Reabilitarea unei săli de sport dintr-un spaţiu de învăţământ

This paper present the faultsand demages detected at the bearing structure of the stairs as well as the necessary consolidation for reuse purposes

Kinked silicon nanowires-enabled interweaving electrode configuration for lithium-ion batteries

A tri-dimensional interweaving kinked silicon nanowires (k-SiNWs) assembly, with a Ni current collector co-integrated, is evaluated as electrode configuration for lithium ion batteries. The large-scale fabrication of k-SiNWs is based on a procedure for continuous metal assisted chemical etching of Si, supported by a chemical peeling step that enables the reuse of the Si substrate. The kinks are triggered by a simple, repetitive etch-quench sequence in a HF and H2O2-based etchant. We find that the inter-locking frameworks of k-SiNWs and multi-walled carbon nanotubes exhibit beneficial mechanical properties with a foam-like behavior amplified by the kinks and a suitable porosity for a minimal electrode deformation upon Li insertion. In addition, ionic liquid electrolyte systems associated with the integrated Ni current collector repress the detrimental effects related to the Si-Li alloying reaction, enabling high cycling stability with 80% capacity retention (1695 mAh/gSi) after 100 cycles. Areal capacities of 2.42 mAh/cm2 (1276 mAh/gelectrode) can be achieved at the maximum evaluated thickness (corresponding to 1.3 mgSi/cm2). This work emphasizes the versatility of the metal assisted chemical etching for the synthesis of advanced Si nanostructures for high performance lithium ion battery electrodes

Defixiones d'Istros

Κατάδεσμοι από την Ίστρο Οι συγγραφείς δημοσιεύουν οκτώ μολύβδινους καταδέσμους, που διατηρούνται αποσπασματικά, οι οποίοι ανακαλύφθηκαν τυχαία στη νεκρόπολη της Ίστρου και χρονολογούνται στον 4ο αι. π. Χ. Ο πρώτος κατάδεσμος είναι προφανώς ένας defixio iudiciaria, οι αριθμοί 2 έως 4 είναι λίστες ονομάτων (αναμφίβολα defixiones iudiciariae), οι αριθμοί 5 έως 7 είναι σχεδόν αδύνατο να αναγνωσθούν, ενώ ο αριθμός 8 είναι ένα ενεπίγραφο μολύβδινο κάλυμμα. Το σπουδαιότερο κείμενο είναι εκείνο του αριθμού 1. Το σχόλιο αναφέρεται κυρίως στο verbum devotorium γράφειν, στη μορφή συνεπιόντων, που είναι τα πρόσωπα στα οποία απευθύνεται η κατάρα και στα ονόματά τους. Οι αριθμοί 2 και 3 αποκαλύπτουν πολλά ανθρωπονύμια, που είναι αρκετά σπάνια και σχολιάζονται λεπτομερώς. Ο αριθμός 8 φαίνεται ότι είναι ένα θραύσμα μολυβδίνου κιβωτιδίου, όπου θα μπορούσε να φυλασσόταν ένα ομοίωμα, που χρησιμοποιούνταν στη μαγεία. Μόνο πέντε κιβωτίδια αυτού του είδους είναι γνωστά σήμερα: τέσσερα στην Αττική και ένα στη Μαύρη θάλασσα.Defixiones from Istros The authors publish eight more or less fragmentary preserved lead curse tablets found by chance in the tumular necropolis from Istros and dating from the 4th century BC. The first one is obviously a defixio iudiciaria, nos. 2-4 are lists of names (perhaps also defixiones iudiciariae), nos. 5-7 are hardly legible, while no. 8 is an inscribed lid. The most important text is revealed by no. 1. The commentary focuses especially on the verbum devotorium γράφειν, on the form συνεπιόντων, on the persons concerned by the curse and on their names. Nos. 2-3 reveal more rather rare personal names commented in detail. No. 8 seems to be a fragment of a lead box in which a "voodoo doll" might have been hidden. Only five boxes of this kind were known until now: four in Attica and one in the Black Sea area.Les auteurs publient huit tablettes de malédiction de plomb conservées d'une manière plus ou moins fragmentaire, trouvées fortuitement dans la nécropole tumulaire d'Istros et datant du IVe siècle av. J.-C. La première est manifestement une defixio iudiciaria, les nos 2-4 sont des listes de noms (sans doute toujours des defixiones iudiciariae), les nos 5-7 sont presque illisibles, alors que le n° 8 est un couvercle de plomb inscrit. Le texte le plus important est révélé par le n° 1 . Le commentaire porte surtout sur le verbum devotorium γράφειν, la forme συνεπιόντων, les personnes concernées par la malédiction et leurs noms. Les nos 2-3 révèlent plusieurs anthroponymes plutôt rares commentés en détail. Le n° 8 semble être un fragment d'une cassette de plomb qui aurait pu abriter une « figurine vaudou ». On ne connaissait jusqu'ici que cinq cassettes de ce genre : quatre en Attique et une en mer Noire.Avram Alexandre, Chiriac Costel, Matei Ionel. Defixiones d'Istros. In: Bulletin de correspondance hellénique. Volume 131, livraison 1, 2007. pp. 383-420

