bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expanded profiling of β-lactam selectivity for penicillin-binding proteins in Streptococcus pneumoniae D39
Authors: Sharan Deepti , Carlson Erin E. 
Published: February 2022

Abstract
Penicillin-binding proteins (PBPs) are integral to bacterial cell division as they mediate the final steps of cell wall maturation. Selective fluorescent probes are useful for understanding the role of individual PBPs, including their localization and activity during growth and division of bacteria. For the development of new selective probes for PBP imaging, several β-lactam antibiotics were screened, as they are known to covalently bind PBP in vivo. The PBP inhibition profiles of 16 commercially available β-lactam antibiotics were evaluated in an unencapsulated derivative of the D39 strain of Streptococcus pneumoniae, IU1945. These β-lactams have not previously been characterized for their PBP inhibition profiles in S. pneumoniae and these data augment those obtained from a library of 20 compounds that we previously reported. We investigated seven penicillins, three carbapenems, and six cephalosporins. Most of these β-lactams were found to be co-selective for PBP2x and PBP3, as was noted in our previous studies. Six out of 16 antibiotics were selective for PBP3 and one molecule was co-selective for PBP1a and PBP3. Overall, this work expands the chemical space available for development of future β-lactam-based probes for specific pneumococcal PBP labeling and these methods can be used for the development of probes for PBP labelling in other bacterial species.
Anisotropic size change during continuous quenching and deep freezing of tool steel *
Authors: Berns H. , Pinto H. 
Published: February 2022

Abstract
The size change of a low carbon maraging steel and of a ledeburitic cold work tool steel produced by ingot (IN) or powder metallurgy (PM) was measured by dilatometry using specimens taken in longitudinal or transverse direction of hot working. The anisotropy of the size change during martensitic transformation ΔεM was negative for the maraging and the PM steel, but positive for the IN steel and the more so, if the cooling rate was raised by injecting liquid nitrogen during quenching to −150 °C. The microstructure and texture was investigated by high resolution SEM equipped with microprobe analysis and respective imaging as well as by EBSD. The results show that Δεis not related to a texture M of the martensitic matrix but to a microstructural banding caused by microsegregation and hot working. The alignment of the eutectic M7 C3 carbides in the direction of hot working coincides with their texture.
Quenching cracks in medium carbon steel initiated at manganese sulfide inclusions
Authors: Temmel C. , Karlsson B. , Ingesten N.-G. 
Published: February 2022

Abstract
Quench crack propensity has been investigated for two identical medium carbon steels (50CrMo4) which only differed in sulfur content. The standard variant of the material was affected by manganese sulfide inclusions whereas the low sulfur material was essentially free of sulfides. 80 mm, cylindrical test specimens were used. The test specimens had been cut out of cross rolled steel plates in which the manganese sulfide were flattened to discoid shape. The specimen orientation was in direction of principal deformation where the flattened sulfides were aligned with the test specimen axis. The largest sulfides reached lengths of 150 μm.
Both materials were austenitized at 850 °C for 60 minutes, quenched in a salt-bath at 180 °C and immediately annealed at 425 °C for one hour. It turned out that the standard material developed quench cracks which initiated at manganese sulfide. No cracks could be found in the low sulfur material. Thermal and transformational stresses, which develop during quenching, aggravate the stress situation around the manganese sulfide and cause the cracking. The results are interpreted in fracture mechanical terms.
Vermeidung von Sperrschichten auf nitrierten Bauteilen – Eine Anleitung zum Handeln
Authors: Blum T. , Chaban M. , Braun R. , Huchel Uwe , Klümper-Westkamp Heinrich 
Published: February 2022

