bluuebunny/crossref_metadata_2025 huggingface dataset:
Spinal TNF-α impedes Fbxo45-dependent Munc13-1 ubiquitination to mediate neuropathic allodynia in rats
Authors: Hsieh Ming-Chun , Ho Yu-Cheng , Lai Cheng-Yuan , Chou Dylan , Chen Gin-Den , Lin Tzer-Bin , Peng Hsien-Yu
Published: July 2018

Presynaptic active zone proteins play a crucial role in regulating synaptic plasticity. Although the ubiquitin–proteasome system underlying the degradation of the presynaptic active zone protein is well established, the contribution of this machinery to regulating spinal plasticity during neuropathic pain development remains unclear. Here, using male Sprague Dawley rats, we demonstrated along with behavioral allodynia, neuropathic injury induced a marked elevation in the expression levels of an active zone protein Munc13-1 in the homogenate and synaptic plasma membrane of the ipsilateral dorsal horn. Moreover, nerve injury-increased Munc13-1 expression was associated with an increase in the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs) in ipsilateral dorsal horn neurons. This neuropathic injury-induced accumulation of Munc13-1 colocalized with synaptophysin but not homer1 in the dorsal horn. Focal knockdown of spinal Munc13-1 expression attenuated behavioral allodynia and the increased frequency, not the amplitude, of mEPSCs in neuropathic rats. Remarkably, neuropathic injury decreased spinal Fbxo45 expression, Fbxo45-Munc13-1 co-precipitation, and Munc13-1 ubiquitination in the ipsilateral dorsal horn. Conversely, focal knockdown of spinal Fbxo45 expression in naive animals resulted in behavioral allodynia in association with similar protein expression and ubiquitination in the dorsal horn as observed with neuropathic injury rats. Furthermore, both neuropathic insults and intrathecal injection of tumor necrosis factor-α (TNF-α) impeded spinal Fbxo45-dependent Munc13-1 ubiquitination, which was reversed by intrathecal TNF-α-neutralizing antibody. Our data revealed that spinal TNF-α impedes Fbxo45-dependent Munc13-1 ubiquitination that accumulates Munc13-1 in the presynaptic area and hence facilitates the synaptic excitability of nociceptive neurotransmission underlying neuropathic pain.
Overexpression of endophilin A1 exacerbates synaptic alterations in a mouse model of Alzheimer’s disease
Authors: Yu Qing , Wang Yongfu , Du Fang , Yan Shijun , Hu Gang , Origlia Nicola , Rutigliano Grazia , Sun Qinru , Yu Haiyang , Ainge James , Yan Shi Fang , Gunn-Moore Frank , Yan Shirley ShiDu
Published: July 2018

Endophilin A1 (EP) is a protein enriched in synaptic terminals that has been linked to Alzheimer’s disease (AD). Previous in vitro studies have shown that EP can bind to a variety of proteins, which elicit changes in synaptic transmission of neurotransmitters and spine formation. Additionally, we previously showed that EP protein levels are elevated in AD patients and AD transgenic animal models. Here, we establish the in vivo consequences of upregulation of EP expression in amyloid-β peptide (Aβ)-rich environments, leading to changes in both long-term potentiation and learning and memory of transgenic animals. Specifically, increasing EP augmented cerebral Aβ accumulation. EP-mediated signal transduction via reactive oxygen species (ROS)/p38 mitogen-activated protein (MAP) kinase contributes to Aβ-induced mitochondrial dysfunction, synaptic injury, and cognitive decline, which could be rescued by blocking either ROS or p38 MAP kinase activity.
Statistical mechanics for metabolic networks during steady state growth
Authors: De Martino Daniele , MC Andersson Anna , Bergmiller Tobias , Guet Călin C. , Tkačik Gašper
Published: July 2018

Which properties of metabolic networks can be derived solely from stoichiometry? Predictive results have been obtained by flux balance analysis (FBA), by postulating that cells set metabolic fluxes to maximize growth rate. Here we consider a generalization of FBA to single-cell level using maximum entropy modeling, which we extend and test experimentally. Specifically, we define for Escherichia coli metabolism a flux distribution that yields the experimental growth rate: the model, containing FBA as a limit, provides a better match to measured fluxes and it makes a wide range of predictions: on flux variability, regulation, and correlations; on the relative importance of stoichiometry vs. optimization; on scaling relations for growth rate distributions. We validate the latter here with single-cell data at different sub-inhibitory antibiotic concentrations. The model quantifies growth optimization as emerging from the interplay of competitive dynamics in the population and regulation of metabolism at the level of single cells.
Asymmetric migration decreases stability but increases resilience in a heterogeneous metapopulation
Authors: Limdi Anurag , Pérez-Escudero Alfonso , Li Aming , Gore Jeff
Published: July 2018