Predictive Models for Fast and Effective Profiling of Kinase Inhibitors

In this study we developed two-dimensional pharmacophore-based random forest models for the effective profiling of kinase inhibitors. One hundred seven prediction models were developed to address distinct kinases spanning over all kinase groups. Rigorous external validation demonstrates excellent virtual screening and classification potential of the predictors and, more importantly, the capacity to prioritize novel chemical scaffolds in large chemical libraries. The models built upon more diverse and more potent compounds tend to exert the highest predictive power. The analysis of ColBioS-FlavRC (Collection of Bioselective Flavonoids and Related Compounds) highlighted several potentially promiscuous derivatives with undesirable selectivity against kinases. The prediction models can be downloaded from www.chembioinf.ro

A Conservative Combined Laser Cryoimmunotherapy Treatment vs. Surgical Excision for Basal Cell Carcinoma

Surgical excision is the standard treatment for basal cell carcinoma (BCC), but it can be challenging in elderly patients and patients with comorbidities. The non-surgical guidelines procedures are usually regarded as monotherapy options. This quasi-experimental, non-randomized, comparative effectiveness study aims to evaluate the efficacy of a combined, conservative, non-surgical BCC treatment, and compare it to standard surgical excision. Patients with primary, non-ulcerated, histopathologically confirmed BCCs were divided into a conservative treatment (129 patients) and a standard surgery subgroup (50 patients). The conservative treatment consisted of ablative CO2 laser, cryosurgery, topical occlusive 5-fluorouracil, and imiquimod. The follow-up examinations were performed 3 months after remission, then every 3 to 6 months, and were extended with telephone follow-ups. Cosmetic-self assessment was recorded during a telephone follow-up. Subjects from the conservative subgroup presented a clearance rate of 99.11%, and a recurrence rate of 0.98%. No recurrences were recorded in the surgical group, nor during the telephone follow-up. There were no differences regarding adverse events (p > 0.05). A superior self-assessment cosmetic outcome was obtained using the conservative method (p < 0.001). This conservative treatment is suitable for elders and patients with comorbidities, is not inferior to surgery in terms of clearance, relapses, or local adverse events, and displays superior cosmetic outcomes

Innovative Solution for Reducing Yarns Hairiness on Ring Spinning Machines

Yarn’s hairiness represents a continuous challenge for spinning technologies. To keep this aspect under control, an almost perfect combination between the construction and performance of the machines, the control of the technological processes through appropriate settings, and the experience of the producers are required. As a consequence, the researchers were preoccupied to adapt or modify the ring frame to produce yarns with a lower degree of hairiness. Spinning triangles as a very demanding area exert a crucial impact both on the distribution of fiber tension and their spatial location in the staple yarn structure. Our study encompasses yarn hairiness reduction employing a device composed of two bars. Various combinations of spindle speeds and contact angles between yarns and bars were tested to examine their effects on yarn hairiness. The study was completed with the optimization of technological parameters using a central, composite, rotating program with two independent variables (spindle speed and contact angle) to establish mathematical models and optimize technological parameters for the reduction of hairiness. The effectiveness and efficiency of this device consist of the easy execution and installation on the existing machines in spinning mills without any constructive adjustments and additional energy consumption

Surveying colloid sedimentation by coplanar waveguides

By using coplanar waveguides, a direct access to the dielectric properties of aqueous solutions of polystyrene beads with different diameters from 330 nm to 10 microns is provided. The relative variation of the transmission parameter with respect to water is monitored, ranging from ~3% obtained for a 9.5% solution with 330 nm diameter beads to ~22% for 10 microns diameter particles at the same concentration. To highlight its applicability in biosensing, the technique was further employed to survey the clustering between biotin and streptavidin-coated beads. The transmission parameter displays a ~50% increase for mixtures containing 9 volumes of biotin and 1 volume of streptavidin-modified beads (4.5 ng/microliter of streptavidin) and reaches ~400% higher values when equal volumes of biotin and streptavidin-coated beads (22.5 ng/microliter of streptavidin) were mixed

