bluuebunny/crossref_metadata_2025 huggingface dataset:
VLOGA VOJSK V EVROPI: OD OBRAMBE OZEMLJA K RAZNOVRSTNIM VARNOSTNIM NALOGAM
Authors: VEGIČ VINKO
Published: February 2021

Spreminjanje vloge vojsk v evropskih državah pod vplivom dogajanj po hladni vojni postavlja številna vprašanja tako na teoretični kot na praktični ravni. Na spremembo vloge vojsk pomembno vplivajo predvsem ozemeljska (pre)razporeditev konfrontacij in konfliktov, spreminjanje podobe oboroženih konfliktov ter povečanje pripravljenosti zahodnih držav za vojaško posredovanje v soseščini. Prispevek obravnava teoretična razmišljanja o vlogi vojsk v evropskih državah, prikaže pa tudi nekatere analitične poglede na vlogo vojsk v okviru Nata in EU. Najbolj pomembna sprememba glede vloge vojsk je zmanjševanje potrebe po obrambi ozemlja ter pojav precej različnih in pogosto nejasno definiranih nalog. Tem spremembam pa morajo države prilagoditi tudi obrambne doktrine ter strukturo vojsk. Postopno slovo od ozemeljske obrambne vloge vojske za oblikovalce obrambne politike odpira vrsto vprašanj tako glede odnosa med vojsko in njenim družbenim okoljem kot tudi glede njene notranje organiziranosti. The changing roles of armed forces in European countries, which are influenced by the post- Cold War developments, have opened many questions both, on the theoretical and practical level. The role of the armed forces is influenced mostly by: the territorial (re)location of confrontations and conflicts, the changing feature of armed conflicts and increased willingness of Western states to intervene in their neighbourhood. The article discusses theoretical considerations on the role of armed forces in European countries and presents also some analytical views on the role of armed forces military roles in the framework of NATO and EU. The most important change concerning the role of armed forces is a diminishing need for territorial defence and the emergence of different and frequently vaguely defined tasks of European states’ armed forces. These changes require also the adaptation of defence doctrines and military structure. A gradual farewell to the territorial defence function of the armed forces raises numerous questions for defence policy-makers, which concern the relations between the armed forces and their social environment as well as the military internal organisational structure.
CONTEMPORARY CHALLENGES IN MILITARY EDUCATION – MACEDONIAN MILITARY ACADEMY IN THE CONTEXT
Authors: ANGELEVSKI SLAVKO , Hadji-Janev Metodi
Published: February 2021

This paper evaluates latest reforms in the Macedonian military education system. Both, contemporary challenges in military education and Euro-Atlantic commitment have shaped transformation of military education and training system in the Republic of Macedonia. Hence, these dynamics urged the redefinition of the role and responsibilities of the Military Academy “General Mihailo Apostolski” – Skopje. As a result, today, the Military Academy educates, trains and produces young military and civilian leaders ready to meet contemporary security challenges that affect the defence system, crisis management and disaster risk reduction sector, not only in Macedonia, but in the region of South East Europe as well. The paper explains how the education curricula at the Military Academy reconcile with the European credit transfer system’s requirements on the one hand, and the principles of modern warfare and security challenges on the other. In addition, the paper touches on gender issues in military education, and implementation of information technology in military education.

V članku so vrednotene nedavne reforme sistema makedonskega vojaškega izobraževanja. Tako sodobni izzivi vojaškega izobraževanja kot evroatlantska zaveza so oblikovali proces transformacije sistema vojaškega izobraževanja in usposabljanja v Republiki Makedoniji. Ta dinamika je zahtevala ponovno opredelitev vloge in pristojnosti Vojaške akademije Generala Mihaila Apostolskega v Skopju. Vojaška akademija danes izobražuje, usposablja in ustvarja mlade vojaške in civilne voditelje, ki so se sposobni spopasti s sodobnimi varnostnimi izzivi, ki vplivajo na obrambni sistem in krizno upravljanje ter sektor za zmanjševanje tveganja nesreč, ne le v Makedoniji, temveč tudi v Jugovzhodni Evropi. Razloženo je tudi, kako je načrt izobraževanja Vojaške akademije usklajen z zahtevami evropskega sistema za prenašanje kreditnih točk in z načeli modernega vojskovanja in varnostnimi izzivi. Poleg tega se članek dotakne tudi vprašanja enakosti spolov ter uvajanja informacijske tehnologije v vojaško izobraževanje.
NATO PO LETU 2014
NAZAJ H KORENINAM ALI NAPREJ V PRIHODNOST?
Authors: LAMPRET UROŠ , NOVAK STAŠA
Published: February 2021