Many natural populations are spatially distributed, forming a network of subpopulations linked by migration. Migration patterns are often asymmetric and heterogeneous, with important consequences on the ecology and evolution of the species. Here we investigate experimentally how asymmetric migration and heterogeneous structure affect a simple metapopulation of budding yeast, formed by one strain that produces a public good and a non-producer strain that benefits from it. We study metapopulations with star topology and asymmetric migration, finding that all their subpopulations have a higher fraction of producers than isolated populations. Furthermore, the metapopulations have lower tolerance to challenging environments but higher resilience to transient perturbations. This apparent paradox occurs because tolerance to a constant challenge depends on the weakest subpopulations of the network, while resilience to a transient perturbation depends on the strongest ones.
A critical view on transgenerational epigenetic inheritance in humans
Authors: Horsthemke Bernhard
Published: July 2018

Transgenerational epigenetic inheritance refers to the transmission of epigenetic information through the germline. While it has been observed in plants, nematodes and fruit flies, its occurrence in mammals—and humans in particular—is the matter of controversial debate, mostly because the study of transgenerational epigenetic inheritance is confounded by genetic, ecological and cultural inheritance. In this comment, I discuss the phenomenon of transgenerational epigenetic inheritance and the difficulty of providing conclusive proof for it in experimental and observational studies.
Proteasome-targeted nanobodies alleviate pathology and functional decline in an α-synuclein-based Parkinson’s disease model
Authors: Chatterjee Diptaman , Bhatt Mansi , Butler David , De Genst Erwin , Dobson Christopher M. , Messer Anne , Kordower Jeffrey H.
Published: July 2018

Therapeutics designed to target α-synuclein (α-syn) aggregation may be critical in halting the progression of pathology in Parkinson’s disease (PD) patients. Nanobodies are single-domain antibody fragments that bind with antibody specificity, but allow readier genetic engineering and delivery. When expressed intracellularly as intrabodies, anti-α-syn nanobodies fused to a proteasome-targeting proline, aspartate or glutamate, serine, and threonine (PEST) motif can modulate monomeric concentrations of target proteins. Here we aimed to validate and compare the in vivo therapeutic potential of gene therapy delivery of two proteasome-directed nanobodies selectively targeting α-syn in a synuclein overexpression-based PD model: VH14*PEST (non-amyloid component region) and NbSyn87*PEST (C-terminal region). Stereotaxic injections of adeno-associated viral 5-α-syn (AAV5-α-syn) into the substantia nigra (SN) were performed in Sprague–Dawley rats that were sorted into three cohorts based on pre-operative behavioral testing. Rats were treated with unilateral SN injections of vectors for VH14*PEST, NbSyn87*PEST, or injected with saline 3 weeks post lesion. Post-mortem assessments of the SN showed that both nanobodies markedly reduced the level of phosphorylated Serine-129 α-syn labeling relative to saline-treated animals. VH14*PEST showed considerable maintenance of striatal dopaminergic tone in comparison to saline-treated and NbSyn87*PEST-treated animals as measured by tyrosine hydroxylase immunoreactivity (optical density), DAT immunoreactivity (optical density), and dopamine concentration (high-performance liquid chromatography). Microglial accumulation and inflammatory response, assessed by stereological counts of Iba-1-labeled cells, was modestly increased in NbSyn87*PEST-injected rats but not in VH14*PEST-treated or saline-treated animals. Modest behavioral rescue was also observed, although there was pronounced variability among individual animals. These data validate in vivo therapeutic efficacy of vector-delivered intracellular nanobodies targeting α-syn misfolding and aggregation in synucleinopathies such as PD.
Author Correction: Nitrogen-fixing populations of Planctomycetes and Proteobacteria are abundant in surface ocean metagenomes
Authors: Delmont Tom O. , Quince Christopher , Shaiber Alon , Esen Özcan C. , Lee Sonny TM , Rappé Michael S. , McLellan Sandra L. , Lücker Sebastian , Eren A. Murat
Published: July 2018

In the version of this Article originally published, the surname of author Sandra M. McLellan was spelt incorrectly as ‘MacLellan’. This has now been corrected. In addition, Fig. 2 was mistakenly duplicated in the Supplementary Information as Supplementary Fig. 2. This has now been replaced with the correct supplementary figure (shown below).
Use of phosphate-binders and risk of infection-related and all-cause mortality in patients undergoing hemodialysis: The Q-Cohort Study
Authors: Yamada Shunsuke , Tokumoto Masanori , Taniguchi Masatomo , Yoshida Hisako , Arase Hokuto , Tatsumoto Narihito , Hirakata Hideki , Kitazono Takanari , Tsuruya Kazuhiko
Published: July 2018

The use of phosphate (P)-binders allows hemodialysis patients to take in more protein and thus may maintain a good nutritional status. Protein-energy-malnutrition increases the risk of infection-related death. The association between use of P-binders and the relative risks of infection-related death remains unknown in hemodialysis patients. A total of 2926 hemodialysis patients registered to the Q-Cohort Study was followed up for 4-years. The association between use of P-binders and the risks for infection-related and all-cause mortality were estimated by Cox proportional hazards risk model with multiple adjustments by conventional and propensity-score based approaches. During the follow-up period, 106 patients and 492 patients died of infection and any cause, respectively. Cox proportional hazards models with multivariable adjustments including nutritional confounders showed that the incidence of infection-related death was significantly lower in patients with P-binders use compared with those without (hazard ratio [95% confidence interval] for infection-related mortality 0.63 [0.40–0.99]). The results remained significant even after applying four different propensity score-based analyses. Notably, use of P-binders was associated with a lower risk of all-cause mortality. Further studies including randomized controlled clinical trials and observational studies analyzed by an instrumental variable model will provide more robust evidences for the associations observed in our study.
Erratum: Fish and fishery historical data since the 19th century in the Adriatic Sea, Mediterranean
Authors: Fortibuoni Tomaso , Libralato Simone , Arneri Enrico , Giovanardi Otello , Solidoro Cosimo , Raicevich Saša
Published: July 2018