Si-based three-dimensional assembly for lithium-ion batteries

Silicon is considered the fulcrum of the next generation lithium-ion systems due to its exceptional capacity and low working voltage. Many instabilities are associated with the huge volume expansion during lithium alloying, generating material degradation and inducing rapid capacity devolution. Thus, a suitable Si-based anode relies on engineered nanostructures that can avoid the lithiation-induced cracking and architectures that can accommodate the volumes changes, while sustaining scalability and simplicity required for commercial adoption. We detail on the fabrication of an intertwined material based on flexuous Si nanowires (f-SiNWs). The large-scale synthesis of f-SiNWs relies on metal assisted chemical etching. A chemical peeling procedure has been developed to facilitate the separation of f-SiNWs from their substrate by adjusting the concentration of oxidizing agent to favor the formation of a porous segment. By scanning probe microscopy techniques, we study the morphological, electrical and mechanical properties of the f-SiNWs. The three-dimensionally-entangled f-SiNWs-based materials are assembled via a vacuum filtration technique with MWCNTs as percolative conductive pathways. In the absence of binders, the cohesion between layers of active materials and the structural integrity of the assembly are offered by f-SiNWs. These materials exhibit improved electrochemical performance with ionic liquids compared to conventional electrolytes. A thin Ni coating on the f-SiNWs has been found to further enhance the cycling life of these materials. The mechanical and electrochemical robustness of the Si-based electrode are mainly assigned to the flexuous nano-architecture of the SiNWs [G. Sandu et al. submitted]

Coplanar waveguide devices: Surveying nanocolloid dynamics

We present a novel class of biosensing devices, based on coplanar waveguides fabricated onto thin glass and working in the frequency interval from 40 MHz to 40 GHz. Specifically, polystyrene beads of different diameters were first studied to establish a robust methodology for surveying the sedimentation dynamics of colloidal aqueous solutions. The relative variation of the transmission parameter with respect to water was monitored over the operational frequency range and for a broad interval of concentrations. The careful comparison between the sedimentation dynamics of polystyrene particles in water and in NaCl aqueous solutions was tackled. A decrease in the sedimentation time, consistent with the screening of an electrical charge at the surface of the colloids, was observed for the saline solutions and quantitatively assessed. Considering the observed variation of the transmission parameter with the particles’ size, the technique was further employed to survey the clustering between biotin and streptavidin-coated nanocolloids. Compared to the reference solutions with biotin-modified beads, the sedimentation rate displayed a 50% increase for mixtures containing 9 volumes of biotin and 1 volume of streptavidin-modified beads [4.5 ng/μL of streptavidin] and reached a 400% increase when equal volumes of biotin and streptavidincoated nanobeads were mixed [22.5 ng/μL of streptavidin]. We’ll discuss the integration within lab-on-chip technologies and the exploitation of these devices for enhanced real-time monitoring of target analytes as well as for surveying soft matter self-assembly in various microfluidic environments

Kinked silicon nanowires-based electrode configuration for lithium-ion batteries

Silicon has been in the spotlight of the next generation anode materials due to its distinctive Li-related features such as the ability to form Li rich compounds, corresponding to an exceptional capacity of 3579 mAh/g at low working voltages. In exchange, many engineering concerns are associated to the structural deformation during lithium alloying that can lead to material pulverization as well as limited cycling life. We detail on an anode configuration based on interconnected kinked Si nanowires (k-SiNWs) fabricated by metal assisted chemical etching. A chemical peeling step is introduced to facilitate the separation of the etched k-SiNWs from their originating Si substrate. The three-dimensional (3D) interconnected k-SiNWs-based anode materials are assembled, using a conventional vacuum filtration technique, with multi-walled carbon nanotubes. The k-SiNWs are expected to be more robust to lithiation-induced stresses as they typically behave like microsprings. In addition, the kinks provide interlocking joints resulting in a fairly resilient anode material. Furthermore, the evaluation of the mechanical properties of the anode assemblies revealed a foam-like architecture that benefits from high porosity. These 3D Si-based assemblies were galvanostatically cycled in conventional electrolytes and ionic liquids. The electrochemical evaluation of the 3D Si-based anode assemblies showed valuable cycling life in ionic liquids compared to conventional electrolytes, retaining 70% of the initial capacity and displaying an average Coulombic efficiency of 97.5% after 50 cycles. Further performance improvements were obtained by coating the k-SiNWs with a 33 nm Ni coating. The exemplary mechanical behavior and electrochemical robustness were assigned to the kinked morphology of the SiNWs