Naslov kljub vprašaju in možnosti poenostavljenega razumevanja ne predstavlja nujno dileme o prihodnosti razvoja zavezništva. Nazaj in naprej ne pomenita dveh smeri, temveč bolj združevanje naučenih lekcij in poudarjanje veznega tkiva, ki je Nato skozi zgodovino ohranjalo tako močno, ter opremljanje tega zdravega jedra z mehanizmi, ki nas bodo še naprej ščitili pred celotnim spektrom groženj. Pred tistimi, ki jih poznamo, tistimi, ki jih lahko predvidevamo, ter nekako tudi pred tistimi, ki jih ne moremo predvideti. Pri slednjih je ključna beseda fleksibilnost. V takšnem prikazu lahko prepoznamo daljnovidnost zavezniškega koncepta iz leta 2010, ki kljub pretresom v Vzhodni Evropi in na Bližnjem vzhodu ter s tem povezanim povečanim občutkom ogroženosti v nekaterih zaveznicah ostaja temeljni smerokaz organizaciji tudi za prihodnja leta.
Vračanje h koreninam pomeni zagotavljanje prepričljive pripravljenosti na kolektivno obrambo, usmeritev v prihodnost pa možnost uporabe zmogljivosti za obrambo pred spektrom različnih groženj in izvajanje drugih temeljnih nalog zavezništva. Za zagotavljanje verodostojnosti organizacije ni nujna revolucija, temveč preprosta izpolnitev preteklih zavez za zagotavljanje zmogljivosti. Prav s tem so imele članice veliko težav in ravno njihova počasnost je negativno vplivala na zavezniško verodostojnost. S tega vidika je lahko rusko-ukrajinska dinamika samo priložnost za obrambne sisteme, da opozorijo politične elite na pomen obrambe in dejstvo, da ta stane.
REPUBLIC OF SLOVENIA IN NATO – SLOVENIAN ARMED FORCES TEN YEARS LATER
Authors: OSTERMAN ANDREJ
Published: February 2021

The Republic of Slovenia has now been a member of NATO for ten years, and the membership has significantly contributed to the development of the Slovenian Armed Forces (SAF) which has gained international recognition. By participating in international operations and missions, the SAF also contributes to international security. Since the time of its formation, it has been transforming and adapting to new realities and contemporary security challenges, effectively utilizing the available human and material resources in order to provide the necessary military capabilities. It participates in international military exercises and operates in NATO and EU bodies and commands. Both in NATO and the Slovenian Armed Forces, interconnected transformation processes are currently under way. Some solutions that aim to deliver and develop the necessary military capabilities are being provided through participation in Smart Defence projects, the Connected Forces Initiative and the Framework Nations Concept. In recent years, the SAF has been faced with the continuous reduction of financial resources, which hinders the development of military capabilities. In the future, due to the defence budget reductions, it will be necessary to think about the scope and structure of the SAF and provide stable funding.
REPUBLIKA SLOVENIJA V NATU – SLOVENSKA VOJSKA DESET LET POZNEJE
Authors: OSTERMAN ANDREJ
Published: February 2021

Republika Slovenija je že deset let članica Nata in članstvo v zavezništvu je znatno prispevalo k razvoju Slovenske vojske. Postala je mednarodno prepoznavna. S sodelovanjem v mednarodnih operacijah in na misijah prispeva tudi k mednarodni varnosti. Od svojega nastanka se preoblikuje in prilagaja novim razmeram ter sodobnim varnostnim izzivom, tako da lahko učinkovito uporabi kadrovske in materialne vire, ki so na voljo za zagotavljanje vojaških zmogljivosti. Sodeluje v mednarodnih vojaških vajah in deluje v Natu in organih ter poveljstvih EU. V Natu in Slovenski vojski potekajo transformacijski procesi, ki so med seboj povezani. Nekatere rešitve za zagotavljanje in razvoj vojaških zmogljivosti se zagotavljajo s sodelovanjem v projektih pametne obrambe, konceptu povezanih sil in konceptu vodilne države. Slovenska vojska se v zadnjih letih srečuje z nenehnim zmanjševanjem finančnih virov, kar otežuje razvoj vojaških zmogljivosti. Zaradi krčenja obrambnega proračuna bo v prihodnosti treba opraviti razmislek o prihodnjih obsegu in strukturi Slovenske vojske ter zagotoviti stabilno financiranje.
NORMATIVNA VLOGA ZAVEZNIŠTVA
PRI NEKONVENCIONALNIH VARNOSTNIH GROŽNJAH – KIBERNETIČNA OBRAMBA ČLANIC
Authors: DVORŠAK ADRIJANA
Published: February 2021

Vloga mednarodnih varnostnih organizacij je oblikovanje konsenza o vrednotah, normah in pravilih, ki se nanašajo na kibernetsko bojevanje. Nato proizvaja kibernetske politike, skrbi za izobraževanje in izmenjavo informacij, tudi s publicistično dejavnostjo, nekoliko manj pa je razvil operativne zmogljivosti za skupno kibernetsko obrambo in kibernetsko bojevanje.
V Natu lahko pričakujemo pobude za tesno sodelovanje pri kibernetski obrambi in gradnji skupnih kibernetskih zmogljivosti, kar je racionalen odgovor na nekonvencionalne grožnje. Pridobitve članic, ki bodo izšle iz sodelovanja na področju kibernetskega bojevanja, se bodo med seboj razlikovale. Največ pridobitev avtorica pripisuje ZDA, ker je njihova ekonomija najbolj odvisna od informacijsko-komunikacijskih tehnologij, najbolj globalizirana in domnevno najpogostejša tarča kibernetskih napadov.
Laparoscopic Evaluation of Tubal Factors in Case of Patients With Sub Fertility
Authors: Adhikary Indrani , Banu Jesmine , Sultana Parveen , Chowdhury ASM Alambir , Fatima Parveen
Published: February 2021