Abstract
Die lebhafte Diskussion zu Fragen der Prozessfähigkeit in der Wärmebehandlung führte bereits im Jahr 2005 beim AWT-Fachausschuss 3, „Nitrieren und Nitrocarburieren“, zur Bildung einer Arbeitsgruppe, die einen Vorschlag zur Festlegung der Prozessfähigkeit für die thermochemischen Wärmebehandlungsverfahren Nitrieren und Nitrocarburieren erarbeitet und veröffentlicht hat. Es wurde gezeigt, dass ganz bestimmte Anforderungen an das Bauteil selbst, den Herstellungsprozess und an die Wärmebehandlungsanlage zu stellen sind. Es ist zwischen einer Prozessfähigkeit der Bauteile und einer Prozessfähigkeit der Anlage zu unterscheiden.
In einer neuen Ausarbeitung „Vermeidung von Sperrschichten auf nitrierten Bauteilen – Eine Anleitung zum Handeln“ hat eine fünfköpfige Arbeitsgruppe sich diesem Thema gewidmet. Das Ergebnis der Arbeit ist in dieser Ausgabe nachfolgend veröffentlicht. Im Internet steht die Anleitung auf der Seite des FA 3 der AWT zum Download bereit.
Schoolchildren’s Right to Education and Freedom of Religion in the Case Law of the ECtHR: Comments on Papageorgiou v Greece
Authors: Milios Georgios 
Published: February 2022

Abstract
The article deals with the schoolchildren’s right to education and freedom of religion in the case law of the ECtHR, with a special focus on the case Papageorgiou v Greece adopted in October 2019. In the case at hand, the applicants challenged the content of the religious courses in Greece as well as the opt-out procedure offered for parents who did not wish their children to participate in the religious course. The Court concluded that the exemption procedure violated Art 2 of Protocol 1 of the ECHR. After examining previous case law of the ECtHR on similar cases, the article focuses on the most striking parts of the Court’s judgment in Papageorgiou. In particular, the ECtHR only considered the exemption procedure from the courses offered, and made no reference to, or examination of, the courses themselves. In addition, the perspective related to the right to private life is also missing. The article concludes by commenting that the Court’s judgment had already had an impact on the case law of the Greek Supreme Administrative Court.
Convicted Individuals as a Group Stigmatised by the State in the Case Law of the Constitutional Court of the Republic of Latvia
Authors: Osipova Sanita 
Published: February 2022

Abstract
This research aims at analysing the Constitutional Court’s case law in respect of restrictions on the fundamental rights of convicted individuals in correlation with society’s view of convicts. To do so, along with the methods of legal science (analysis of legal provisions and case law) the research uses sociological concepts, methods, and sources. The fundamental rights of an individual require the State to protect every individual’s human dignity in equal measure. However, even modern-day society still stigmatises particular groups of individuals, restricting their rights without good reason. The case law of the Constitutional Court of Latvia marks convicted individuals as a stigmatised group with limited rights. In the cases analysed, not even the minimum standards of fundamental rights protecting personal privacy were applied to persons serving a sentence for serious offences, with no individual assessment provided for, because society’s opinion, among other things, denies prisoners such fundamental rights. Furthermore, the convicted individuals may suffer from a life-long stigma as they keep being restricted in their rights – eg the rights to employment or to family life – even after the conviction is expunged. The State has to realise: if it limits the possibilities for convicted individuals to lead life with enjoying full rights, the probability of repeated offences by such individuals will be higher. By unreasonably restricting inclusion of convicted individuals in its life, society endangers rather than protects itself.
Treaties in the Philippine Constitutional System
Authors: Desierto Diane A 
Published: February 2022

Abstract
International law has always had a dual significance to the Philippine constitutional system. On the one hand, the frequent articulation of international law principles within modern Philippine constitutional norms, statutes, and administrative rules demonstrate an outward-looking normative ethos – one I have described in other scholarship to be consistent with the 1987 Philippine Constitution’s ‘universalist history’. On the other hand, the considerable volume of Philippine jurisprudence applying international law norms to date overwhelmingly illustrate how Philippine litigants have strategically deployed international law (most especially international human rights law) over the years, as an acceptable external legal basis to hold Philippine government leaders to account under the vastly expanded judicial review doctrine in the 1987 Philippine Constitution. This active individual and group resort to adjudication and legislation could explain why international law has flourished under the postcolonial and post-dictatorship 1987 Philippine Constitution. This comprehensive jurisprudential, statutory, and constitutional analysis aims to show how, and to what degree, Philippine legal culture and history reflect a continuing deep engagement with international law, in ways that are certainly unique to the Philippines’ evolving political ideologies, colonial and postcolonial history, treatment, and implementation of international treaties within the Philippine constitutional system. Most importantly, the absence of explicit methodology for the breadth of constitutional interpretation of the Incorporation Clause under the 1987 Philippine Constitution warrants normative rethinking, so as not to uniformly open the floodgates to hard international law sources (eg treaties, customs, general principles) as well as softer international instruments lacking the requisite State consent to the binding quality of such sources within the Philippine legal system. To this end, I make three proposals on how the Philippine Supreme Court could define an explicit methodology for use and interpretation of the Incorporation Clause, transparently refer to other foreign and international sources, and openly reassess its ideological bases for recognition of international law in the Philippine constitutional system, as part of the Court’s distinct judicial function.
Corrosion behavior of hydroxyapatite coated AZ31 and AZ91 Mg alloys by electrostatic spray coating
Authors: Baslayici Serkan , Bugdayci Mehmet , Benzesik Kagan , Yucel Onuralp , Acma Mahmut Ercan 
Published: February 2022