Scientific Data 4:170104 doi: 10.1038/sdata.2017.104 (2017), Published 12 September 2017; Updated 24 July 2018 In the HTML version of this Data Descriptor, Data Citation 8 incorrectly listed the repository as VLIZ instead of EMODnet Bathymetry.
Selection analyses of paired HIV-1 gag and gp41 sequences obtained before and after antiretroviral therapy
Authors: Tzou Philip L. , Rhee Soo-Yon , Pond Sergei L. Kosakovsky , Manasa Justen , Shafer Robert W.
Published: July 2018

Most HIV-1-infected individuals with virological failure on a pharmacologically-boosted protease inhibitor (PI) regimen do not develop PI-resistance protease mutations. One proposed explanation is that HIV-1 gag or gp41 cytoplasmic domain mutations might also reduce PI susceptibility. In a recent study of paired gag and gp41 sequences from individuals with virological failure on a PI regimen, we did not identify PI-selected mutations and concluded that if such mutations existed, larger numbers of paired sequences from multiple studies would be needed for their identification. In this study, we generated site-specific amino acid profiles using gag and gp41 published sequences from 5,338 and 4,242 ART-naïve individuals, respectively, to assist researchers identify unusual mutations arising during therapy and to provide scripts for performing established and novel maximal likelihood estimates of dN/dS substitution rates in paired sequences. The pipelines used to generate the curated sequences, amino acid profiles, and dN/dS analyses will facilitate the application of consistent methods to paired gag and gp41 sequence datasets and expedite the identification of potential sites under PI-selection pressure.
A fluorescent sensor based on aggregation-induced emission: highly sensitive detection of hydrazine and its application in living cell imaging
Authors: Qiu Jiabin , Chen Yunxiang , Jiang Shengjie , Guo Hongyu , Yang Fafu
Published: July 2018

A fluorescent sensor based on aggregation-induced emission for amines was prepared and its highly sensitive detection of hydrazine and application in living cell imaging were investigated in detail.
A facile and sensitive tetrabromobisphenol-A sensor based on biomimetic catalysis of a metal–organic framework: PCN-222(Fe)
Authors: Yu Guangxia , Song Xin , Zheng Shijie , Zhao Qiang , Yan Danting , Zhao Jinshun
Published: July 2018

A facile electrode based on a metal–organic framework (PCN-222(Fe)) and acetylene black was fabricated for sensitive detection of tetrabromobisphenol-A (TBBPA).
Chiral phosphoric acid-catalyzed direct asymmetric mannich reaction of cyclicC-acylimines with simple ketones: facile access to C2-quaternary indolin-3-ones
Authors: Li Jin-Shan , Liu Yong-Jie , Li Shen , Ma Jun-An
Published: July 2018

A chiral Brønsted acid-catalyzed direct asymmetric Mannich reaction of simple ketones with cyclicC-acylimines has been established for the synthesis of C2-quaternary indolin-3-ones.
Biocompatible MOFs with high absolute quantum yield for bioimaging in the second near infrared window
Authors: Sava Gallis Dorina F. , Butler Kimberly S. , Rohwer Lauren E. S. , McBride Amber A. , Vincent Grace , Chong Casey V. , Pearce Charles J. , Luk Ting S.
Published: July 2018

Biocompatible mixed metal YbNd metal–organic frameworks are demonstrated to be highly efficient emitters in the second NIR window.
Aqueous sodium hydroxide (NaOH) solutions at high pressure and temperature: insights fromin situRaman spectroscopy andab initiomolecular dynamics simulations
Authors: Stefanski Johannes , Schmidt Christian , Jahn Sandro
Published: July 2018

Hydrothermal diamond anvil cell experiments in combination with Raman spectroscopy and first principles molecular dynamics simulations were performed to investigate the structure and dynamics of aqueous NaOH solutions for temperatures up to 700 °C and pressures up to 850 MPa.
Single-molecule fluorescence enhancement of a near-infrared dye by gold nanorods using DNA transient binding
Authors: Zhang Weichun , Caldarola Martín , Lu Xuxing , Pradhan Biswajit , Orrit Michel
Published: July 2018

Fluorescence enhancement by plasmonic nanostructures enables the optical detection of single molecules with weak fluorescence, extending the scope of molecular fluorescence imaging to new materials and systems.
Large-scale QM/MM free energy simulations of enzyme catalysis reveal the influence of charge transfer
Authors: Kulik Heather J.
Published: July 2018

Large-scale QM/MM free energy simulations reveal long-range fluctuations in charges on residues in enzyme active sites during dynamics.
Uranium adsorption from sulfuric acid media using silica materials functionalised with amide and phosphorous ligands
Authors: Le Nedelec Tom , Charlot Alexandre , Calard François , Cuer Frédéric , Leydier Antoine , Grandjean Agnès
Published: July 2018

