bluuebunny/crossref_metadata_2025 huggingface dataset:
Entre el bosque y los árboles
Authors: Gould Jeffrey
Published: March 2021

Este libro presenta casos de experimentos sociales en El Salvador, Nicaragua, y Uruguay. En estos espacios, donde florecía la comunicación horizontal y multi-clasista, el concepto de utopías menores de Jay Winter es apropiado. Este ensayo toma inspiración de esa obra importante de Winter, rastreando lo que él llama las »visiones de transformación parcial«, que coexistían temporalmente con las grandes narrativas de transformación social, pero después perdieron su lugar propio en el record histórico. Trabajadores agrícolas en Chinandega, minifundistas en Morazán, y obreros fabriles en Montevideo, en medio de graves crisis sociales-económicas y políticas conquistaron espacios para defenderse, pero también de crear nuevas relaciones sociales y una experiencia de trabajo colectiva y libertadora.
La crisis de los regímenes progresistas y el legado del socialismo de Estado
Authors: Meschkat Klaus
Published: March 2021

Los regímenes progresistas se encuentran en una profunda crisis. Quien no se contenta con denunciar las previsibles maquinaciones del »imperialismo«, debe buscar las razones internas del fracaso del proclamado »socialismo del siglo XXI«. ¿Por qué tales regímenes, que deben su aparición y sus éxitos iniciales en gran medida a la movilización de las masas, no han podido mantener el apoyo activo de una mayoría de la población? La respuesta se busca aquí recurriendo al historial de la izquierda latinoamericana. El objetivo es mostrar cómo el concepto organizativo de Lenin ha llegado a América Latina, comenzando con las intervenciones de la Internacional Comunista. Se examina si este legado también ha influido en los protagonistas del »progresismo« y de qué manera. La reflexión en la parte principal se basa en el papel central de Hugo Chávez y su relación ambivalente con la herencia histórica de la izquierda.
Retrieval of Separated NiTi Instrument in Severe Curved Canal using an Ultrasonic Device: A Case Report using an Ultrasonic Device: A Case Report
Authors:   Department of Conservative Dentistry, Faculty of Dentistry, Universitas Indonesia, W. Putranto Aditya , D. Maharti Ike ,   Department of Conservative Dentistry, Faculty of Dentistry, Universitas Indonesia, Megantoro Aryo ,   Department of Conservative Dentistry, Faculty of Dentistry, Universitas Indonesia, Ricardo Shalina ,   Department of Conservative Dentistry, Faculty of Dentistry, Universitas Indonesia
Published: March 2021

Objective: We describe how to assess the degree of canal curvature and manage a separated instrument using an ultrasonic device. Case Report: A 24-year-old female was referred by a general dentist for an accidentally separated Protaper F2 instrument. The mesiobuccal canal was enlarged and the separated instrument could be visualized via the dental operating microscope. Preoperative radiography revealed a separated endodontic instrument at the middle to apical third of the mesiobuccal canal. Mesiobuccal canal curvature measured 66°. After rubber dam isolation, a specific ultrasonic tip and the dental operating microscope were used to gain access around the separated instrument until it loosened. The separated instrument was agitated and accidentally sucked into the high-speed suction device. The canal was evaluated with higher magnification via the dental operating microscope and postoperative radiographs were taken to confirm removal. Conclusion: Retrieval of a separated instrument in the curved canal is effective using a specific ultrasonic device plus a dental operating microscope
Revisiting a Funding Model for University-led Dental Clinics: The Case of Complete Denture Fabrication Case of Complete Denture Fabrication
Authors:   Department of Prosthodontics, Faculty of Dentistry, University Teknologi MARA, 47000 Sungai Buloh, Malaysia, Ahmad Rohana ,   Integrative Pharmacogenomics Institute, 42300 Puncak Alam, Selangor, Malaysia, Amalina Zul Nur ,   Department of Prosthodontics, Faculty of Dentistry, University Teknologi MARA, 47000 Sungai Buloh, Malaysia, Anisah Mohtar Siti ,   Department of Prosthodontics, Faculty of Dentistry, University Teknologi MARA, 47000 Sungai Buloh, Malaysia, Tennant Marc ,   Faculty of Science, School of Human Science, University of Western Australia, 6009 Perth, Australia, Ningseh Mohd-Dom Tuti ,   Department of Family Oral Health, Faculty of Dentistry, Universiti Kebangsaan Malaysia, 50300 Kuala Lumpur, Malaysia
Published: March 2021