Abstract
Magnesium and its alloys are excellent implant material candidates with their biodegradable structure and mechanical properties close to human bone. In order to provide the desired strength in implant applications, the corrosion resistance of the materials is expected to be high. In this study, to improve the corrosion resistance of AZ31 and AZ91 magnesium alloys, an electrostatic hydroxyapatite coating process was applied, and optimum conditions were determined. The samples were structurally characterized by scanning electron microscopy/energy dispersive X-ray spectroscopy and stereo microscopy methods, and their corrosion behavior was determined by the weight loss method. As a result of the coating, the corrosion resistance of the samples increased up to 250 %.
Investigation of the influence of the energy conditions of pulsed plasma-chemical synthesis on the morphological and structural properties of copper-containing silica-based nanocomposites
Authors: Ponomarev Denis , Kholodnaya Galina , Sazonov Roman , Lapteva Olga , Konusov Fedor , Gadirov Ruslan 
Published: February 2022

Abstract
This paper presents the results of a study of the effect of energy conditions (additional heating of the walls of the reaction chamber and subsequent action of an electron beam on the synthesized powder) of pulsed plasma-chemical synthesis on the morphology, average geometric size, phase and chemical composition of copper-containing silica-based nanocomposites. The nanocomposites were synthesized using a TEA-500 pulsed electron accelerator. It was the first time that copper-containing silica-based nanocomposites had been prepared using the pulsed plasma-chemical synthesis. The values of the band gap for the as-prepared nanocomposites were calculated. The nanocomposites were characterized by means of transmission electron microscopy and X-ray diffraction. The analysis revealed the changes in the morphology and phase composition of the nanocomposites upon energy conditions.
Effect of Conversion on Chain Addition Copolymerizations Performed in a Backmixed Drag Flow Extruder Reactor
Authors: Grenci J. , Todd D. B. 
Published: February 2022

Abstract
The use of a drag flow device such as a twin screw extruder for polymerization and/or copolymerization processes has been studied extensively over the years. Due to the high viscosities (100 to 100 000 poise) that are produced, poor backmixing is experienced in these drag flow devices. As a result, these studies have shown the extruder reactor to exhibit a ‘‘plug flow’’ behavior. A drag flow device has been developed that achieves good backmixing with high viscosity materials. This device incorporates two counter-rotating, nonintermeshing, screws; one screw conveying material forward, while the other conveying material backward.
Theory suggests that in a plug flow reactor the copolymer composition varies (drifts) as a function of time (position) in the reactor in most cases. Conversely in a micromixed continuous stirred tank reactor (CSTR) the copolymer produced does not drift as a function with position in the reactor. It has also been shown that this drift in copolymer composition becomes more pronounced at higher conversion. Experiments were performed in a counter-rotating nonintermeshing twin screw extruder using the ‘‘backmixed’’ configuration and a ‘‘conventional’’ configuration. Two copolymer systems were investigated; butyl acrylate/styrene and butyl acrylate/butyl methacrylate. The copolymerizations were conducted at three residence times for each system and configuration to provide materials of a wide variety of conversions (13 to 97 %). Monomer samples were taken at two ports in the extruder and at the die. Samples were analyzed for composition by two methods; FTIR and refractive index (RI).
It was shown that the copolymer composition of samples produced in the backmixed extruder reactor does not change significantly as a function of position in the reactor. This is an indication that the copolymer composition does not drift in the reactor. Theoretically this is the behavior that exists with a chain addition copolymerization that occurs in a CSTR. Two methods (RI, FTIR) were used in the copolymer formulation (BA/Sty) and one method (FTIR) was used in the other copolymer formulation (BA/BMA). It was further shown that the difference in copolymer compositions in the two extruder reactors is more pronounced at higher conversions than at lower conversions.
Numerical Simulation of Compression Molding of UHMWPE
Authors: Parasnis N. C. , Ramani K. 
Published: February 2022