In this prospective study was carried out in the department of Obstetrics and Gynaecology (infertility) Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, during the period of September 2010 to February 2011. For this purpose total number of 80 female partner of subfertile couples undergoing laparoscopy in the above centre. Patients have been evaluated in the infertililty out patient department with the detailed history of both husband and wife and also evaluated clinically. Patient suffering from both primary and secondary subfertility have been included in this study with the inclusion criteria women age 20-40 years. Male partners having normal semen analysis. Female partner tried unsuccessfully for 1 year and female partner having any pelvic pathology suggest by history and physical examination. They are selected for the diagnostic laparoscopy. Laparoscopy findings will be carefully recorded and showing in primary subfertility normal looking 30 (55.5%), peritubal adhesion 8(14.8%), signs of endometriosis 10 (18.5%), hydrosalphinx 6(11.1%) and in secondary subfertility normal looking 10(38.5%), peritubal adhesion 4(15.4%), signs of endometriosis 4(15.4%), hydrosalphinx 8(30.8%). In this study normal looking fallopian tube is more common in primary subfertility and hydrosalphinx is more common in secondary subfertility. Laparoscopic evaluation of fallopian tube among the patient with primary subfertility showing the condition of the fimbria normal looking 50 (92.6%), indrowing 2(3.7%), not visualized fimbria 2(3.7%) and in secondary subfertility normal looking 18(69.2%), indrowing 6 (23.1%), not visualized fimbria 2(7.7%). Fimbria normal looking more in primary subfertility and indrawing more in secondary subfertility. In peritubal adhesion 34pt among them 30(88.2%) are dye test negative. In endometriosis 30 patients among them 12(40%) are dye test negative. In pulmonary TB, salphingitis and ectopic pregnancy (100%) are dye test negative.  In tubal patency test of the study patients were observed in case of primary and secondary subfertility. In primary subfertility both tube patent 24(44.4%), unilateral block 20(37%) and bilateral block 10 (18.5%) and in secondary subfertility both tube patent 12 (46.2%), unilateral block 8 (30.8%), bilateral block 6 (23.1%). Bilateral block more in secondary subfertility. No difference in case of both tube patent.

JCMCTA 2012; 23(1): 17-20
IL-4 and IL-17 Are Required for House Dust Mite-Driven Airway Hyperresponsiveness in Autoimmune Diabetes-Prone Non-Obese Diabetic Mice
Authors: Foray Anne-Perrine , Dietrich Céline , Pecquet Coralie , Machavoine François , Chatenoud Lucienne , Leite-de-Moraes Maria
Published: February 2021

Allergic asthma is characterized by airway inflammation with a Th2-type cytokine profile, hyper-IgE production, mucus hypersecretion, and airway hyperreactivity (AHR). It is increasingly recognized that asthma is a heterogeneous disease implicating complex immune mechanisms resulting in distinct endotypes observed in patients. In this study, we showed that non-obese diabetic (NOD) mice, which spontaneously develop autoimmune diabetes, undergo more severe allergic asthma airway inflammation and AHR than pro-Th2 BALB/c mice upon house dust mite (HDM) sensitization and challenge. The use of IL-4-deficient NOD mice and the in vivo neutralization of IL-17 demonstrated that both IL-4 and IL-17 are responsible by the exacerbated airway inflammation and AHR observed in NOD mice. Overall, our findings indicate that autoimmune diabetes-prone NOD mice might become useful as a new HDM-induced asthma model to elucidate allergic dysimmune mechanisms involving Th2 and Th17 responses that could better mimic some asthmatic endoytpes.
Expected and Experienced Social Impact of Host Residents During Rugby World Cup 2019: A Panel Data Approach
Authors: Oshimi Daichi , Yamaguchi Shiro , Fukuhara Takayuki , Taks Marijke
Published: February 2021

Most social impact research considers the pre- and post-event social impacts of sporting events to investigate the effects of these events on residents' or consumers' intention or attitude. This study focused on the qualitative differences between pre-event expected social impacts (T1) and post-event experienced social impacts (T2). Then, it investigated viewing behaviors due to the expected social impacts, and intentions to support events from experienced social impacts. The Rugby World Cup 2019 in Japan provided the context for the study. Panel data were collected from the same Tokyo residents in T1 (3 months before the event) and T2 (4 months after the event). The Internet-based survey consisted of six social impact constructs, framed as expectations in T1 and experiences in T2. Both dependent variables, viewing behavior and supporting events, were measured in T2, after the event occurred. Two expected impacts had a significant positive association with viewing behavior, while three experienced social impacts had a significant positive association with event support intention. The main contribution of this article is extending the understanding of the role of social impact as a predictor variable for residents' behavior and intention to support events by using panel data, which enabled the authors to obtain more robust results. The current study extends the knowledge on consumer expectancy role and social exchange theory in the context of the social impacts of sporting events.
A Protein Assembly Hypothesis for Population-Specific Decrease in Dementia with Time
Authors: Serwer Philip , Wright Elena T.
Published: February 2021