Objectives: University-led dental clinics are rarely seen as core to the national healthcare system. Thus, when publicly funded universities experience a decline in government support, dental clinic services operated by students are confronted by a potentially inadequate operating budget. Prompted by the need for strategic resource allocation, this study seeks to quantify the resources consumed in the construction of complete dentures by undergraduate students in an effort to identify opportunities for cost-cutting measures. Methods: Clinical cases were retrieved from the logbooks of graduating students of Class 2015, and patient records were reviewed to identify and quantify all clinical and laboratory procedures involved in constructing a set of complete dentures. Cost estimation was carried out using the activity-based method on the basis of direct medical costs. Results: A total of 83 patient records were reviewed. The average number of visits required to fabricate a set of complete dentures was 10 (range, 6–20 visits) with an average total cost of MYR2131±538 (€450±114). The number of visits contributed substantially to the total cost, and procedures requiring multiple visits included secondary impression and jaw relation recording. The major cost components were dental equipment (44%), laboratory costs (28%), dental consumables (17%), salaries (7%), and dental instruments (3%). Conclusion: The operating cost for training students in denture fabrication is substantial. Schools should formulate strategies to reduce the number of patient visits by ensuring that students optimize the time spent per visit. A financially sustainable model to fund dental training is necessary to ensure that quality of care is not compromised in university-led clinics.
Conservative Management of a Maxillary Lateral Incisor with an Apical Third Root Perforation: A Case Report Apical Third Root Perforation: A Case Report
Authors:   Conservative Dentistry Residency Program, Faculty of Dentistry, Universitas Gadjah Mada, Yogyakarta, Indonesia, Astrina Damayanti Nurul , Natalina Fuddjiantari Dian ,   Conservative Dentistry Residency Program, Faculty of Dentistry, Universitas Gadjah Mada, Yogyakarta, Indonesia, Endra Untara Tri ,   Department of Conservative Dentistry, Faculty of Dentistry, Universitas Gadjah Mada, Yogyakarta, Indonesia, Kristanti Yulita ,   Department of Conservative Dentistry, Faculty of Dentistry, Universitas Gadjah Mada, Yogyakarta, Indonesia
Published: March 2021

Perforation is one of iatrogenic factors responsible for endodontic failure. Root canal perforation can occur at the cervical, mid-root, or apical levels. Non-surgical (conservative) perforation repair offers less tissue destruction and easy isolation during treatment. Objective: To explain the management of apical third root perforation using the conservative technique. Case Report: This case report describes a 29-year-old patient who came for management of right maxillary lateral incisor with apical third root perforation on the labial aspect. The location of apical third root perforation was evaluated using cone beam computed tomography (CBCT). Root perforation was sealed using mineral trioxide aggregate (MTA). MTA was applied in conservative technique with hand filling. MTA was dispensed into the original canal while maintaining the patency of the perforated canal, followed by dispensed of MTA into the perforated canal. Conclusion: Root perforation should be identified as soon as possible and could be easily examined using CBCT. Non-surgical root perforation treatment is recommended in intact periodontal attachment and in absence of inherent complication. Repairing the root perforation promote the proper healing of the periapical tissue and increase the success rate of retreatment.
Effect of Craniofacial Growth Pattern on Head Posture
Authors:   Department of Orthodontics, Faculty of Dentistry, Antalya Bilim University, Antalya, Turkey, Kale Burak , Hilmi Buyukcavus Muhammed ,   Department of Orthodontics, Faculty of Dentistry, Suleyman Demirel University, Isparta, Turkey
Published: March 2021

Head posture refers to the upright position of the head of a standing or sitting subject. The literature reports that head posture is affected by many factors. Objective: To evaluate differences in head posture according to craniofacial growth pattern. Methods: A total of 163 individuals (83 females and 80 males) were included in this study. Patients were divided into three groups according to ANB angle as Class I, Class II, and Class III, and each group was divided further into three subgroups according to SN/GoGn angle as hyperdivergent, normodivergent, and hypodivergent. The patients were compared in terms of head posture measurements. Two-way ANOVA was used to evaluate the main and interactive effects of vertical growth pattern and malocclusion type on the head posture of the patients. Results were considered statistically significant at p < 0.05. Results: No statistically significant difference between malocclusion and face-type groups was observed in all head posture measurements (p > 0.05). Conclusion: Head posture is similar among subgroups of different malocclusion types separated by vertical growth pattern.
Comparison of Popular Three-Dimensional Printing Materials for Oral and Maxillofacial Surgical Guidance Model Oral and Maxillofacial Surgical Guidance Model
Authors:   Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Universitas Indonesia, Jakarta, Indonesia, Adhitya Mohammad , Sunarso Sunarso ,   Department of Dental Material Science, Faculty of Dentistry, Universitas Indonesia, Jakarta, Indonesia, Muis Abdul ,   Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Jakarta, Indonesia
Published: March 2021

The application of three-dimensional (3D) models in the medical field has become popular. However, the accuracy of 3D models for surgical guidance varies among different materials and 3D printing technologies, such as printing machine usage. Objectives: This study aims to obtain more information about the effect of three different materials printed using a fused deposition material printer from the same digital data source. This study also aims to compare, analyze, and test the materials’ ability. Methods: Each of the filament materials (acetylbutane stearate [ABS], polylactic acid [PLA], and high-impact polystyrene [HIPS]) are printed at two infill densities, their weight, volume, and dimension are measured, and infill materials are prepared. Printing time is estimated and calculated on the basis of printing properties by using Simplify3D© software. The strength and surface tension of each sample are examined via a drilling test. Results: PLA is better than ABS and HIPS for printing our 3D model because of its properties. Conclusion: Ideal 3D materials for printing 3D models should fulfill the criteria on accuracy, strength, weight, and durability for usage. However, production time and cost should also be considered.
Forest certification in developing countries: current status and hindrances to its adoption within a macro-framework
Authors: Xu L. , Lu A.J.
Published: March 2021

