Evaluation of marginal discrepancy in metal frameworks fabricated by sintering-based computer-aided manufacturing methods

Kaleli, Necati,Ural, Cagri,Us, Yesim Olcer The Korean Academy of Prosthodonitics 2020 The Journal of Advanced Prosthodontics Vol.12 No.3

PURPOSE. The aim of this in vitro study was to evaluate the effect of sintering procedures on marginal discrepancies of fixed partial metal frameworks fabricated using different sintering-based computer-aided design and computer/aided manufacturing (CAD/CAM) techniques. MATERIALS AND METHODS. Forty resin die models of prepared premolar and molar abutment teeth were fabricated using a three-dimensional (3D) printer and divided into four groups (n = 10) according to the fabrication method of metal frameworks used: HM (via hard milling), SM (via soft metal milling), L25 (via direct metal laser melting [DMLM] with a 25 ㎛ layer thickness), and L50 (via direct DMLM with a 50 ㎛ layer thickness). After the metal frameworks were fabricated and cemented, five vertical marginal discrepancy measurements were recorded in each site (i.e., buccal, facing the pontic, lingual, and facing away from the pontic) of both abutment teeth under a stereomicroscope (×40). Data were statistically analyzed at a significance level of 0.05. RESULTS. No statistically significant differences (P>.05) were found among the four axial sites of metal frameworks fabricated by sintering-based CAD/CAM techniques. The HM and L25 groups showed significantly (P<.001) lower marginal discrepancy values than the SM and L50 groups. CONCLUSION. Marginal discrepancy in the sites facing the pontic was not influenced by the type of sintering procedure. All fabrication methods exhibited clinically acceptable results in terms of marginal discrepancies.

Deriving ratings from a private P2P collaborative scheme

( Murat Okkalioglu ),( Cihan Kaleli ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.9

Privacy-preserving collaborative filtering schemes take privacy concerns into its primary consideration without neglecting the prediction accuracy. Different schemes are proposed that are built upon different data partitioning scenarios such as a central server, two-, multi-party or peer-to-peer network. These data partitioning scenarios have been investigated in terms of claimed privacy promises, recently. However, to the best of our knowledge, any peer-to-peer privacy-preserving scheme lacks such study that scrutinizes privacy promises. In this paper, we apply three different attack techniques by utilizing auxiliary information to derive private ratings of peers and conduct experiments by varying privacy protection parameters to evaluate to what extent peers’ data can be reconstructed.

Evaluation of the accuracy of three different intraoral scanners for endocrown digital impression: An in vitro study

Çağrı Ural,박지만,Necati Kaleli,Esma Çağlayan 대한치과보철학회 2020 대한치과보철학회지 Vol.58 No.4

Purpose: The aim of this in vitro study was to evaluate the accuracy of three different intraoral scanners (IOSs) on digital impressions of different types of endocrown cavity preparations. Materials and methods: Two human mandibular molar teeth were prepared with different endocrown abutment designs: one with a buccal wall (Class 2) and the other without a buccal wall (Class 3). Both cavity designs were scanned using a reference desktop scanner (E3) and three different intraoral scanners: Trios3 (TRI group), Cerec Omnicam (CER group), and i500 (I5 group). The obtained Standard Tessellation Language (.stl) datasets were exported to metrology software. The precision was evaluated based on deviations among repeated scan models recorded by each IOS. The trueness was evaluated based on deviations between the reference data and repeated scans. For detecting interaction, data were statistically analyzed using a univariate analysis of variance (ANOVA) and for analyzing the comparison of the test groups data were analyzed by one-way ANOVA and post-hoc Tukey test at the significance level of .05. Results: The deviation values for both cavity designs in the I5 group were significantly lower than those in the other IOS groups in terms of trueness. For both cavity designs, the TRI group exhibited better precision than the other IOS groups. Conclusion: Different technologies of IOS device’s and different endocrown prepration designs affected the accuracy of the digital scans.