Identification of functional groups grafted onto silica supports to provide a promising uranium extraction capacity and a high selectivity versus iron.
Controlled design of PtPd nanodendrite ornamented niobium oxynitride nanosheets for solar-driven water splitting
Authors: Ahmad Yahia H. , Eid Kamel , Mahmoud Khaled A. , Al-Qaradawi Siham Y.
Published: July 2018

A facile road-map is developed for one-pot synthesis of PtPd nanodendrite ornamented niobium oxynitride nanosheets for efficient solar-driven water splitting.
Metal–organic framework-templated synthesis of sulfur-doped core–sheath nanoarrays and nanoporous carbon for flexible all-solid-state asymmetric supercapacitors
Authors: Dai Simeng , Yuan Yan , Yu Jiangsheng , Tang Jian , Zhou Jie , Tang Weihua
Published: July 2018

MOFs are adopted for facile synthesizing hierarchical hollow architectures for energy storage.
Renewable polyols for advanced polyurethane foams from diverse biomass resources
Authors: Furtwengler Pierre , Avérous Luc
Published: July 2018

This review highlights recent advances in the synthesis of renewable polyols, used for making polyurethane foams, from biomass.
Correction: The intramolecular hydrogen bonded–halogen bond: a new strategy for preorganization and enhanced binding
Authors: Riel Asia Marie S. , Decato Daniel A. , Sun Jiyu , Massena Casey J. , Jessop Morly J. , Berryman Orion B.
Published: July 2018

Correction for ‘The intramolecular hydrogen bonded–halogen bond: a new strategy for preorganization and enhanced binding’ by Asia Marie S. Riel et al., Chem. Sci., 2018, 9, 5828–5836.
Theoretical considerations concerning the profile error of the thread flank
Authors: Slătineanu Laurenţiu , Dodun Oana , Beşliu Băncescu Irina , Coman Ionel , Ghionea Adrian , Mihordea Traian
Published: July 2018

In the case of metric thread, a possible source of the flank error could be the position of the cutting tool edge, which could not intersect the circular cylindrical surface axis. An analytical method of approximation was applied to model the way in which the flank error is generated by considering some geometrical conditions. A theoretical simplified model was determined to highlight the influence of the thread external diameter and of the distance between the circular cylindrical surface axis and the thread rectilinear generatrix on the profile error of thread flank.
Features of synthesis method of functionoriented technologies for the ship units details
Authors: Kоstenko Аndrey , Mikhaylov Аleksandr
Published: July 2018

Function-oriented technologies are one of the ways of the problem solving facing modern engineering to improve the quality of details. The general method consists of ten transitions having iterative relationship with each other.
Researches regarding introducing temperature as a factor in cutting tool wear monitoring
Authors: Inţă Marinela , Muntean Achim
Published: July 2018

Monitoring the tool state during the cutting process becomes very important since the introduction of CAM in manufacturing process. The tool life based only on economic data is not enough especially in the case precision cutting due to the scattering of tool wear which depends on much more mechanical and physical properties of the workpiece and tool materials. Attempts to assess the state of wear of the tool by direct measurement of the wear indicators have been unsuccessful due to difficult access in the cutting zone and measurement imprecision. We have so wear patterns appreciation by measuring indirect indicators of wear, the main models are based on measuring vibration, acoustic emission or cutting forces and power consumption separately or together. These models have the disadvantage that should be followed at least two indicators simultaneously for a minimum precision of the results. Considering the wear models developed over time it can be seen that there is a clear relationship between wear and stabilized temperature. The paper aims to study the introduction temperature as indirect indicator of tool state in addition to the existing indicators, this leads to increased reliability of results of monitoring of wear.
The influence of brushing on the surface quality of aluminium
Authors: Teicher Uwe , Schulze Richard , Brosius Alexander , Nestler Andreas
Published: July 2018

The extension of technical capabilities of machine centres for complete machining of components can improve their performance. In the field of sheet metal machining, the objective beside the classic milling operation was a generation of functional surfaces by face brushing. The experimental studies have probed the influence of tools and technological parameters on the surface quality. In addition to an analysis of the relevant roughness parameters the formation of the surface topography was analysed by several measurement methods. By the application of force measurement, the results of the surface quality can be interpreted additionally. It could be shown that the feed rate in contrast to the cutting speed has the main influence on the surface roughness. A peculiarity is given by the parameter-based width of cut that should be known for reliable process control. The acquired data can be applied in the form of process characteristic fields for further processing with simulation and modelling methods.
Optimizing ANN performance using DOE: application on turning of a titanium alloy
Authors: Kechagias John , Tsiolikas Aristidis , Asteris Panagiotis , Vaxevanidis Nikolaos
Published: July 2018

A methodology is presented to optimize the performance of an Artificial Neural Network (ANN) using Design of Experiments (DOE). 8 different feed forward back propagation (FFBP) ANNs were developed and tested according to the L8 full factorial orthogonal array. The 3 parameters tested were: Number of Hidden Neurons, Learning rate, and Momentum; each one having two levels. By utilizing the analysis of means (ANOM) and the analysis of variances (ANOVA), the optimum levels of ANN parameters were determined. The developed ANN was applied for predicting cutting forces and average surface roughness in turning Ti-6Al-4V alloy.
Simple equipment for studying the injection molding process
Authors: Hriţuc Adelina
Published: July 2018

