail to realise the full potential of BI tools, sometimes reporting less than 20% utilisation. The purpose of this study was to investigate possible causes of the low utilisation and test the inclusion of a BI usability process. The study uses an off‑the‑shelf tool as a matter of convenience but proposes that including an empirical evaluation process as part of the BI design and development could increase BI adoption and usage. A small feasibility study was conducted to determine whether eye‑tracking is viable as a means of determining why the usability problems exist. Findings suggest that analysis of eye‑tracking data, together with traditional usability measures offer insight into how users solve problems and use the BI tool. Therefore, it will be a valuable aid in the design and testing of BI tools before release to enhance the usability therefore and potentially increase adoption and usage rates and should be included as a phase in the design and development lifecycle.
An Approach to Establishing Simultaneous Server-Side Connections for NFC/Bluetooth enabled Quiz Management Systems
Authors: Aqui Jedidiah , Hosein Michael
Published: January 2021

Near Field Communication is a set of communication protocols for communication between two electronic devices over a distance of 4cm or less and Bluetooth is a wireless technology standard used for exchanging data between fixed and mobile devices over short distances using UHF radio waves in the industrial, scientific and medical radio bands, from 2.402 GHz to 2.480GHz, and building personal area networks(PANs). Both these protocols facilitate wireless/ internet less communication between devices that have the capabilities. This paper seeks to further expand the concept and usage of these protocols via the examination of modifications made to a Quiz Management System. The Quiz Management System, which is a solution to further advance the notion of a smart classroom setup within the context of short-range wireless technologies has already seen iterations developed on both the NFC and Bluetooth side of things.
Why do we need to Introduce Temporal Behavior in Both Modern Science and Modern Computing, with an Outlook to Researching Modern Effects/Materials and Technologies
Authors: Vegh Janos
Published: January 2021

Classic science seemed to be completed more than a century ago, facing only a few (but growing number of!) unexplained issues. Introducing time-dependence into classic science explained those issues, and its consequent use led to the birth of a series of modern sciences, including relativistic and quantum physics. Classic computing is based on the paradigm proposed by von Neumann for vacuum tubes only, which seems to be completed in the same sense. Von Neumann warned, however, that implementing computers under more advanced technological conditions, using the paradigm without considering the transfer time (and especially attempting to imitate neural operation), would be unsound. However, classic computing science persists in neglecting the transfer time and is facing a few (but growing number of!) unexplained issues, and its development stalled in most of its fields. Introducing time-dependence into the classic computing science explains those issues and discovers the reasons for its experienced stalling. It can lead to a revolution in computing, resulting in a modern computing science, in the same way, as it resulted in modern science's birth.
Multi-Dimensional Rajan Transform
Authors: Thiagarajan K. , Prateek Manish , Govindarajan Ethirajan
Published: January 2021

In this paper, we describe the formulation of a novel transform called Multi-Dimensional Rajan Transform, which is an extension of Rajan Transform. Basically, Rajan Transform operates on a number sequence, whose length is a power of two. It transforms any sequence of arbitrary numbers into a sequence of interrelated numbers. As regards 2D Rajan Transform, there are two methods to implement it: (i) Row- Column method and (ii) Column-Row method. The 2D Rajan Transform obtained using the first method need not be the same as that obtained using second method. Similarly, one can implement 3-D Rajan Transform using the following approaches: (i) Row-Column-Depth approach, (ii) Row-Depth- Column approach, (iii) Column-Row-Depth approach, (iv) Column-Depth-Row approach, (v) Depth-Row-Column approach and (vi) Depth-Column-Row approach. This paper explains these approaches to implement two and three dimensional Rajan Transforms.
Selected Applications of Stimuli-Responsive Polymers: 4D Printing by the Fused Filament Fabrication Technology
Authors: Ahroni Y. , Dresler N. , Ulanov A. , Ashkenazi D. , Aviv M. , Librus M. , Stern A.
Published: January 2021