Abstract
In part I of this paper a thermal model was used for temperature predictions within a compression molded disc. A process simulated laminate technique was used to measure residual stresses. The fast cooling cycle produced high residual stresses (∼10 MPa). The slow cooling cycle produced low residual stresses (∼1 MPa). The cycle with soak at crystallization also produced low residual stresses (∼2.6 MPa). The modeled and measured values were in close agreement. A major portion of the residual stresses (∼70 %) was developed within a short time period (∼10 min) after the end of crystallization for all the cycles.
Process parameter optimization for Fused Filament Fabrication additive manufacturing of PLA/PHA biodegradable polymer blend
Authors: Mustafa Muhammad Salman , Muneer Muhammad Arslan , Zafar Muhammad Qasim , Arif Muhammad , Hussain Ghulam , Siddiqui Farrukh Arsalan 
Published: February 2022

Abstract
Fused Filament Fabrication (FFF) is a widely embraced material extrusion (MEX) additive manufacturing (AM) process to produce complex three-dimensional structures, and it is typically used in the fabrication of biodegradable polymers for biomedical applications. However, FFF as a fabrication process for blended polymeric materials needs to be optimized for enhanced mechanical properties. In this work, biodegradable polylactic acid (PLA)/polyhydroxyalkanoate (PHA) dog-bone and notched specimens are printed to determine optimum printing parameters for superior mechanical properties in FFF additive manufacturing. The effect of layer thickness, infill density, and printing bed temperature on mechanical properties is investigated by employing a design of experiments (DoE) approach using response surface methodology (RSM). Experimental results showed the significance of the opted parameters for mechanical properties of the PLA/PHA blend. Then, optimum values for layer thickness, infill density, and printing bed temperature are identified for tensile and impact strength and an empirical relationship between parameters is formulated for low density and cost-effective fabrication. Finally, the analysis of variance (ANOVA) is performed to check the adequacy of the model for the influence of process parameters and their mutual interactions. The verification experiments validated the adequacy of the proposed model for PLA/PHA blend in FFF additive manufacturing.
Understanding softening of amorphous materials for FFF applications
Authors: Colón Quintana José Luis , Osswald Tim 
Published: February 2022

Abstract
The work explores the fundamentals of the softening process for amorphous materials expanding on the work presented by Stammers and Beek (Stammers, E. and Beek, W.J. (1969). The melting of a polymer on a hot surface. Polym. Eng. Sci. 9). The pressure induced melt removal process was studied in detail. The process, although fundamental, allows for an understanding of the phase transition of materials during the fused filament fabrication (FFF) process. Experimental results were analyzed using state-of-the-art equipment. A total of four materials were tested. PVC and PC are amorphous materials, and PA6 and PP are semi-crystalline materials. A setup was built to allow the application of a constant force. The resulting melt film was analyzed using computed tomography technology. The experimental results were compared with numerical simulation results originating from COMSOL Multiphysics and the analytical solution derived by Stammers and Beek. Rheological and thermo-mechanical tests were used to find the softening temperature of amorphous materials. Results showed a straightforward transition for the melting temperature of semi-crystalline materials and softening temperature of amorphous materials. It is suggested that for amorphous materials, the glass transition temperature can be used as the softening temperature (T

s
= T

g
). When comparing all three results (experimental, analytical, and numerical), values are within the same range and magnitude. A good approximation was achieved for PA6 and PVC, which have semi-crystalline and amorphous structures, respectively. Results provide insights into the phase transition process and phase change mechanisms during the extrusion of materials in the fused filament fabrication process.
Tensile, rheological and morphological characterizations of multi-walled carbon nanotube/polypropylene composites prepared by microinjection and compression molding
Authors: Ezat Gulstan S. , Kelly Adrian L. , Youseffi Mansour , Coates Phil D. 
Published: February 2022