Forest certification has been widely hailed for its positive impacts on implementing sustainable forest management. Despite various adjustments to promote its adoption, most of the world's certified forests are in developed countries, with about 87% in Europe and North America. To analyse
the reasons for the slow certification uptake in the developing world, two rounds of literature searches were conducted, and the hindrances identified were then discussed under six themes: forest quality, socioeconomic interactions, governance capacity, certification investment, firm expectations
and market responses, and risk aversion and the attitude-behaviour gap. Among them, conventional institutions and governance are the most restrictive constraints. Certification, while a non-state form of governance, may not exercise its regulatory power freely through the market without being
impeded by the unfavourable contexts in which it takes hold. Finally, recommendations were proposed from the perspectives of politics, legislation, market, and certification schemes to resolve the hindrances in achieving certification.
Retrofitting recycled stripping gas in a glycol dehydration regeneration unit
Authors: Kurniawan Adhi , Handogo Renanto , Purwo Sutikno Juwari
Published: March 2021

Natural gas dehydration is essential in gas processing to avoid serious problems. As a pretreatment in a cryogenic Natural Gas Liquid (NGL) recovery process, it typically uses triethylene glycol (TEG) and followed by a Molecular Sieve dehydration to achieve 1 mg/Sm3 of water moisture in the dehydrated gas. This work studied the retrofitting of the existing dehydration unit to improve its performance in satisfying the gas moisture qualities. The retrofitted process uses recycled stripping gas schemes to achieve high purity TEG while minimizing the use of fresh stripping gas. The results revealed that the recycled stripping gas has provided sufficiently high purity TEG (>99.99%-wt), significantly reduced the heating and cooling duty by 80%, and reduced the electrical duty by 29% compared to the base case. The TAC was reduced by 38.1% from $ 725,245/year to $ 448,670/year. Through this study, the evaluated cases provide similar dehydration results with less equipment, simpler process, more energy-efficient, and better economic numbers. Therefore, a better process was obtained.
The complexity and history of verb-stem ablauting patterns in Siyuewu Khroskyabs
Authors: Lai Yunfan
Published: March 2021

This paper describes the ablauting patterns in Siyuewu Khroskyabs, an understudied Gyalrongic language. Ablaut is only found in verbs containing closed syllables, and ablaut patterns in Siyuewu preserve Proto-Khroskyabs patterns relatively well. After providing a synchronic description of verb-stem functions and ablauting patterns, implicative entropy is used to model Siyuewu’s ablauting status. Entropy measurements reveal Siyuewu to have relatively low ablaut predictability, which may be suggestive of a historically conservative ablauting system. On the basis of this quantitative analysis, the current paper proposes an internal reconstruction of ablauting patterns, and postulates a series of velarised vowels for Proto-Siyuewu. Analogical changes are identified through comparison with other Gyalrongic languages. The reconstructed verb forms and patterns are then compared with neighbouring Gyalrongic languages and the directionality of analogy is discussed.
Alternations of classificatory verb stems in Tłı̨chǫ Yatıì: a cognitive semantic account
Authors: Al-Bataineh Hussein
Published: March 2021

This paper investigates the phenomenon of ‘classificatory verbs’, i.e. a set of motion and positional verbs that show stem alternations depending on the semantic features of one of their arguments in Tłı̨chǫ Yatıì (Dogrib), based on field notes and documentary sources of the language. The paper shows that Tłı̨chǫ classificatory verbal categories belong to four semantic subclasses which have inconsistent stem inventories caused by the presence or absence of some semantic features. Stem inventories of locative verb systems vary depending on the scalar [effort] feature, and those of motion verbs correlate with the scalar [agentive] feature. The paper explains why other semantically related verbs do not show stem alternations and proposes contrastive hierarchies to represent variations in stem inventories intra- and cross-linguistically assuming that the selection of a stem for a particular semantic category follows a series of binary choices that characterize the opposition’s active in the language.
Analog signal processing through space-time digital metasurfaces
Authors: Rajabalipanah Hamid , Abdolali Ali , Iqbal Shahid , Zhang Lei , Cui Tie Jun
Published: March 2021

In the quest to realize analog signal processing using subwavelength metasurfaces, in this paper, we present the first demonstration of programmable time-modulated metasurface processors based on the key properties of spatial Fourier transformation. Exploiting space-time coding strategy enables local, independent, and real-time engineering of not only amplitude but also phase profile of the contributing reflective digital meta-atoms at both central and harmonic frequencies. Several illustrative examples are demonstrated to show that the proposed multifunctional calculus metasurface is capable of implementing a large class of useful mathematical operators, including 1st- and 2nd-order spatial differentiation, 1st-order spatial integration, and integro-differential equation solving accompanied by frequency conversions. Unlike the recent proposals based on the Green’s function (GF) method, the designed time-modulated signal processor effectively operates for input signals containing wide spatial frequency bandwidths with an acceptable gain level. Proof-of-principle simulations are also reported to demonstrate the successful realization of image processing functions like edge detection. This time-varying wave-based computing system can set the direction for future developments of programmable metasurfaces with highly promising applications in ultrafast equation solving, real-time and continuous signal processing, and imaging.
Metallographic Preparation of Single Powder Particles
Authors: Milkereit B. , Meißner Y. , Ladewig C. , Osten J. , Peng Q. , Yang B. , Springer A. , Keßler O.
Published: March 2021