In the past few years four-dimensional (4D) printing technologies have attained worldwide interest and they are now considered the "next big thing". The aim of this research is to provide three selected examples of stimuli-responsive polymer (SRP) applications additively manufactured (AM) by the fused filament fabrication (FFF) technique. To that end, a CCT BLUE filament of thermo-responsive polymer was chosen to produce a water temperature indicator, which changes colour from blue to white when temperature increases; a CCU RED filament of photo-responsive polymer was used to produce a sunlight / UV indicator bracelet; a transparent PLA CLEAR polymer, a CCU RED photo-responsive polymer, and an electrical conductive PLA polymer were selected to produce a smart business card stand. The temperature indicator capability was analysed based on examining colour changes as a function of temperature changes. The sunlight/UV indicator capability was analysed based on the inspection of colour change as a function of absorbed sun/ultraviolet light. The electrical conductivity of the conductive PLA polymer was examined by performing resistance measurements. All three objects were successfully produced and their functionality was demonstrated. We hope that these examples will catalyse the expansion of FFF 4D printed SRP applications, as much work remains to be done in designing the parts and developing FFF printing parameters that take advantage of the stimuli-responsive materials currently being developed for FFF technology.
AM-FFF of Objects Using Commercial PLA Based Shape Memory Polymer Printed by an Open-Source 3D Printer
Authors: Dresler N. , Ulanov A. , Aviv M. , Ashkenazi D. , Stern A.
Published: January 2021

The 4D additive manufacturing processes are considered today as the "next big thing" in R&D. The aim of this research is to provide two examples of commercial PLA based shape memory polymer (SMP) objects printed on an open-source 3D printer in order to proof the feasibility of such novel 4D printing process. To that purpose, a PLA based filament of eSUN (4D filament e4D-1white, SMP) was chosen, and two applications, a spring and a vase, were designed by 3D-printing with additive manufacturing (AM) fused filament fabrication (FFF) technique. The 4D-printed objects were successfully produced, the shape memory effect and their functionality were demonstrated by achieving the shape-memory cycle of programming, storage and recovery.
Elaboration and Characterization of the Nanometric Titanium Diboride Powders by Mechanical Milling Method
Authors: Stefan I. , Benga G. C.
Published: January 2021

The research activities are oriented towards elaborating and characterizing nano-sized powders by powder metallurgy technologies based on wet milling in a planetary mill. For the elaboration of the TiB2 powders, a wet milling regime of initial powders was used up to nano size with the following parameters: milling technology by collision, milling times, rotational speed. The characterization of the TiB2 material will include particle size distribution analysis. EDXS and SEM analysis were used to study the structural evolution of the powder after ball milling. The mechanical milling technology, by its milling regimes, proved to be very efficient, obtaining a reduction of the titanium diboride powders particle size up to 50% compared to the initial unmilled powders.
Metal Alloys for Filaments in 3D Fusion Filament Modelling Printing Process
Authors: Ciornei M. , Savu I. D. , Savu S. V.
Published: January 2021

The paper presents experimental research regarding the application of specific low melting metals in the FDM process. Previous trends in the transfer of the filament from the spool to the hot-end showed that the filament undergoes specific mechanical stress during the transfer. To achieve an appropriate transfer the filament should prove stiffness and resistance to the mechanical actions of the transfer wheels. At the same time, the entrance to the hot-end creates specific resistance to the movement of the filament, and the filament undergoes important deformations. The experimental research used three materials characterized by melting temperature below 260oC: Sn-58Bi, Sn-9Zn, and Sn-3.5Ag. Sn-58Bi showed a yield stress above 50 MPa, but very low extension during the tensile test. Sn-9Zn exhibited a yield stress above 30 MPa, and about double the extension during the tensile test. Sn-3.5Ag displayed a yield stress above 25 MPa, and extension in excess of 8%. The analysis of the surface was performed, revealing that the increase of the yield stress influenced the appearance of specific prints given by the transfer wheels. The deepest prints were measured for Sn-3.5Ag and they were maximum 100 μm. The other two materials were stiffer and the prints have depths below 50 μm. According to the obtained results, each of the tested materials can be an appropriate solution to filament use for the FDM 3D printing process.
Mechanical Properties, Structure and Fracture Behavior of Additive Manufactured FFF-ABS Specimens
Authors: Gewelber O. , Rosenthal Y. , Ashkenazi D. , Stern A.
Published: January 2021