A recent report in the journal, Neurology, documents age-normalized, nation-specific (e.g., United States and Western Europe), progressive decrease of dementia, beginning about 25 years ago. This observation has, thus far, not had explanation. We begin our proposed explanation with the following previous disease construct. (1) Some dementia is caused by innate immune over-response to infections. (2) The innate immune over-response occurs via excessive conversion of amyloid protein to α-sheet conformation. (3) This conversion evolved to inhibit invading microbes by binding microbe-associated α-sheet, e.g., in hyper-expanded capsid intermediates of some viruses. The rarity of human α-sheet makes this inhibition specific for microbial invaders. As foundation, here we observe directly, for the first time, extreme, sheet-like outer shell thinness in a hyper-expanded capsid of phage T3. Based on phage/herpesvirus homology, we propose the following. The above decrease in dementia is caused by varicella-zoster virus (VZV) vaccination, USFDA-approved about 25 years ago; VZV is a herpesvirus and causes chickenpox and shingles. In China and Japan, a cotemporaneous non-decrease is explained by lower anti-VZV vaccination. Co-assembly extension of α-sheet is relatively independent of amino acid sequence. Thus, we project that additional dementia is suppressible by vaccination against other viruses, including other herpesviruses.
Development of Roughness Prediction Models for Laos National Road Network
Authors: Gharieb Mohamed , Nishikawa Takafumi
Published: February 2021

The International Roughness Index (IRI) has been accepted globally as an essential indicator for assessing pavement condition. The Laos Road Management System (RMS) utilizes a default Highway Development and Management (HDM-4) IRI prediction model. However, developed IRI values have shown the need to calibrate the IRI prediction model. Data records are not fully available for Laos yet, making it difficult to calibrate IRI for the local conditions. This paper aims to develop an IRI prediction model for the National Road Network (NRN) based on the available Laos RMS database. The Multiple Linear Regression (MLR) analysis technique was applied to develop two new IRI prediction models for Double Bituminous Surface Treatment (DBST) and Asphalt Concrete (AC) pavement sections. The final database consisted of 83 sections with 269 observations over a 1850 km length of DBST NRN and 29 sections with 122 observations over a 718 km length of AC NRN. The proposed models predict IRI as a function of pavement age and Cumulative Equivalent Single-Axle Load (CESAL). The model’s parameter analysis confirmed their significance, and R2 values were 0.89 and 0.84 for DBST and AC models, respectively. It can be concluded that the developed models can serve as a useful tool for engineers maintaining paved NRN.
Validation and Use of the RumiWatch Noseband Sensor for Monitoring Grazing Behaviours of Lactating Dairy Cows
Authors: Li Zelin , Cheng Long , Cullen Brendan
Published: February 2021

Precision livestock farming (PLF) supports the development of sustainable dairy production. The sensors used in PLF provide valuable information for farm management, but they must be validated to ensure the accuracy. The goal of this study was to validate and use the RumiWatch sensor (RWS; Itin+Hoch GmbH, Liestal, Switzerland) to differentiate prehension bites, eating chews, mastication chews and rumination chews in pressure-based system. Twenty cows were used for 14 days to provide a validation dataset. The concordance correlation coefficient (CCC) was adopted to test the concordance between the RumiWatch sensor and video observation. The RumiWatch sensor performed well in counting prehension bites (CCC = 0.98), eating chews (CCC = 0.95) and rumination chews (CCC = 0.96), while it showed an acceptable concordance in counting mastication chews with video observation (CCC = 0.77). Moderate correlations were found between eating chews and daily milk production: daily milk production (kg/day) = 0.001151 × eating chews (chews/day) − 11.73 (R2 = 0.31; standard error (SE) = 8.88; p = 0.011), and between mastication chews and daily milk production: daily milk production (kg/day) = 0.001935 × mastication chews (chews/day) + 2.103 (R2 = 0.34; SE = 8.70; p = 0.007). Overall, the results indicated that the RumiWatch sensor can be confidently used to quantify and differentiate prehension bites, eating chews and rumination chews; in addition, ingestive behaviours explained up to 34% of the variation in milk production.
The State of the Art in Methodologies of Course Recommender Systems—A Review of Recent Research
Authors: Guruge Deepani B. , Kadel Rajan , Halder Sharly J.
Published: February 2021

In recent years, education institutions have offered a wide range of course selections with overlaps. This presents significant challenges to students in selecting successful courses that match their current knowledge and personal goals. Although many studies have been conducted on Recommender Systems (RS), a review of methodologies used in course RS is still insufficiently explored. To fill this literature gap, this paper presents the state of the art of methodologies used in course RS along with the summary of the types of data sources used to evaluate these techniques. This review aims to recognize emerging trends in course RS techniques in recent research literature to deliver insights for researchers for further investigation. We provide a systematic review process followed by research findings on the current methodologies implemented in different course RS in selected research journals such as: collaborative, content-based, knowledge-based, Data Mining (DM), hybrid, statistical and Conversational RS (CRS). This study analyzed publications between 2016 and June 2020, in three repositories; IEEE Xplore, ACM, and Google Scholar. These papers were explored and classified based on the methodology used in recommending courses. This review has revealed that there is a growing popularity in hybrid course RS and followed by DM techniques in recent publications. However, few CRS-based course RS were present in the selected publications. Finally, we discussed future avenues based on the research outcome, which might lead to next-generation course RS.
Electrical and Thermomechanical Co-Simulation Platform for NPP
Authors: Astero Poria , Laakso Pasi , Hänninen Seppo , Millar Robert , Lehtonen Matti
Published: February 2021