This work developed a systematic method for a metallographic preparation of single powder particles with diameters of approx. 20 to 40 μm. It was motivated by the objective of understanding additive manufacturing processes such as Laser Powder Bed Fusion. A fundamental aspect of the relationship between manufacturing, structure, and properties is the correlation of rapid solidification and resulting microstructure. During powder-based additive manufacturing processes, cooling rates up to 1 MK/s are attained. A thermal analysis determining the characteristics of solidification at such rapid cooling rates can be performed with the aid of chip sensor-based, dynamic Differential Fast Scanning Calorimetry, DFSC. For this purpose, the heat flow during the solidification of single powder particles is measured and, for instance, the solidification onset temperature is evaluated as a function of cooling rate. It is thus possible to estimate the undercooling which has a significant impact on the resulting structure. Subsequently, cross sections of single powder particles must be prepared for the analysis of the resulting structure.
Biochar caged zirconium ferrite nanocomposites for the adsorptive removal of Reactive Blue 19 dye in a batch and column reactors and conditions optimizaton
Authors: Perveen Shazia , Nadeem Raziya , Ali Shaukat , Jamil Yasir
Published: March 2021

Biochar caged zirconium ferrite (BC-ZrFe2O5) nanocomposites were fabricated and their adsorption capacity for Reactive Blue 19 (RB19) dye was evaluated in a fixed-bed column and batch sorption mode. The adsorption of dye onto BC-ZrFe2O5 NCs followed pseudo-second-order kinetics (R
2 = 0.998) and among isotherms, the experimental data was best fitted to Sips model as compared to Freundlich and Langmuir isotherms models. The influence of flow-rate (3–5 mL min−1), inlet RB19 dye concentration (20–100 mg L−1) and quantity of BC-ZrFe2O5 NCs (0.5–1.5 g) on fixed-bed sorption was elucidated by Box-Behnken experimental design. The saturation times (C

t
/C

o
 = 0.95) and breakthrough (C

t
/C

o
 = 0.05) were higher at lower flow-rates and higher dose of BC-ZrFe2O5 NCs. The saturation times decreased, but breakthrough was increased with the initial RB19 dye concentration. The treated volume was higher at low sorbent dose and influent concentration. Fractional bed utilization (FBU) increased with RB19 dye concentration and flow rates at low dose of BC-ZrFe2O5 NCs. Yan model was fitted best to breakthrough curves data as compared to Bohart-Adams and Thomas models. Results revealed that BC-ZrFe2O5 nanocomposite has promising adsorption efficiency and could be used for the adsorption of dyes from textile effluents.
Autonomisierung von Shopfloor Management
Authors: Bock Tobias , Höfer Stephan
Published: March 2021

Neue Technologien der Digitalisierung, Vernetzung und künstlichen Intelligenz werden zunehmend auch im Shopfloor Management (SFM) Einzug halten. Dieser Beitrag beschreibt in vier Stufen, wie sich das klassische SFM über das digitale SFM hin zu einem smarten und autonomen SFM entwickeln könnte. Darauf aufbauend wird diskutiert, welche Auswirkungen der Einsatz dieser neuen Technologien auf die operative Gestaltung der Durchführung eines SFM hätte und welche Konsequenzen somit auf Mitarbeiter und Führungskräfte zukommen würden.*)
Anwendungen aktiver Traceability-Systeme
Authors: Urnauer Christian , Schreiber Markus , Bausch Phillip , Metternich Joachim
Published: March 2021

Mithilfe aktiver Traceability wird durch die Verknüpfung von Maschinen-, Prozess- und Produktdaten die Transparenz über Produktionsprozesse gesteigert. Anhand der Umsetzungen im Transferprojekt ArePron wird in diesem Beitrag beispielhaft aufgezeigt, welche konkreten Industrieanwendungen sich durch die Nutzung dieser Traceability-Daten realisieren lassen. Dabei werden Anwendungen aus den Bereichen Kundendienstleistung, Echtzeitabbild von Leistungskennzahlen, Dynamische Prozesssteuerung, Prozessanalyse sowie Lagermanagement betrachtet.**)
Digitales Bauzustandsmonitoring im Schiffbau
Authors: Sender Jan , Geist Michael , Fischer Anne , Flügge Wilko
Published: March 2021

Schiffbauprojekte müssen trotz steigendem Arbeitsumfang in immer kürzeren Lieferzeiten fertiggestellt werden. Daher haben sich komplexe maritime Wertschöpfungsketten gebildet, die ein hohes Maß an Arbeitsteilung praktizieren. Während eines Schiffbauprojektes müssen viele Arbeiten und Akteure zeitlich und inhaltlich koordiniert werden. Die Kommunikation des Bauzustandes entlang der Wertschöpfungskette spielt eine entscheidende Rolle. Dieser Beitrag präsentiert einen Ansatz, wie durch geeignete Digitalisierung das Bauzustandsmonitoring im Schiffbau optimiert werden kann.
A Precarious Balancing Act
Authors: Lee Seungah S.
Published: March 2021

This paper explores the dynamics between globalization and local culture in analyzing how higher education (HE) has expanded in Qatar and the United Arab Emirates (UAE) through internationalization. It contends that HE expands through internationalization in part because these Arab Gulf states use higher education institutions (HEIs) to legitimate themselves and gain prominence as internationally competitive societies in a globalized world. At the same time, however, these Arab Gulf states face push back from their more conservative, traditional constituents who criticize the state for “Westernizing” education. Hence, these states simultaneously pursue anti-liberal practices in public HEIs to manage state–society relations, enabling them to maintain both national and global legitimacy. This effort to balance what appears to be two competing interests creates a “dual higher education system.”
Understanding the Rationales of Donor-Funded NGOs in Palestine
Authors: Suleiman Lina
Published: March 2021