The Fused Filament Fabrication (FFF) method is one of the most important additive manufacturing (AM) technologies. This technology is used today with various kinds of thermoplastic materials, including ABS. The present study deals with the flexural strength and axial deflection of ABS specimens versus relative density, to observe the influence of build-orientations, build model and microscopic level defects of these properties. In this study, the mechanical and structural characterization of AM-FFF ABS material was studied by CAD modelling of different orientations, three point bending mechanical testing, visual testing, and multifocal light microscopy observation, including fractography analysis. To that end, three different standard building orientations (Flat, On Edge and Upright) were printed, and each was built in two different angle orientations (-45o/+45o and 0°/90o). Based on the three point bending testing results, it was found that the specimen with the highest flexural strength was not necessarily the one with the highest deflection. It was also observed that On Edge 0/+90o orientations showed a relatively larger flexural strength difference in comparison to other building orientations (Flat and Upright). When the mechanical properties achieved from a bending test next to the building platform were compared to the properties far from the building platform, only a slight difference was found, which means that the flexural strength difference results from the building strategy and it is not related to the specific bending surface. Based on fractography observation, there is a major difference in the mechanical properties and fracture surface appearance, when the samples are bent between the layers (Upright orientation) or when the samples are bent through the layers (Flat and On Edge orientation).
Sustainability of the Pension System, Risks and Opportunities
Authors: Péter Ákos , Németh Erzsébet , Vargha Bálint Tamás
Published: January 2021

All other things being equal by 2060 out of 10 of the working age population 6 pensioners will be accounted for. This does constitute a risk for the sustainability of pensions. Our study has analysed the most recent data on demographics, economy, employment, and its underlying factors, as well as the expected development of the figures of the pension fund. Our findings point to that the shrinking of the population of women of childbearing age will result in a constant decrease of birth rates even by a modest increase in fertility rates. Therefore, family policy measures - being indispensable - are of their own insufficient to mitigate the economic and pension risks. Due to its conjunctural nature economic growth can only temporarily mitigate the risks. On the other hand, the extension of the labour market activity of elderly people can set back the increase in pension costs with well predictable efficiency. Means to this end can include promoting activity at old ages, raising retirement ages, preserving physical and mental well-being and employability, as well as spreading the culture of self-reliance.
Metamorfose de uma melodia
Authors: Peretz I. L.
Published: January 2021

Metamorfose de uma melodia
música e a invenção do desejo
Authors: Nascimento Lyslei
Published: January 2021

Resenha a: AVIGUR-ROTEM, Gabriela. Mozart não era judeu. Trad. Nancy Rosenchan Rio de Janeiro: Imago, 1997. 388p
SIW Horn Antenna with a Special Coplanar Transition and Dielectric Lens for Feeding a Leaky-Wave Antenna
Authors: Ostankov A. V. , Khripunov E. G.
Published: January 2021

The paper describes the main phases and features in designing a feeder for a leaky-wave antenna in the Ka-band. The problem of feeding can be effectively solved using a horn antenna SIW technology-based and single substrate-integrated with the radiating aperture of the leaky-wave antenna. Unlike most similar studies, where an aperture exciting from a closed-type structure is analyzed, in our work the open-type antenna feeder is synthesized.

In the paper, we give a brief overview of the main achievements in designing traditional SIW-structures and present relations for their calculation. Basing on results of electromagnetic modeling, determine the influence of the substrate permittivity on the efficiency of SIW transmission line by the method of finite Weiland integrals. Consider the most popular types of the waveguide transitions to SIW, including micro-strip lines and grounded coplanar waveguides (GCPW). Depending on the required bandwidth and substrate dimensions specify conditions for selecting a design type of the waveguide transition.

A special attention is paid to the non-standard coplanar transition with an elevated grounded surface (EGCPW), which is worth using if the substrates are thick. It was used as a basis for designing a new, more efficient EGCPW transition with the elevated grounded surface, which contains specially made slots (SEGCPW). Recommendations for its adjustment are given.