In order to analyze the safety of nuclear power plants (NPP), interactions between thermomechanical and automation processes, the on-site electrical grid, and the off-site transmission system should be studied in detail. However, an initial survey of simulation tools used for the modelling and simulation of NPP shows that existing simulation tools have some drawbacks in properly simulating the aforementioned interactions. In fact, they simulate detailed electrical power systems and thermomechanical systems but neglect the detailed interactions of the electrical system with thermomechanical and automation processes. To address this challenge, this paper develops an open-source co-simulation platform which connects Apros, a proprietary simulator of the thermomechanical and automation processes in NPP, to power system simulators. The proposed platform provides an opportunity to simulate both the electrical and thermomechanical systems of an NPP simultaneously, and study the interactions between them without neglecting any details. This detailed analysis can identify critical faults more accurately, and provides better support for probabilistic risk analyses (PRA) of NPP. To investigate the effectiveness of the proposed platform, detailed thermomechanical and electrical models of an NPP, located in Finland, are cosimulated. The preliminary results emphasize that neglecting the detailed interactions between domains of NPP may lead to inaccurate simulation results and may affect NPP safety.
Survival, Growth, and Development in the Early Stages of the Tropical Gar Atractosteus tropicus: Developmental Critical Windows and the Influence of Temperature, Salinity, and Oxygen Availability
Authors: Martínez Gil , Peña Emyr , Martínez Rafael , Camarillo Susana , Burggren Warren , Álvarez Alfonso
Published: February 2021

Alterations in fish developmental trajectories occur in response to genetic and environmental changes, especially during sensitive periods of development (critical windows). Embryos and larvae of Atractosteus tropicus were used as a model to study fish survival, growth, and development as a function of temperature (28 °C control, 33 °C, and 36 °C), salinity (0.0 ppt control, 4.0 ppt, and 6.0 ppt), and air saturation (control ~95% air saturation, hypoxia ~30% air saturation, and hyperoxia ~117% air saturation) during three developmental periods: (1) fertilization to hatch, (2) day 1 to day 6 post hatch (dph), and (3) 7 to 12 dph. Elevated temperature, hypoxia, and hyperoxia decreased survival during incubation, and salinity at 2 and 3 dph. Growth increased in embryos incubated at elevated temperature, at higher salinity, and in hyperoxia but decreased in hypoxia. Changes in development occurred as alterations in the timing of hatching, yolk depletion, acceptance of exogenous feeding, free swimming, and snout shape change, especially at high temperature and hypoxia. Our results suggest identifiable critical windows of development in the early ontogeny of A. tropicus and contribute to the knowledge of fish larval ecology and the interactions of individuals × stressors × time of exposure.
Numerical Study on an Interface Compression Method for the Volume of Fluid Approach
Authors: Okagaki Yuria , Yonomoto Taisuke , Ishigaki Masahiro , Hirose Yoshiyasu
Published: February 2021

Many thermohydraulic issues about the safety of light water reactors are related to complicated two-phase flow phenomena. In these phenomena, computational fluid dynamics (CFD) analysis using the volume of fluid (VOF) method causes numerical diffusion generated by the first-order upwind scheme used in the convection term of the volume fraction equation. Thus, in this study, we focused on an interface compression (IC) method for such a VOF approach; this technique prevents numerical diffusion issues and maintains boundedness and conservation with negative diffusion. First, on a sufficiently high mesh resolution and without the IC method, the validation process was considered by comparing the amplitude growth of the interfacial wave between a two-dimensional gas sheet and a quiescent liquid using the linear theory. The disturbance growth rates were consistent with the linear theory, and the validation process was considered appropriate. Then, this validation process confirmed the effects of the IC method on numerical diffusion, and we derived the optimum value of the IC coefficient, which is the parameter that controls the numerical diffusion.
A Lamination Model for Pressure-Assisted Sintering of Multilayered Porous Structures
Authors: Jin Zhi-He , Cramer Corson L.
Published: February 2021

This work describes a lamination model for pressure-assisted sintering of thin, multilayered, and porous structures based on the linear viscous constitutive theory of sintering and the classical laminated plate theory of continuum mechanics. A constant out-of-plane normal stress is assumed in the constitutive relation. The lamination relations between the force/moment resultants and the strain/curvature rates are presented. Numerical simulations were performed for a symmetric tri-layer laminate consisting of a 10% gadolinia doped ceria (Ce0.9Gd0.1O1.95-δ) composite structure, where porous layers were adhered to the top and bottom of a denser layer under uniaxially-applied pressures and the sinter forging conditions. The numerical results show that, compared with free sintering, the applied pressure can significantly reduce the sintering time required to achieve given layer thicknesses and porosities. Unlike free sintering, which results in a monotonic decrease of the laminate in-plane dimension, pressure-assisted sintering may produce an in-plane dimension increase or decrease, depending on the applied pressure and sintering time. Finally, the individual layers in the laminate exhibit different stress characteristics under pressure-assisted sintering.
Numerical Analysis of Filament Wound Cylindrical Composite Pressure Vessels Accounting for Variable Dome Contour
Authors: Jois Kumar C. , Welsh Marcus , Gries Thomas , Sackmann Johannes
Published: February 2021

In this work, the stress distribution along cylindrical composite pressure vessels with different dome geometries is investigated. The dome contours are generated through an integral method based on shell stresses. Here, the influence of each dome contour on the stress distribution at the interface of the dome-cylinder is evaluated. At first, the integral formulation for dome curve generation is presented and solved for the different dome contours. An analytical approach for the calculation of the secondary stresses in a cylindrical pressure vessel is introduced. For the analysis, three different cases were investigated: (i) a polymer liner; (ii) a single layer of carbon-epoxy composite wrapped on a polymer liner; and (iii) multilayer carbon-epoxy pressure vessel. Accounting for nonlinear geometry is seen to have an effect on the stress distribution on the pressure vessel, also on the isotropic liner. Significant secondary stresses were observed at the dome-cylinder interface and they reach a maximum at a specific distance from the interface. A discussion on the trend in these stresses is presented. The numerical results are compared with the experimental results of the multilayer pressure vessel. It is observed that the secondary stresses present in the vicinity of the dome-cylinder interface has a significant effect on the failure mechanism, especially for thick walled cylindrical composite pressure vessel. It is critical that these secondary stresses are directly accounted for in the initial design phase.
Regional Differences in Biceps Femoris Long Head Stiffness during Isometric Knee Flexion
Authors: Vaz João R. , Neto Tiago , Correia José Pedro , Infante Jorge , Freitas Sandro R.
Published: February 2021