This article uses game theory as a conceptual approach to gain a holistic understanding of the aid policy of donors supporting Palestinian nongovernmental organizations (PNGOs). It asks how the work of donor-funded PNGOs has impacted Palestinian societal common good in general, and who are the winners and losers as a result of their work. Quantitative methods are used to capture the perceptions of the main actors in relation to the societal outcomes of PNGOs’ work and actors’ political and socio-economic payoffs in the occupied West Bank. Most of the findings align with much of the critical research on the negative societal outcomes of the aid policy to the NGO sector, and corroborate that the Palestinian public is a major loser in political terms and the least beneficiary in socio-economic terms.
Changes in Internationalization at Home in Arab Higher Education Institutions
Authors: Zgheib Rosine , Loan Amira Van
Published: March 2021

As global marketplace competition increases, higher education institutions (HEIs) in the Arab world purposefully integrate international and intercultural dimensions into their curriculum, known as internationalization at home (IaH), to empower graduates with the tools necessary to strengthen their economies and be productive global citizens. The purpose of this research is to report changes in the internationalization strategies of fourteen randomly selected Arab world HEIs by looking at six IaH indicators in their mission statements, course descriptions, and strategic plans. The results prioritize internationalization in the HEIs’ mission statements with a twenty per cent increase in the number of indicators between academic years 2014–15 and 2019–20. Additionally, through course descriptions/titles, we found some universities were offering up to 350 courses promoted per indicator, with others offering as few as one course per indicator. We also found sixty-five per cent of the HEIs do not have explicit strategic plans, or rather no or implicit strategic plans incorporating internationalization. As the Arab world attempts to strengthen its economies, HEIs should continue to increase IaH efforts by infusing more of the indicators in their mission statements, courses, and strategic plans.
Pakistan’s Education Reform Test
Authors: Bari Faisal
Published: March 2021

The Pakistani Constitution promises “free and compulsory” education for all, but 20 million children are not in school. Many who are enrolled receive poor-quality education: surveys show Pakistani students ranking among the lowest achievers in the world. This has led families in all but the lowest income groups to seek private alternatives for their children, weakening the constituency for improved public schools. Under Prime Minister Imran Khan, the government has pushed for a Single National Curriculum. Critics contend that it will not address lack of access or the poor quality of education, but that it could lead to restrictions on school choice, provincial autonomy, and linguistic diversity, while imposing a narrow vision of national identity.
Modelling Drying Time of Candesartan Cilexetil Powder Using Computational Intelligence Technique
Authors: Keskes Sonia , Hentabli Mohamed , Laidi Maamar , Hanini Salah
Published: March 2021

The aim of this work was to use two computational intelligence techniques, namely, artificial neural network (ANN) and support vector regression (SVR), to model the drying time of a pharmaceutical powder Candesartan Cilexetil, which is used for arterial hypertension treatment and heart failure. The experimental data set used in this work has been collected from previously published paper of the drying kinetics of Candesartan Cilexetil using vacuum dryer and under different operating conditions. The comparison between the two models has been conducted using different statistical parameters namely root mean squared error (RMSE) and determination coefficient (R2). Results show that SVR model shows high accuracy in comparison with ANN model to predict the non-linear behaviour of the drying time using pertinent variables with {R2 = 0.9991, RMSE = 0.262} against {R2 = 0.998, RMSE = 0.339} for SVR and ANN, respectively.
Nitrogen Oxide Soil Emission Measurements Using Passive Samplers and Static Chamber Method
Authors: Zgorelec Željka , Pehnec Gordana , Mesić Milan , Kolman Mateja , Galić Marija
Published: March 2021

Nitrogen oxides play a major role in atmospheric chemistry, like primary pollutants, in the formation of secondary air pollutants or greenhouse gases (GHGs). This research study was conducted in the Western Pannonian sub-region of Croatia with the aim to determine the suitability of our internally developed passive sampler and static chamber method for N-NO2 concentration measurement. The aim was also to determine the impact of mineral soil fertilization on the N-NO2 flux during triticale vegetation. The research showed that the method used was suitable. Average daily N-NO2 flux ranged from 2.78 to 5.09 mg ha–1 day–1 depending on phenophase and treatment. Statistically significant differences in N-NO2 flux between two monitored treatments (300 kg N ha–1 and 0 kg N ha–1) were not observed, nor between two investigated phenophases.
Surgical Management of a Giant Left Sinus of Valsalva Aneurysm with Coronary Artery Abnormality
Authors: Song Long , Iroegbu Chukwuemeka Daniel , Fan Chengming , Zhou Xinmin
Published: March 2021

Coronary insufficiency caused by unruptured left sinus of Valsalva aneurysm (SVA) is exceedingly rare in the literature. Herein, we present a successful surgically treated case of giant left SVA with severe aortic regurgitation and coronary insufficiency, thus introducing a tailored valve-sparing aortic root repair technique.
The Median Sternotomy: The Unkindest Cut of All? Pearls, Pitfalls, Aphorisms, & Myths
Authors: Tribble Curt , Merrill Walter , Derryberry Stephen , Parrino Gene
Published: March 2021