The injection molding process is largely applied to obtain plastic parts. The problem of finding a simple equipment able to allow the study of the injection process was addressed in the research presented in this paper. Aiming to solve the problem, the main requests valid for the proposed equipment were formulated. Considering some possible versions of the equipment subassemblies, the ideas diagram method and the method of imposed decision were applied to select the most convenient version of the injection equipment. As a result, a constructive solution for a simple injection molding equipment that could be used to develop some experimental researches was identified.
Geometrical analysis, for rapid prototyping, of the compressor’s helical conic rotor model
Authors: Baroiu Nicuşor , Păunoiu Viorel , Teodor Virgil Gabriel , Susac Florin , Oancea Nicolae
Published: July 2018

The conical rotary compressor represents a solution for gases compression, for relatively small flow, in conditions of a superior energetic efficiency. Although the theoretical solution for the helical conical compressor was elaborated decades ago, a viable technology solution become possible at industrial level only after the development of machine tools with numerically controlled axes. In this paper is proposed a study, analytical and graphical, concerning the geometry of conical rotary compressor’s rotors, modelled by rapid prototyping technology. The propose modelling allow to elaborate various constructive forms for conical compressor’s rotors.
Analysis of the influence of position of welding materials on the FSW seams properties for three dissimilar aluminium alloy
Authors: Bosneag Ana , Constantin Marius Adrian , Niţu Eduard , Iordache Monica
Published: July 2018

Friction Stir Welding, abbreviated FSW is a new and innovative welding process. This welding process is increasingly required, more than traditional arc welding, in industrial environment such us: aeronautics, shipbuilding, aerospace, automotive, railways, general fabrication, nuclear, military, robotics and computers. FSW, more than traditional arc welding, have a lot of advantages, such us the following: it uses a non-consumable tool, realise the welding process without melting the workpiece material, can be realised in all positions (no weld pool), results of good mechanical properties, can use dissimilar materials and have a low environmental impact. This paper presents the results of experimental investigation of friction stir welding joints to three dissimilar aluminium alloy AA2024, AA6061 and AA7075. For experimenting the value of the input process parameters, the rotation speed and advancing speed were kept the same and the position of plates was variable. The exit date recorded in the time of process and after this, will be compared between them and the influence of position of plate will be identified on the welding seams properties and the best position of plates for this process parameters and materials.
Direct metallization by a plasma coating process on thermal conductive polyamide
Authors: Sover Alexandru , Amend Jonas
Published: July 2018

This paper describes the metallization on highly filled thermal conductive Polyamide 6 material and the influence of the process conditions of the samples on the quality of the metal deposition. In a series of tests it is establish that the quality of the injection moulding process and fillers used for the polyamide material has a significant impact on the metal deposition on the polymeric surface. Even if the same surface roughness is generated by laser structuring the adhesion of the metallic particles decreases considerably as the quality of the polymeric surface is less perfect, i.e. when more fillers appear on the surface of the sample.
Characterisation of porous coatings formed on titanium under DC plasma electrolytic oxidation
Authors: Rokosz Krzysztof , Hryniewicz Tadeusz , Gaiaschi Sofia , Chapon Patrick , Raaen Steinar , Dudek Łukasz , Pietrzak Kornel , Malorny Winfried , Ciuperca Radion
Published: July 2018

Porous coatings on titanium may be obtained by AC or DC Plasma Electrolytic Oxidation (PEO) process. One has to point out that depending on the plasma treatment the ranges of voltages used are different. It has been found that for DC PEO processing the voltage must be higher than that in the case of AC PEO treatment. In addition, the shape and frequency of the voltage signal have also an impact. Produced coatings were examined with scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and glow discharge optical emission spectroscopy (GDEOS). It was found that it is possible to obtain the porous coatings enriched with phosphorus and copper by use of DC-PEO at 500, 575 and 650 VDC, whereas increasing the PEO voltage results in an increase of Cu/P (copper-to-phosphorus) atomic ratio. Furthermore, based on GDEOS data, three sublayers with different elements concentrations were detected ranging as follows 0-350, 350-2100, 2100-2900 seconds of sputtering time for 575 VDC. Based on XPS results the top 10 nm layer, consisted mainly of titanium (Ti4+), copper (Cu+ and/or Cu2+), and phosphates (PO43–, HPO42–, H2PO4–, P2O73–).
Effect of novolac nanoparticles additions on specific gravity of NBR/CR blends
Authors: Al-Maamori Mohammed H. , Al-Mosawi Ali I. , Abbas Abdulsada Shaymaa
Published: July 2018

In this article, novolac nanoparticles with different weight fraction (0-40) wt.% were added to NBR/CR blends and investigate the effect of these additions on the specific gravity of rubber blend. The results obtained shown that the novolac nanoparticles works on increasing the specific gravity of NBR/CR blends, and specific gravity ratio increases with increased novolac nanoparticles percentage.
About buckling calculus of straight bars on elastic environment by Transfer-Matrix Method (TMM) for dental implants
Authors: Tripa Mihai , Şolea Geamilia , Sorcoi Dorina , Florescu Iulia , Sorcoi Adriana , Păunescu Daniela , Bâlc Nicolae , Suciu Mihaela
Published: July 2018