This study sought to investigate whether the stiffness of the biceps femoris long head differs between proximal and distal regions during isometric knee flexion at different contraction intensities and muscle lengths. Twelve healthy individuals performed knee flexion isometric contractions at 20% and 60% of maximum voluntary isometric contraction, with the knee flexed at 15 and 45 degrees. Muscle stiffness assessment was performed using ultrasound-based shear wave elastography. Proximal and distal regions of the biceps femoris long head were assessed. Biceps femoris long head muscle showed a greater stiffness (i) in the distal region, (ii) at higher contraction intensity, and (iii) at longer muscle length. The proximal-to-distal stiffness ratio was significantly lower than 1 (i.e., heterogenous) at lower contraction intensity regardless of the muscle length. However, this was not observed at higher contraction intensity. This study is the first to show heterogeneity in the active stiffness of the biceps femoris long head. Given the greater incidence of injury at the proximal region of biceps femoris long head, this study opens new directions for future research. Additionally, the present study results indicate that studies assessing muscle stiffness at one single muscle region should be interpreted with caution.
No Matter What Images You Share, You Can Probably Be Fingerprinted Anyway
Authors: Rouhi Rahimeh , Bertini Flavio , Montesi Danilo
Published: February 2021

The popularity of social networks (SNs), amplified by the ever-increasing use of smartphones, has intensified online cybercrimes. This trend has accelerated digital forensics through SNs. One of the areas that has received lots of attention is camera fingerprinting, through which each smartphone is uniquely characterized. Hence, in this paper, we compare classification-based methods to achieve smartphone identification (SI) and user profile linking (UPL) within the same or across different SNs, which can provide investigators with significant clues. We validate the proposed methods by two datasets, our dataset and the VISION dataset, both including original and shared images on the SN platforms such as Google Currents, Facebook, WhatsApp, and Telegram. The obtained results show that k-medoids achieves the best results compared with k-means, hierarchical approaches, and different models of convolutional neural network (CNN) in the classification of the images. The results show that k-medoids provides the values of F1-measure up to 0.91% for SI and UPL tasks. Moreover, the results prove the effectiveness of the methods which tackle the loss of image details through the compression process on the SNs, even for the images from the same model of smartphones. An important outcome of our work is presenting the inter-layer UPL task, which is more desirable in digital investigations as it can link user profiles on different SNs.
Wildfire Smoke Exposure: Covid19 Comorbidity?
Authors: Leifer Ira , Kleinman Michael T. , Blake Donald , Tratt David , Marston Charlotte
Published: February 2021

Air pollution, particularly fine and ultrafine particulate matter aerosols, underlies a wide range of communicable and non-communicable disease affecting many systems including the cardiopulmonary and immune systems, and arises primarily from transportation and industry. A number of air pollution driven diseases also are Covid19 comorbidities. Thus, a number of studies on air pollution exposure, particularly particulate matter, strongly indicate air pollution is an important underlying factor in Covid19 transmission, severity, and mortality. This suggests that air pollution from natural sources, particularly wildfires, could play a role in the Covid19 pandemic. We tested this hypothesis on three wildfire smoke events in Orange County, CA, each of which was followed by Covid19 case increases after an approximately one-week lag. This lag was consistent with combined incubation time and testing/reporting times. Moreover, the three events suggest a dose dependency. The wildfire comorbidity hypothesis implies that at-risk-populations should reduce smoke exposure from wildfires, as well as indoors from biomass burning for heating, cooking, and aesthetic purposes.
Custom-Made Zirconium Dioxide Implants for Craniofacial Bone Reconstruction
Authors: Kozakiewicz Marcin , Gmyrek Tomasz , Zajdel Radosław , Konieczny Bartłomiej
Published: February 2021

Reconstruction of the facial skeleton is challenging for surgeons because of difficulties in proper shape restoration and maintenance of the proper long-term effect. ZrO2 implant application can be a solution with many advantages (e.g., osseointegration, stability, and radio-opaqueness) and lacks the disadvantages of other biomaterials (e.g., metalosis, radiotransparency, and no osseointegration) or autologous bone (e.g., morbidity, resorption, and low accuracy). We aimed to evaluate the possibility of using ZrO2 implants as a new application of this material for craniofacial bone defect reconstruction. First, osteoblast (skeleton-related cell) cytotoxicity and genotoxicity were determined in vitro by comparing ZrO2 implants and alumina particle air-abraded ZrO2 implants to the following: 1. a titanium alloy (standard material); 2. ultrahigh-molecular-weight polyethylene (a modern material used in orbital surgery); 3. a negative control (minimally cytotoxic or genotoxic agent action); 4. a positive control (maximally cytotoxic or genotoxic agent action). Next, 14 custom in vivo clinical ZrO2 implants were manufactured for post-traumatologic periorbital region reconstruction. The soft tissue position improvement in photogrammetry was recorded, and clinical follow-up was conducted at least 6 years postoperatively. All the investigated materials revealed no cytotoxicity. Alumina particle air-abraded ZrO2 implants showed genotoxicity compared to those without subjection to air abrasion ZrO2, which were not genotoxic. The 6-month and 6- to 8-year clinical results were aesthetic and stable. Skeleton reconstructions using osseointegrated, radio-opaque, personalized implants comprising ZrO2 material are the next option for craniofacial surgery.
Recent Attempts in the Design of Efficient PVC Plasticizers with Reduced Migration
Authors: Czogała Joanna , Pankalla Ewa , Turczyn Roman
Published: February 2021