While some have claimed that a median sternotomy is an ‘unkind cut,’ when this incision is performed, closed, and managed optimally, it can be one of the ‘most kind cuts’ used for major operations. The median sternotomy is the most commonly used incision for coronary artery bypass surgery, which is the most common operation performed in the United States at the current time. This approach is, of course, used for many other cardiac and thoracic operations, as well. It is, however, also one of the most misunderstood procedures in Surgery. Because it is an incision that even a novice surgical resident can perform, with proper supervision, the subtleties and nuances of not only opening but also of closing sternotomies are not often conveyed optimally to our trainees. In this treatise we will attempt to comprehensively address these subtleties, nuances, and misunderstandings, both for the benefit of our younger learners, but also, and more importantly, for the benefit of our patients.
The Concept of Pesticide-Free Pest Control in the Crimean Forests
Authors: Ivashov Anatoliy , Simchuk Andriy
Published: March 2021

Oak leafroller, gypsy and winter moths contribute to a pathological situation in the Crimean forests exposed to strong recreational activities, which add to the weakening of the forest ecosystems. In this respect we develop a concept of pesticide-free forest protection that presupposes an optimal balance between natural self-regulation opportunities and management, taking into account the long-term effects. The practical steps include preventive and current biological pest control, different in primary, secondary and tertiary niduses of pest outbreaks in the Crimean forests. All pest-control measures should be elaborated as a successive chain of steps joining in a common ecologically and economically sound system.  Preventive and current bio-control actions become easy and soft with increase in the forest’s ecosystem complexity and restoration of natural self-regulation.
Investigation and robust synthesis of polynomials under perturbations based on the root locus parameter distribution diagram
Authors:   United Institute of Informatics Problems of the Belarusian National Academy of Sciences, A.A. Nesenchuk
Published: March 2021

Investigation of the 4 th order dynamic systems characteristic polynomials behavior in conditions of the interval parametric uncertainties is carried out on the basis of root locus portraits. The roots behavior regularities and corresponding diagrams for the root locus parameter distribution along the asymptotic stability bound are specified for the root locus portraits of the systems. On this basis the stability conditions are derived, graphic-analytical method is worked out for calculating intervals of variation for the polynomial family parameters ensuring its robust stability. The discovered regularities of the system root locus portrait behavior allow to extract hurwitz sub-families from the non-hurwitz families of interval polynomials and to determine whether there exists at least one stable polynomial in the unstable polynomial family.
Computer model of control of a flat solar collector with a thermosifon circulation
Authors:   Institute of Information and Computational Technologies MES RK, M. Kalimoldaev , Y. Amirgaliyev ,   Institute of Information and Computational Technologies MES RK, M. Kunelbyaev ,   Institute of Information and Computational Technologies MES RK, T. Merembaev ,   Institute of Information and Computational Technologies MES RK, T. Sundetov ,   Institute of Information and Computational Technologies MES RK
Published: March 2021

This paper discusses the possibility of creating a digital platform based on Mojo v3 for monitoring the operation of a dual-circuit solar collector. In the proposed system, measurements are made from 6 digital sensors (DS18B20 Dallas), 16 wires are used. Using Dallas sensors and the appropriate software, you can monitor the temperature level and the amount of heat. The use of 6 digital sensors significantly increases the efficiency of control over the system and increases the speed of data processing. The possibilities of configuring sensors for the platform Mojo v3, as well as the control circuit of the solar collector are considered.
Ukrainian dactyl alphabet gesture recognition using convolutional neural networks with 3d convolutions
Authors:   Taras Shevchenko National University of Kyiv, S.S. Kondratiuk
Published: March 2021

The technology, which is implemented with cross platform tools, is proposed for modeling of gesture units of sign language, animation between states of gesture units with a combination of gestures (words). Implemented technology simulates sequence of gestures using virtual spatial hand model and performs recognition of dactyl items from camera input using trained on collected training dataset set convolutional neural network, based on the MobileNetv3 architecture, and with the optimal configuration of layers and network parameters. On the collected test dataset accuracy of over 98% is achieved.
Fuzzy Logic Control for a Soft Exoskeleton Glove Using a Motor-Tendon Actuator
Authors: Setiawan Joga Dharma , Ariyanto Mochammad , Nugroho Sri , Ismail Rifky , Purbayanto Tedi , Sihombing Haeryip
Published: March 2021

A hand is one of the essential limbs on the human body that is used for daily activities. The aim of this research is to develop a soft exoskeleton hand to assist people with hand deterioration. The developed exo-glove is made of low-cost RTV (room-temperaturevulcanizing) silicone rubber with a motor-tendon actuation system that produces the flexion and extension motion. Here, the actuator converts rotation motion into linear motion from DC motor, while a potentiometer sensor is utilized to measure therotation angle on the actuator system, in which fuzzy logic control (FLC) is employed for controlling the motion of the proposed motor-tendon actuator. To validate the function and mechanism of the developed soft exoskeleton glove, testing was conducted towards the FLC performance on the healthy human hand for various object grasping tests. Based on the test results, this studyshows that the soft glove can be implemented on the human hand as an assistive device.
Hazard Maps of Shallow Landslides Associated to Infiltration Processes in the Sapuyes River Basin
Authors: Rosales Cristhian
Published: March 2021