The paper presents a relatively simple and elegant analytical calculus of critical buckling force for a straight bar, one-end embedded and other end free, with an axial compression force F, using the Transfer-Matrix Method (TMM). The algorithm is based on the simplifications of the mathematical apparatus offered by Dirac and Heaviside’s functions and operators regarding effort density. The results obtained will be used in the study of dental implants. The implant was assimilated as a bar on elastic environment, one-end of bar embedded and other end free, with an axial compression force F at the free end, the bone being assimilated as an elastic environment.
Configuring a system for hydraulic oil contamination management
Authors: Dusa Petru , Purice Eugen , Lupascu Radu , Ripanu Iustina , Fandarac Gabriel
Published: July 2018

Through contamination, we can understand anything foreign to a hydraulic system. In this paper we only refer to particle contamination. Analyzing and optimizing processes with regard to component cleanliness and fluid purity is the target of contamination management. The paper proposes a conceptual installation solution for the use of particle counters in order to optimize the measurement process. There is also a way of using the facility within a contamination management system.
Considerations on determining the castability of dental casting alloys
Authors: Deac Cristian , Gligor Alina , Tarnu Lucian
Published: July 2018

Castability is, along with biocompatibility, one of the most important characteristics of metallic materials used for dental prosthetic applications. In addition, the characteristics and performance of the employed casting machine are also decisive for the end result of the casting, especially when dealing with titanium or a titanium alloy. Starting from a critical analysis of the existing methods for determining the castability of dental alloys, the current paper presents a new method (and associated pattern) for determining the castability. Also, given the castability’s dependence on the type of casting machine, the paper includes an analysis of suitable casting machines and suggests some possible improvements.
Study of structural changes in metallic materials subjected to shock stress
Authors: Cristea Sorin , Bibu Marius
Published: July 2018

Behavior analysis of materials subjected to extreme demands remains a topical field for a wide range of engineering applications. The materials in discussion are in increasing numbers composites or layered materials, but homogeneous materials are not neglected either. The paper addresses the topic of a homogeneous metallic material subjected to shock loads. Two different thicknesses of alloy steel of known composition were used. Thicknesses used were of 4 mm and 6 mm respectively. After the loads were applied, the samples were cut in the direction of planes passing through the impact point; the microdurity was measured in the crosssection obtained and the medium microdurity areas were plotted. The obtained results allowed the identification of particularities in material behavior, in relation with the thickness, for the same values of the shock energy load and same shape of the penetrator.
An environmental friendly model for materials substitution in a fiberglass reinforced polyester composite
Authors: Axinte Eugen , Wang Yan , Abdul-Rani Ahmad Majdi , Abdu Aliyu Abdul Azeez , Andronic Octavian , Stegaru Ciprian , Bofu Andrei
Published: July 2018

In this work is presented an empirical developed model for materials substitution: an empirical established quantity of a fiberglass reinforced polyester composite (basic material) was substituted successively with two natural cheaper materials (natural wastes) resulted from other manufacturing processes. The experiment is purely empirical and no theory is developed in this work. The main scope is to observe if the new and cheapest materials can successful replace the much expensive basic materials in some industrial applications. The microstructures and some physical and mechanical properties of the new materials were studied by reporting to the basic material.
Waves in electric contact wires subjected to transversal impulses
Authors: Oprea Răzvan Andrei , Popa Gabriel , Gheţi Marius Alin
Published: July 2018

It is a well-known fact that the raising of the pantograph is followed by an electric arch. The reasons for this phenomenon are the oscillations of the pantograph and the oscillations of the contact line. Initially, these oscillations are not coupled. In this case, the mechanical contact between the two subsystems may be lost, and may generate electric arch. In the present work, the pantograph rising is modelled through a Dirac impulse. An analytic solution of the transverse waves is obtained by means of Fourier series. A phenomenological model of the wave attenuation is taken into account.
An overview of possibilities for CAM machining
Authors: Mihalache Andrei Marius
Published: July 2018

There is an entire array of options when you are planning a CAM machining strategy. Knowing your equipment possibilities and adjusting your software options to them has become mandatory in terms of cost and time efficiency. This paper aims to present the main options for most common software solutions used today in modern mechanical engineering which can be applied to the existing hardware manufacturing equipment found in enterprises or educational centers.
The necessity of using high quality orthoses in rehabilitation medicine
Authors: Amaricai Elena
Published: July 2018