This paper reviews the current trends in replacing commonly used plasticizers in poly(vinyl chloride), PVC, formulations by new compounds with reduced migration, leading to the enhancement in mechanical properties and better plasticizing efficiency. Novel plasticizers have been divided into three groups depending on the replacement strategy, i.e., total replacement, partial replacement, and internal plasticizers. Chemical and physical properties of PVC formulations containing a wide range of plasticizers have been compared, allowing observance of the improvements in polymer performance in comparison to PVC plasticized with conventionally applied bis(2-ethylhexyl) phthalate, di-n-octyl phthalate, bis(2-ethylhexyl) terephthalate and di-n-octyl terephthalate. Among a variety of newly developed plasticizers, we have indicated those presenting excellent migration resistance and advantageous mechanical properties, as well as those derived from natural sources. A separate chapter has been dedicated to the description of a synergistic effect of a mixture of two plasticizers, primary and secondary, that benefits in migration suppression when secondary plasticizer is added to PVC blend.
A Non-Geodesic Trajectory Design Method and Its Post-Processing for Robotic Filament Winding of Composite Tee Pipes
Authors: Chang Cheng , Han Zhenyu , Li Xinyu , Sun Shouzheng , Qin Jihao , Fu Hongya
Published: February 2021

With the advantages of high specific strength and well corrosion resistance, polymer-matrix composite tee pipes are widely used in aerospace and civilian fields. The robotic filament winding technology is suitable for forming complex shape parts. This paper aims to provide a novel non-geodesic trajectory design method to get a continuous trajectory for tee pipe winding. Furthermore, post-processing methods are proposed for realizing the full coverage of tee pipes by robotic filament winding. The CAD/CAM software is then designed to simulate the winding process and realize the cover of the whole tee pipe. Finally, experiments of winding a tee pipe with a desktop winding machine and a six-axis winding robot are carried out. The results show that the tee pipe is fully covered, verifying the accuracy of the design method and post-processing methods.
Comments on “Dynamic Adsorption of Sulfamethoxazole from Aqueous Solution by Lignite Activated Coke”
Authors: Juela Diego M.
Published: February 2021

This paper presents a brief discussion with regard to the fixed-bed modeling results of a recent paper by Li et al. published in this journal.
Structural Integrity of Steel Pipeline with Clusters of Corrosion Defects
Authors: Witek Maciej
Published: February 2021

The main goal of this paper is to evaluate the burst pressure and structural integrity of a steel pipeline based on in-line inspection results, in respect to the grouping criteria of closely spaced volumetric surface features. In the study, special attention is paid to evaluation of data provided from the diagnostics using an axial excitation magnetic flux leakage technology in respect to multiple defects grouping. Standardized clustering rules were applied to the corrosion pits taken from an in-line inspection of the gas transmission pipeline. Basic rules of interaction of pipe wall metal losses are expressed in terms of longitudinal and circumferential spacing of the features in the colony. The effect of interactions of the detected anomalies on the tube residual strength evaluated according to the Det Norske Veritas Recommended practice was investigated in the current study. In the presented case, groups of closely-spaced defects behaved similarly as individual flaws with regard to their influence on burst pressure and pipeline failure probability.
Synthesis, Bottom up Assembly and Thermoelectric Properties of Sb-Doped PbS Nanocrystal Building Blocks
Authors: Cadavid Doris , Wei Kaya , Liu Yu , Zhang Yu , Li Mengyao , Genç Aziz , Berestok Taisiia , Ibáñez Maria , Shavel Alexey , Nolas George S. , Cabot Andreu
Published: February 2021

The precise engineering of thermoelectric materials using nanocrystals as their building blocks has proven to be an excellent strategy to increase energy conversion efficiency. Here we present a synthetic route to produce Sb-doped PbS colloidal nanoparticles. These nanoparticles are then consolidated into nanocrystalline PbS:Sb using spark plasma sintering. We demonstrate that the introduction of Sb significantly influences the size, geometry, crystal lattice and especially the carrier concentration of PbS. The increase of charge carrier concentration achieved with the introduction of Sb translates into an increase of the electrical and thermal conductivities and a decrease of the Seebeck coefficient. Overall, PbS:Sb nanomaterial were characterized by two-fold higher thermoelectric figures of merit than undoped PbS.
Temperature-Induced Phase Transition Characteristics of [001]-Oriented 0.93Pb(Zn1/3Nb2/3)O3-0.07PbTiO3 (PZN-7%PT) Single Crystal by Using Piezoresponse Force Microscopy
Authors: Wang Hongli , Zeng Kaiyang
Published: February 2021