Abstract
Polypropylene (PP) reinforced with 2 and 4 wt% of multi-walled carbon nanotubes (MWNT) were melt-blended in twin screw extruder and then molded by compression or micromolding process. The impact of injection speed on the surface morphology, rheological and tensile characteristics was investigated by using a scanning electron microscope, parallel plate rheometry, and tensiometry. Results showed that the tensile properties of micro-molded specimens were remarkably higher than those of the compression molded sheets. Compared to compression molded sheets, micromolded specimens demonstrated up to 40 and 244% higher tensile stiffness and yield strength, respectively, most likely due to the alignment of polymer chain segments in the flow direction induced during the micromolding process. It was observed that the fast filling speed caused a drop in the tensile properties of the nanocomposites and polymer. Rheological examination revealed that the presence of a rheological percolation network in the nanocomposites produced by micromolding and the fast injection speed was beneficial for establishing the percolated network. Morphological examination revealed that the size of nanotube agglomerations that appeared in micromolded specimens was up to five times smaller than in compression molded sheets and the agglomeration size decreased with the increase of the injection speed.
Antifouling improvement of a polyacrylonitrile membrane blended with an amphiphilic copolymer
Authors: Hu Jianlong , He Yingfang , Liu Peng , Shen Xiang 
Published: February 2022

Abstract
The amphiphilic copolymer polyacrylonitrile-co-poly(hydroxyethyl methacrylate) (PAN-co-PHEMA) was readily blended with polyacrylonitrile (PAN) to fabricate a flat-sheet blending membrane through non-solvent induced phase separation (NIPS). In the membrane-forming process, the hydrophilic PHEMA chains are uniformly distributed on the surface, as revealed by the energy-dispersive X-ray tests. The sponge-like sub-layer embedded with droplet-shaped structures is formed at the cross-sections of membranes, because of the high viscosity of the casting solution. With the increase of copolymer concentration, the mean pore size of the blending membranes increases from 26.9 to 99.8 nm, leading to the increase of membrane flux from 93.6 to 205.4 l/(m2h). The incorporation of PAN-co-PHEMA copolymer endows the blending membrane with a rough surface microstructure and enhanced hydrophilicity. The rejection ratio of membranes for emulsified pump oil reaches 99.9%, indicating a prominent separation performance. In the cycle permeation experiments, the flux recovery ratio of the blending membranes is as high as 99.6%, which is much higher than those of PAN membrane. The irreversible fouling of blending membranes induced by oil adsorption is alleviated, and converted into reversible fouling, owing to the reduction of the adhesion force between foulant and membrane surface. These results suggest that the anti-fouling property of PAN membranes has been dramatically strengthened via the addition of PAN-co-PHEMA copolymer.
Virtual and universal braid groups, their quotients and representations
Authors: Bardakov Valeriy , Emel’yanenkov Ivan , Ivanov Maxim , Kozlovskaya Tatyana , Nasybullov Timur , Vesnin Andrei 
Published: February 2022

Abstract
In the present paper, we study structural aspects of certain quotients of braid groups and virtual braid groups.
In particular, we construct and study linear representations

B
n

→

GL

n
⁢

(

n
-
1

)

/
2

⁢

(

Z
⁢

[

t

±
1

]

)

B_{n}\to\mathrm{GL}_{n(n-1)/2}(\mathbb{Z}[t^{\pm 1}])

,

VB
n

→

GL

n
⁢

(

n
-
1

)

/
2

⁢

(

Z
⁢

[

t

±
1

,

t
1

±
1

,

t
2

±
1

,
…
,

t

n
-
1

±
1

]

)

\mathrm{VB}_{n}\to\mathrm{GL}_{n(n-1)/2}(\mathbb{Z}[t^{\pm 1},t_{1}^{\pm 1},t_{2}^{\pm 1},\ldots,t_{n-1}^{\pm 1}])

which are connected with the famous Lawrence–Bigelow–Krammer representation.
It turns out that these representations induce faithful representations of the crystallographic groups

B
n

/

P
n
′

B_{n}/P_{n}^{\prime}

,

VB
n

/

VP
n
′

\mathrm{VB}_{n}/\mathrm{VP}_{n}^{\prime}

, respectively.
Using these representations we study certain properties of the groups

B
n

/

P
n
′

B_{n}/P_{n}^{\prime}

,

VB
n

/

VP
n
′

\mathrm{VB}_{n}/\mathrm{VP}_{n}^{\prime}

.
Moreover, we construct new representations and decompositions of the universal braid groups

UB
n

\mathrm{UB}_{n}

.