In rehabilitation medicine there is increasing need of using high quality orthoses that can provide either good stability of the joint or good correction of the postural defect. The advantages of using orthoses that are in the same time hypoallergenic, lightweight, flexible, resistant and durable over time should be considered when prescribing them in clinical practice. This study presents different types of orthoses and the necessity of proper selection of materials when choosing the best ones. We included 34 patients diagnosed with different musculoskeletal conditions (thoracic and thoraco-lumbar scoliosis, genu valgum deviation and rheumatoid arthritis) that required the use of special orthoses (thoraco-lumbar braces, knee or hand orthoses). Patients were asked to complete a questionnaire regarding the quality of the orthoses that they have been used. The following characteristics of an orthosis should be considered when choosing the right one: easily wearable, comfortable, offering good stability of a joint, high quality, lightweight, hypoallergenic and resistant.
Study regarding the structural response of standard cylindrical roller bearings using ANSYS and MESYS
Authors: Puşcaşu Alin Marian , Lupescu Octavian , Bădănac Ana
Published: July 2018

Bearings are manufactured in a wide variety of types and sizes especially with a single row of rollers, two rows of rollers or more, with cages or roller beside roller. Researches carried out by authors in this paper have followed a comparative analysis between a standard cylindrical roller bearings design and a prototype design using finite element method software's like ANSYS and MESYS. ANSYS is commonly used and enjoyed by an extended use in the structural areas, for analysis. ANSYS it consists of three main phases: Pre-processing, conducting or importing of the solid model system that are to be analyzed, solid meshing design in finite elements, implementation of conditions and loads at the limit, Processing, numeric solving of the characteristic equations behavior of the system and getting the solution, Post-processing, viewing the results in order to analyses system reaction and identification of areas with critical applications. The purpose of the study was to collect data's using two different software's and after to compare them with mathematical results. Using the ANSYS in this purpose it was able to analyses the design of the structure of the cylindrical roller bearing in detail.
Design and operating rules in the essential requirements – ergonomic aspects
Authors: Górny Adam
Published: July 2018

Technical equipment should satisfy safety specifications and ergonomic requirements throughout its usable life. The ergonomic requirements applied in the design process should be perceived as an integral part of the body of requirements intended to ensure the safest possible operation of technical equipment. Ergonomic criteria highlight the necessity to adjust technical equipment to the needs of users so as to avert any identified hazards. The design safety requirements defined as essential should also be seen as guidelines for the development of conditions which ensure the effective performance of work. Such requirements must account for ergonomic criteria, which need to be seen as a mandatory. The article refers to the need to take into account ergonomic requirements when designing machines and technical devices. Examples of such requirements and the possibility of verifying their implementation are indicated.
Contribution to predefinition of the geometric features and their processing sequences in order to create a CAPP model
Authors: Pişec Iaroslav Francisc , Blaga Florin Sandu
Published: July 2018

In order to create a Computer Aided Process Planning (CAPP) model for a family of parts, it is necessary to establish a database containing the geometric features specific to that family. In the car body production line industry, several families of parts can be determined each having specific geometric features. The parts that are part of a family of parts must be designed in such a way that at the end, they contain those specific features. The next step in the implementation of the CAPP model, is to create a database for processing sequences associated with geometric features. Combining these two databases, the database of geometric features and the processing sequences, the result is the NC program of the designed part. This study presents the creation of these two databases and the link between them.
Evaluation of the vertical vibrations behaviour of the bogie at failure of the dampers in the primary suspension of the railway vehicle
Authors: Dumitriu Mădălina , Gheţi Marius Alin
Published: July 2018

The paper aims to evaluate the behaviour of vertical vibrations of a two-axle bogie at failure of a damper in the primary suspension of the vehicle. The level of vibrations in the bogie is shown to rise as a consequence of the imbalance triggered in the system by the fault damper, resulting in dynamic interferences between the bounce and pitch vibrations of the bogie. This fact is highlighted by the results derived from the numerical simulations, which feature the frequency response functions of the bogie during rolling on a track with vertical irregularities. Various scenarios will be considered for lowering the damping constant in comparison with the reference value.
Influence of resistance to motion of railway vehicles on the longitudinal trains dynamics
Authors: Crăciun Camil , Cruceanu Cătălin
Published: July 2018

Longitudinal dynamics of trains is a subject that generates discussions and views on the parameters that interfere and influence both the size of the forces and their distribution in the train body. The paper is a study to determine the influence of resistances to motion on the longitudinal dynamic forces that develop in the body of the train in the braking process. For this, a train study model of ten identical vehicles, to which the locomotive may or may not be attached, is adopted. Initially, the simulation program for the non-locomotive model is run in two variants: with and without introducing additional resistances to motion, followed by the same simulations but with the locomotive introduced and a wagon removed, thus the number of vehicles remains the same for all the cases presented.
Failure modes analysis of railway wheel
Authors: Spiroiu Marius-Adrian , Nicolescu Mircea
Published: July 2018

In this paper are analysed the wheel failure modes, based on real field data, obtained during a period of a year of operation of freight wagons. The failure modes and their occurrence absolute frequencies are identified and a Pareto analysis is carried out. In the case of the four major failure modes a total time on test transform is performed and the failure probabilistic models are estimated, based on the Weibull distribution. The failure rates of the four failure modes are close to be constant, thus the behaviour of the railway wheel - in its normal life - is close to that of a non-ageing system. This conclusion is in line with the general theory regarding the behaviour of systems during their normal/useful life.
Construction of elastic wheels on light rail vehicles
Authors: Sebeşan Ioan , Arsene Sorin , Manea Ion
Published: July 2018