Hazard mapping of shallow landslides associated with infiltration processes at a regional scale was carried out by means of the spatial and temporal distribution of safety factor and its classification, within hazard level ranges, into cells that represent hillside units in Sapuyes river basin, located near the city of Pasto in the Nariño department. Hazard assessment follows the theoretical approaches of the Iverson model (2000), which takes into account the redistribution of underground pore pressures associated with the transient infiltration of the rain and its effects on the time and location of landslides, considering that shallow landslides are associated with periods of rain with a short duration and greater intensity. Results showed that both the pressure heads and the safety factor are valid approximations for hazard analysis at regional scale and allow observing the transient physical process involved in the development of shallow landslides.
De la virtualidad, las emociones y el trabajo sexual: un acercamiento desde el modelaje webcam.
Authors: Orduz Ramos Paula Daniela
Published: March 2021

Este artículo recoge uno de los planteamientos principales de un trabajo de investigación enfocado en el modelaje webcam, tomando como punto central del análisis la manera en la que las interacciones entre camgirls y clientes están moldeadas por la intersección entre tecnología y sociedad. El artículo se concentra en el trabajo emocional de las camgirls y describe las habilidades necesarias para el éxito en este oficio. Se argumenta que los lazos emocionales establecidos entre camgirl y clientes son centrales en las dinámicas sexuales dadas en la virtualidad, lo que genera una nueva perspectiva para los debates del trabajo sexual.
Vínculos, redes y relaciones virtuales en el proceso de agremiación estudiantil de Trabajo Social en Colombia
Authors: Alvarez Plazas Anderson Yamid , Bautista Joaqui Haider Esteban
Published: March 2021

El presente artículo analiza el proceso de agremiación estudiantil de Trabajo Social en Colombia desde las maneras de habitar los espacios virtuales, los vínculos creados entre sus integrantes y los tránsitos relacionales establecidos entre el ciberespacio y los entornos físicos. La metodología utilizada es cualitativa y las técnicas fueron entrevistas en línea y observación participante en redes sociales. Como resultados, se observa que las virtualidades fortalecen la identidad profesional, generan relaciones que trascienden lo académico y configuran mediaciones para la construcción de encuentros presenciales a nivel nacional. En conclusión, el mundo virtual y el físico son espacialidades conectadas, articuladas y relacionales.
Recurrent trichobezoar in a patient with Rapunzel syndrome
Authors:   Department of Paediatric Surgery, Jagiellonian University Medical College, University Children Hospital, Kraków, Poland, Godlewska Joanna , Orpiszewska Justyna ,   Department of Paediatric Surgery, Jagiellonian University Medical College, University Children Hospital, Kraków, Poland, Górecki Wojciech ,   Department of Paediatric Surgery, Jagiellonian University Medical College, University Children Hospital, Kraków, Poland
Published: March 2021

Rapunzel syndrome is a condition where a trichobezoar is formed in the stomach and proximal intestine due to hair ingestion. A 6-year-old girl presented to emergency department with abdominal pain, vomiting and a palpable epigastric mass. Laparotomy was performed for gastric foreign body; a trichobezoar that filled the stomach, duodenum and proximal small intestine was removed. Postoperative course was uncomplicated; the patient was discharged for further out-patient follow-up and psychological care. After 7 months, the girl presented with a recurrence. A recurrent trichobezoar was removed via laparotomy. The girl was started on psychiatric treatment and iron substitution for anaemia. Ten weeks after discharge, follow-up gastroscopy was negative for gastric foreign body. There are no guidelines for follow-up after trichobezoar removal. Since the disease may be recurrent, follow-up endoscopy should be considered in order to enable an early diagnosis and less invasive treatment.
Epiglottic abscess as a rare cause of muffled voice
Authors:   Department of Otorhinolaryngology – Head and Neck Surgery, School of Medical Sciences, Universiti Sains Malaysia Health Campus, Kota Bharu, Kelantan, Malaysia, Lamry Nur Adillah , Saifuddin Norhafizah ,   Department of Otorhinolaryngology – Head and Neck Surgery, Hospital Sultan Ismail, Johor Bahru, Malaysia, Mohamad Irfan ,   Department of Otorhinolaryngology – Head and Neck Surgery, School of Medical Sciences, Universiti Sains Malaysia Health Campus, Kota Bharu, Kelantan, Malaysia
Published: March 2021

A 42-year-old male presented with fever and symptoms of impending upper airway obstruction on the day of presentation. He required immediate intubation due to swollen epiglottis. The condition responded to antibiotic and steroids, and he was able to be extubated after 3 days. Two days later, however, the epiglottis started to swell up again, this time with pus discharge. Emergency exploration and drainage of the epiglottic abscess were executed, and the patient was kept intubated for a few days afterwards for the swollen epiglottis to reduce in size. Daily flexible laryngoscopy was commenced to monitor the disease status. After completing the antibiotic therapy the patient was discharged in good general condition.
Subthreshold membrane potential dynamics of posterior parietal cortical neurons coupled with hippocampal ripples
Authors: Sato Y. , Mizuno H. , Matsumoto N. , Ikegaya Y.
Published: March 2021