The dependences of the gain on the aperture width for the H-plane SIW horn antenna, which are used to select its optimal size, are obtained basing on simulation. It was found that for matching the feeder with the leaky-wave antenna and decreasing the side lobes level, a dielectric lens with through holes worth using. Basing on the simulation of the unit cell of the lens the dependence of the effective permittivity on the diameter of the through hole is obtained. An influence of the non-uniformity degree of the lens with the holes of different diameters on the radiation efficiency of a horn antenna is determined. The complete design of the synthesized feeder and its radiation pattern is presented to prove the antenna efficiency in the wide frequency band.
Optimizing Strap-down Inertial Navigation Systems Characteristics and External Correction Sensors for Autonomous Navigation of Different UAV Classes
Authors: Starovoytov E. I.
Published: January 2021

Currently, unmanned aerial vehicles (UAVs) can be used in topographic works, condition monitoring and diagnostics of extended engineering structures, delivering goods to hard-to-reach places, etc. To provide the widespread UAVs applications and raise the number of tasks to be solved through their using, it is necessary to increase their autonomy degree in terms of navigation support, in particular. Unmanned aerial vehicles (UAV) control systems for autonomous navigation use the strap-down inertial navigation systems (SINS) based on various types of gyroscopes. SINS based on the laser gyroscopes, which have a large mass, have the best accuracy. UAVs with a payload mass that is commensurable with the mass of navigation equipment require optimization of SINS characteristics.

 An optimization method has been developed to enable obtaining a Pareto set for the mass and accuracy of SINS based on laser gyroscopes. A comprehensive assessment of the characteristics of SINS and UAV carrier with different payload mass has been performed. Various SINS correction methods are considered when satellite navigation is unavailable.

For overland flights, the correlation-extreme navigation systems (CENS) and SLAM methods (for simultaneous localisation and mapping) can be used. CENS require a reference lay-of-the-land description and a sufficient density of landmarks. In navigation based on SLAM algorithms, there is no need in the reference lay-of-the-land description, and the initial data can be obtained through the optical sensors under appropriate condition of the atmospheric path.

Regardless of the condition of the atmospheric path, type of the underlying surface and its information available in detail, the UAV coordinates can be determined by Doppler dead reckoning using a Doppler system (DISS). At low and medium altitudes SINS correction is possible, only heading sensor data are needed to calculate the path angle.

In combining with DISS and 3D Flash Ladar sensors (for implementing SLAM algorithms), it is more optimal to use low-accuracy SINS based on fibre-optic gyroscopes rather than laser gyro-based systems.

The results obtained can be used when developing navigation systems for medium, light and heavy-medium UAVs.
Impact Analysis of the Atmosphere Optical State on Wind Lidar Sounding Range
Authors: Belov M. L. , Samsonova A. A. , Ivanov S. E. , Gorodnichev V. A.
Published: January 2021

One of the most important questions for correlation lidars is the sounding range question.

Correlation lidar sounding range greatly depends not only on the parameters of the equipment, but also on the optical state of the earth's atmosphere.

In addition, there are currently two approaches to the estimation of lidar sounding range. In one approach, an estimate of the sounding range is obtained by equating the detector threshold power to the laser signal power recorded by the detector. In another approach, an estimate of the sounding range is obtained by equating the minimum detectable energy of the detected laser signal energy.

This paper is about impact research of the atmosphere optical state on wind correlation lidar sounding range and compare sounding range estimates obtained under the two different approaches to the energy calculation lidar.

The analysis is carried out for the surface layer of the atmosphere, the horizontal sounding path and the radiation wavelength of 0.532 μm. In atmospheric haze conditions, an empirical formula is used for the attenuation factor. The signal-to-noise ratio is assumed to be 100.

Solid-state Nd:YAG Ekspla lasers NL319 (lamp pumping, pulse energy 5 J) and NL231-100 (diode pumping, pulse energy 90 mJ) were chosen as radiation sources.

Hamamatsu photomultiplier tube R5070A with radiant sensitivity ~ 50 mA/W was chosen as a detector.

It is shown that in a wide optical state range (meteorological range of visibility from 20 to 2 km) the lamp-pumped laser source sounding range with pulse energy 5 J varies from ~ 3,8 km to ~ 1,2 km and the diode-pumped laser source sounding range with pulse energy 90 mJ varies from ~ 1,1 km to ~ 0,64 km.