In the case of urban rail transport, light vehicles can be an effective solution due to the advantages offered by the elastic wheels. One of the great advantages of these rolling elements is given by the reduction of unsuspended masses of the vehicle which have the effect of reducing the vehicle-rolling interaction forces. However, there are no other advantages to be missed, such as noise reduction (very important for urban vehicles) and improved walking quality. This paper aims at presenting the construction and design elements of the elastic wheels. It is hoped to improve the quality of the urban transport vehicles in Romania. At the same time, dynamic effects will be analysed and presented on the wheel - rail contact, in the case of vehicles equipped with elastic wheels.
Dynamic model elaboration for the planetaryprecessional gear reducer against vibration
Authors: Dulgheru Valeriu , Malcoci Iulian
Published: July 2018

The purpose of modern-day machines in general and gear-box in particular is to carry out needs-based on maintenance, good working conditions and to minimize the repair and other servicing downtimes and disfunctionalities. This increases the overall equipment effectiveness and optimizes the cost. The mechanical condition of a machine or a machine components can be accurately diagnosed from the nature and extend of vibration they generate. The aim is to detect damage as it occurs, allowing scheduled repairs or maintenance to be carried out in time.
Theoretical basics and experimental methods of consideration of the concrete mixtures' movement resistance in the concrete-delivery pipelines
Authors: Novikov Sergey , Zhadanovsky Boris , Sinenko Sergey
Published: July 2018

The directions associated with development and improvement in the field of works' production using the concrete and reinforced concrete are related mainly with the improvement of the quality and durability of concrete and products based on it, the rational use of material and energy resources. The research points to the necessity of determination of the exploitative performance with considering the certain factors of influence on the construction technological processes wherein the factor related with abrasiveness and aggregates size has not been fully studied. The methodology for laboratory studies of the slip velocity of a concrete mixture in the concrete-delivery pipelines is proposed: theoretical methods for estimating the resistance to movement of concrete mixtures are determined. The method for determining the specific resistance to the movement of concrete mixtures using an installation that takes into account resistance to movement of abrasive mass has been developed. Thus, the developed methods of accounting the resistance to the movement of concrete mixtures in concrete-delivery pipelines make it possible to substantially save the cost of transporting the concrete mixture with the best exploitative performance.
Definition of the coefficient of blackness for inhomogeneous surfaces under conducting thermography
Authors: Kletska Olha , Falendysh Anatoliy , Vasylenko Oleh , Onyshchenko Andrii
Published: July 2018

The paper considers the possibility of determining the coefficient of blackness or the degree of radiation for inhomogeneous surfaces during thermography. Such approach will allow increasing the accuracy of the analysis of the level of qualitative heat losses during the energy audit of the facility. As a rule, when conducting an energy audit, reference values are used which are given only for one type of material, which introduces an additional error both in the measurement and in the processing of the material.In the majority of cases, thermography is carried out on inhomogeneous surfaces that have different physical characteristics and correspondingly different values of the blackness coefficient. The proposed dependence makes it possible to take into account the heterogeneity of the surface according to the type of material and their ratio to the overall surface of the object under study.The use of this approach will increase the accuracy of the study in thermography and, accordingly, the quality of processing of the thermograms obtained.
Direct measurements using on-board diagnostics: study of the dynamics of a vehicle equipped with a DSG automated transmission
Authors: Micu Dan , Fileru Iordan , Toma Marius , Andreescu Cristian
Published: July 2018

The paper aims to analyze a series of OBD data from a Volkswagen Passat 2.0 tdi, 103 kW, equipped with an automatic DSG transmission, while traveling in the city. Some parameters are analyzed, with a special emphasis on the relation between the engine speed and vehicle speed, presenting also an example of using the information provided by the OBD to determine the gear ratios. The gear steps and the way they are used while driving the vehicle are identified in the end.
Aerodynamic efficiency enhancement for asymmetric profiles
Authors: Bostan Viorel , Guţu Marin , Odainâi Valeriu
Published: July 2018

This paper presents a solution for enhancement of aerodynamic efficiency for asymmetric airfoils. In order to increase the lift and reduce the drag forces for a blade segment, a groove was created on its surface. There were carried out experiments consisting in the analysis of two asymmetric airfoil segments of the same type in the wind tunnel. One segment was designed with the groove and the other without it. The optimum location of the groove was determined by means of CFD analysis. Simulation results were compared to test results and the CFD analysis model was validated.
Method of axial adjustment for precessional transmissions
Authors: Bostan Ion , Mazuru Sergiu , Casian Maxim
Published: July 2018

Axial adjustment method for precessional transmissions includes compensation error calculation, determination compensator groups, achieved in the form of base and auxiliary rings. The compensator has on the base ring axial canals in which can be placed clamping bolts but the auxiliary ring has axial holes for the screws. The auxiliary ring is formed from increasing sectors - the distance between auxiliary ring stairs and front side of body, from decreasing sectors - the distance between base ring and bottom place, and the closure element - the clearance between gear body and the front surface of the base ring. According to the method of group interchangeability is determined the deviation value of the upper and lower group tolerance and the clearance between lid and body. Then rotating one of the rings is ensured the dimension of the compensator which must match to compensation clearance value and then the compensator is adjusted to required value.