During behavioral states of immobility, sleep, and anesthesia, the hippocampus generates high-frequency oscillations called ripples. Ripples occur simultaneously with synchronous neuronal activity in the neocortex, known as slow waves, and contribute to memory consolidation. During these ripples, various neocortical regions exhibit modulations in spike rates and local field activity irrespective of whether they receive direct synaptic inputs from the hippocampus. However, little is known about the subthreshold dynamics of the membrane potentials of neocortical neurons during ripples. We patch-clamped layer 2/3 pyramidal cells in the posterior parietal cortex (PPC), a neocortical region that is involved in allocentric spatial representation of behavioral exploration and sequential series of relevant action potentials during ripples. We simultaneously monitored the membrane potentials of post hoc-identified PPC neurons and the local field potentials of the hippocampus in anesthetized mice. More than 50% of the recorded PPC neurons exhibited significant depolarizations and/or hyperpolarizations during ripples. Histological inspections of the recorded neurons revealed that the ripple-modulated PPC neurons were distributed in the PPC in a spatially non-biased fashion. These results suggest that hippocampal ripples are widely but selectively associated with the subthreshold dynamics of the membrane potentials of PPC neurons even though there is no monosynaptic connectivity between the hippocampus and the PPC.
Agreement between heart rate deflection point and maximal lactate steady state in young adults with different body masses
Authors: Afroundeh R. , Hofmann P. , Esmaeilzadeh S. , Narimani M. , Pesola A.J.
Published: March 2021

We examined the agreement between heart rate deflection point (HRDP) variables with maximal lactate steady state (MLSS) in a sample of young males categorized to different body mass statuses using body mass index (BMI) cut-off points. One hundred and eighteen young males (19.9 ± 4.4 years) underwent a standard running incremental protocol with individualized speed increment between 0.3 and 1.0 km/h for HRDP determination. HRDP was determined using the modified Dmax method called S.Dmax. MLSS was determined using 2-5 series of constant-speed treadmill runs. Heart rate (HR) and blood lactate concentration (La) were measured in all tests. MLSS was defined as the maximal running speed yielding a La increase of less than 1 mmol/L during the last 20 min. Good agreement was observed between HRDP and MLSS for HR for all participants (±1.96; 95% CI = −11.5 to +9.2 b/min, ICC = 0.88; P < 0.001). Good agreement was observed between HRDP and MLSS for speed for all participants (±1.96; 95% CI = −0.40 to +0.42 km/h, ICC = 0.98; P < 0.001). The same findings were observed when participants were categorized in different body mass groups. In conclusion, HRDP can be used as a simple, non-invasive and time-efficient method to objectively determine submaximal aerobic performance in nonathletic young adult men with varying body mass status, according to the chosen standards for HRDP determination.
Challenges of a mature Russian field's redevelopment – Advantages and disadvantages of quick-look geologic modeling
Authors: Nemes István , Sebők Szilvia Szilágyi , Csató István
Published: March 2021

Due to the global oil price crisis in 2014, one of the MOL's preventive/reactive measures was to identify geologically or commercially risky elements within their portfolio. This involved reevaluation of all geologic data from Field A in the Volga-Urals Basin. In re-evaluating Field A, several unexpected challenges, problems and pitfalls were faced by the interdisciplinary team performing the task of building a new database, quality checking, and interpreting data dating back to 1947. To overcome these challenges related to this mature field, new approaches and fit-for-purpose methods were required in order to achieve the overall goal of obtaining a reliable estimation of remaining hydrocarbon potential. In the first phase a first-pass 3D geologic model was constructed, along with wrangling, cleaning and interpreting 70 years of subsurface data. This paper focuses on the main challenges involved in evaluating or reevaluating reservoir aspects of a mature field.

The primary challenges were related to the estimation of remaining in-place hydrocarbon volumes, the optimization of infill well placement, the identification of primary and secondary well targets, the identification of critical data gaps, and the planning of new data acquisitions. The hands-on experience gained during the development of the geologic model provided invaluable information for the next steps needed in the redevelopment of the field.
Prediction and numerical simulation of residual stress in multi-pass pipe welds
Authors: Hasan Al-Hafadhi Mahmood , Krallics Gyorgy
Published: March 2021

A numerical simulation procedure is presented to predict residual stress states in multi-pass welds in oil transportation pipes. In this paper, a two-dimensional thermo-mechanical finite element model is used to calculate the temperature distribution, hardness, and the distribution of residual stresses during multi-pass welding of pipes of dissimilar metals and varying thicknesses. In this model, the temperature dependence of the thermal and mechanical properties of the material was considered. The present model was validated using the hardness measurement. Good agreement was found between the measurement and the numerical simulation results. The simulated result shows that the two-dimensional model can be effectively used to simulate the hardness test and predict the residual stress in the pipe weld. The simulation results and measurements suggest that the model with moving heat source can obtain a good prediction of residual welding stress. Both the two-dimensional and the three-dimensional modeling can be used to estimate the residual stresses in different weld regions and help saving time.
Rola krajowej infrastruktury gazowej w kształtowaniu współczesnego bezpieczeństwa energetycznego Polski
Authors:   Katedra Geografii Ekonomicznej, Szkoła Główna Handlowa w Warszawie, Polska, Mróz Maciej
Published: March 2021

The article discusses the impact of the gas infrastructure on the current energy security of Poland. In this context, the subject of the analysis is the natural gas as a low-emission intermediate fuel and the elements of the Polish gas infrastructure responsible for Poland's energy security. The main goal of the article is to try to answer the question: how to form Poland's current and future energy security in the field of gas infrastructure? The whole analysis has been conducted from the national and regional perspective.