The evolution of the domain structures of [001]-oriented relaxor ferroelectric 0.93PbZn1/3Nb2/3O3-0.07PbTiO3 (PZN-7%PT) single crystals as a function of temperature was investigated in situ by using piezoresponse force microscopy (PFM). It was found that the local domain structure of PZN-7%PT single crystals at room temperature is rhombohedral with nanoscale twins. Temperature-dependent domain structures showed that the phase transition process is a collective process and that the sample underwent a sequence of rhombohedral (R) → monoclinic (Mc) → tetragonal (T) → cubic (C) phase transformations when the temperature increased from 25 °C to 170 °C. The results provide direct observation of the phase transition evolution of PZN-7%PT single crystals as a function of temperature, which is of great significance to fully understand the relationships between the domain structure and phase structure of PZN-7%PT single crystals.
Fatigue Test of 6082 Aluminum Alloy under Random Load with Controlled Kurtosis
Authors: Owsiński Robert , Niesłony Adam
Published: February 2021

This paper presents the results of experimental tests carried out on an electromagnetic shaker where the excited element was a specimen with additional weight attached to the slip table. The load was random with a different kurtosis parameter value, i.e., it was performed for non-Gaussian loads. The experiment was accompanied by basic fatigue calculations in the frequency domain and their verification with experimental results. A significant decrease in fatigue life was found to take place with an increase in kurtosis and the maintenance of the same standard deviation of the specimen load. The fatigue effect, caused by the deviation from the normal distribution that was described by the kurtosis parameter, on the fatigue life of aluminum alloy 6082 was presented. An analysis revealed the different amplitude probability distributions for the loading signal and the recorded deformation signal. It was concluded that there was a lack of sensitivity of the numerical model to the change in the kurtosis parameter of the distribution of random loads.
Thermal Nonlinear Klein–Gordon Equation for Nano-/Micro-Sized Metallic Particle–Attosecond Laser Pulse Interaction
Authors: Oane Mihai , Mahmood Muhammad Arif , Popescu Andrei C. , Bănică Alexandra , Ristoscu Carmen , Mihăilescu Ion N.
Published: February 2021

In this study, a rigorous analytical solution to the thermal nonlinear Klein–Gordon equation in the Kozłowski version is provided. The Klein–Gordon heat equation is solved via the Zhukovsky “state-of-the-art” mathematical techniques. Our study can be regarded as an initial approximation of attosecond laser–particle interaction when the prevalent phenomenon is photon–electron interaction. The electrons interact with the laser beam, which means that the nucleus does not play a significant role in temperature distribution. The particle is supposed to be homogenous with respect to thermophysical properties. This theoretical approach could prove useful for the study of metallic nano-/micro-particles interacting with attosecond laser pulses. Specific applications for Au “nano” particles with a 50 nm radius and “micro” particles with 110, 130, 150, and 1000 nm radii under 100 attosecond laser pulse irradiation are considered. First, the cross-section is supposed to be proportional to the area of the particle, which is assumed to be a perfect sphere of radius R or a rotation ellipsoid. Second, the absorption coefficient is calculated using a semiclassical approach, taking into account the number of atoms per unit volume, the classical electron radius, the laser wavelength, and the atomic scattering factor (10 in case of Au), which cover all the basic aspects for the interaction between the attosecond laser and a nanoparticle. The model is applicable within the 100–2000 nm range. The main conclusion of the model is that for a range inferior to 1000 nm, a competition between ballistic and thermal phenomena occurs. For values in excess of 1000 nm, our study suggests that the thermal phenomena are dominant. Contrastingly, during the irradiation with fs pulses, this value is of the order of 100 nm. This theoretical model’s predictions could be soon confirmed with the new EU-ELI facilities in progress, which will generate pulses of 100 as at a 30 nm wavelength.
A Facile and Scalable Approach in the Fabrication of Tailored 3D Graphene Foam via Freeze Drying
Authors: Thomas Tony , Agarwal Arvind
Published: February 2021

One of the challenges in the processing of advanced composite materials with 2D reinforcement is their extensive agglomeration in the matrix. 3D architecture of 2D graphene sheets into a Graphene Foam (GrF) assembly has emerged as an effective way to overcome agglomeration. The highly reticulated network of branches and nodes of GrF offers a seamless pathway for photon and electron conduction in the matrix along with improved mechanical properties. 3D GrF nano-filler is often fabricated by chemical vapor deposition (CVD) technique, which demands high energy, slow deposition rate, and restricting production to small scale. This work highlights freeze-drying (FD) technique to produce 3D graphene nanoplatelets (GNP) foam with a similar hierarchical structure to the CVD GrF. The FD technique using water as the main chemical in 3D GNP foam production is an added advantage. The flexibility of the FD in producing GNP foams of various pore size and morphology is elucidated. The simplicity with which one can engineer thermodynamic conditions to tailor the pore shape and morphology is presented here by altering the GNP solid loading and mold geometry. The FD 3D GNP foam is mechanically superior to CVD GrF as it exhibited 1280 times higher elastic modulus. However, thermal diffusivity of the FD GNP foam is almost 0.5 times the thermal diffusivity of the CVD GrF due to the defects in GNP particles and pore architecture. The versatility in GNP foam scalability and compatibility to form foam of other 1D and 2D material systems (e.g., carbon nanotubes, boron nitride nanotubes, and boron nitride nanoplatelets) brings a unique dimensionality to FD as an advanced engineering foam development process.