The approach based on comparison of the detector threshold power with the received laser signal power overestimates the sounding range due to incomplete influencing consideration factors.
RESPON SAWI (Brassica juncea L) TERHADAP POC AIR LIMBAH BUDIDAYA LELE PLUS (ALBL PLUS)
Authors: Firman Firman , Aryani Farida
Published: January 2021

Produksi sayuran termasuk Sawi (Brassica juncea L) organik masyarakat kita perlu ditingkatkan  diantaranya melalui pemberian pupuk organik cair.  Pupuk Organik Cair Air Limbah Budidaya Lele kaya nitrogen (POC ALBL-PLUS) merupakan pupuk organik cair kaya  hara nitrogen, sehingga sangat berpotensi untuk diberikan pada tanaman sayuran khususnya sawi.  Penelitian respon sawi (Brassica juncea) terhadap pupuk organik cair air limbah budidaya lele kaya nitrogen (POC ALBL-PLUS) perlu dilakukan untuk memperoleh rekomendasi aplikasi POC ALBL-PLUS yang terbaik pada tanaman sawi.  Penelitian menggunakan Rancangan Acak Lengkap Faktor Tunggal dengan 6 ulangan.  Aplikasi POC ALBL-PLUS sebagai perlakuan adalah; A =  0,0 g/l (kontrol), B =   5 g/l  tiap 5 hari sekali,  C =   5 g/l tiap 10  hari sekali, D = 10 g/l tiap 5 hari sekali, E =   10 g/l tiap 10 hari sekali, F =   15 g/l tiap 5 hari sekali, G =  15 g/l tiap 10 hari sekali, H = 20 g/l tiap 5 hari sekali, I = 20 g/l tiap 10 hari sekali.  Aplikasi POC ALBL-PLUS tidak berpengaruh nyata terhadap tinggi tanaman dan umur berbunga, berpengaruh nyata terhadap jumlah daun serta berpengaruh sangat  nyata terhadap berat berangkasan basah tanaman caesim (Brassica juncea L). Aplikasi POC ALBL_PLUS 5 g/l dengan waktu pemberian tiap lima hari sekali (perlakuan B) meningkatkan jumlah daun dua kali lebih banyak dan berat berangkasan basah  enam kali lebih berat dibandingkan tanpa aplikasi POC ALBL-PLUS (kontrol).Kata Kunci :  POC, Nitrogen, Sawi
Pengaruh Lama Perendaman Dan Konsentrasi Kalium Nitrat (KNO3) Terhadap Pematahan Masa Dormansi Biji Kopi Robusta (Coffea canephora)
Authors: Wijaya Alam , Fitriani Dwi , Hayati Rita
Published: January 2021

Pembibitan kopi sering dihadapkan dengan masa dormansi biji kopi yang disebabkan oleh kulit ari biji kopi yang keras. Kalium nitrat (KNO3) dapat melunakkan kulit biji dan mempermudah air masuk ke dalam biji, sehingga mempercepat proses metabolisme. Penelitian ini bertujuan untuk mengetahui pengaruh lama perendaman dan konsentrasi kalium nitrat (KNO3) terhadap pematahan masa dormansi biji kopi robusta. Rancangan penelitian ini menggunakan Rancangan Acak Lengkap Faktorial (RAL-F), dengan faktor pertama lama perendaman (L) yang terdiri atas tiga taraf meliputi 12 jam (L1), 24 jam (L2), 36 jam (L3) dan faktor kedua konsentrasi KNO3 (K) yang terdiri atas 4 taraf meliputi 0% (K0), 0.5% (K1), 1.0% (K2) dan 1.5% (K3). Faktor lama perendaman berpengaruh nyata terhadap kecambah normal (biji), kecambah abnormal (biji), daya berkecambah (%), potensi tumbuh maksimum (%), waktu berkecambah (hr). Faktor konsentrasi KNO3 berpengaruh nyata terhadap kecambah normal (biji), kecambah abnormal (biji), daya berkecambah (%), potensi tumbuh maksimum (%) dan waktu berkecambah (hr). Hasil penelitian ini menunjukkan bahwa terdapat interaksi antara lama perendaman (L) dan konsentrasi kalium nitrat (K) terhadap efektivitas pematahan masa dormansi biji kopi robusta.Kata kunci : dormansi, lama perendaman, konsentrasi, kalium nitrat, robusta.