Hierarchical 3D ZnIn₂S₄/graphene nano-heterostructures: their <i>in situ</i> fabrication with dual functionality in solar hydrogen production and as anodes for lithium ion batteries

Kale, Sayali B.,Kalubarme, Ramchandra S.,Mahadadalkar, Manjiri A.,Jadhav, Harsharaj S.,Bhirud, Ashwini P.,Ambekar, Jalinder D.,Park, Chan-Jin,Kale, Bharat B. The Royal Society of Chemistry 2015 Physical Chemistry Chemical Physics Vol.17 No.47

<P>Hierarchical 3D ZnIn2S4/graphene (ZnIn2S4/Gr) nano-heterostructures were successfully synthesized using an in-situ hydrothermal method. The dual functionality of these nano-heterostructures i.e. for solar hydrogen production and lithium ion batteries has been demonstrated for the first time. The ZnIn2S4/Gr nano-heterostructures were optimized by varying the concentrations of graphene for utmost hydrogen production. An inspection of the structure shows the existence of layered hexagonal ZnIn2S4 wrapped in graphene. The reduction of graphene oxide (GO) to graphene was confirmed by Raman and XPS analyses. The morphological analysis demonstrated that ultrathin ZnIn2S4 nanopetals are dispersed on graphene sheets. The optical study reveals the extended absorption edge to the visible region due to the presence of graphene and hence is used as a photocatalyst to transform H2S into eco-friendly hydrogen using solar light. The ZnIn2S4/Gr nano-heterostructure that is comprised of graphene and ZnIn2S4 in a weight ratio of 1 : 99 exhibits enhanced photocatalytically stable hydrogen production i.e. B6365 mmole h(-1) under visible light irradiation using just 0.2 g of nano-heterostructure, which is much higher as compared to bare hierarchical 3D ZnIn2(S4). The heightened photocatalytic activity is attributed to the enhanced charge carrier separation due to graphene which acts as an excellent electron collector and transporter. Furthermore, the usage of nano-heterostructures and pristine ZnIn2S4 as anodes in lithium ion batteries confers the charge capacities of 590 and 320 mA h g(-1) after 220 cycles as compared to their initial reversible capacities of 645 and 523 mA h g(-1), respectively. These nano-heterostructures show high reversible capacity, excellent cycling stability, and high-rate capability indicating their potential as promising anode materials for LIBs. The excellent performance is due to the nanostructuring of ZnIn2S4 and the presence of a graphene layer, which works as a channel for the supply of electrons during the charge-discharge process. More significantly, their dual functionality in energy generation and storage is quite unique and commendable.</P>

The deformation and fracture behaviors of 316L stainless steels fabricated by spark plasma sintering technique under uniaxial tension

Kale, Amol B.,Bag, Atanu,Hwang, Ji-Hyun,Castle, Elinor G.,Reece, Mike J.,Choi, Shi-Hoon Elsevier 2017 Materials science & engineering. properties, micro Vol.707 No.-

<P><B>Abstract</B></P> <P>In this study, 316L stainless steel (SS) specimens with different relative densities were fabricated using the spark plasma sintering (SPS) technique. These SPS specimens were used to capture the effect of microstructure heterogeneity on deformation and fracture behaviors during uniaxial tension. Microstructure analysis indicated that the SPS specimens consisted of fully sintered and partially sintered regions and contained initial pores which are located at the grain boundaries. Mini-tension tests combined with the digital image correlation (DIC) technique were carried out at room temperature to measure the mechanical properties of the SPS specimens and the evolution of strain heterogeneity on tensile specimens during uniaxial tension. In order to reveal the fracture mechanisms of the SPS specimens, the surfaces of the fractured specimens were analyzed via field emission scanning electron microscope (FE-SEM). The fracture mechanism in the fully sintered region was identified as a ductile fracture by the formation of cup-like dimples, while the fracture mechanism in the partially sintered region was identified as a decohesion of the interface between the powder and the matrix.</P>

Confinement of nano CdS in designated glass: a novel functionality of quantum dot–glass nanosystems in solar hydrogen production

Kale, Bharat B.,Baeg, Jin-Ook,Apte, Sanjay K.,Sonawane, Ravindra S.,Naik, Sonali D.,Patil, Kashinath R. Royal Society of Chemistry 2007 Journal of materials chemistry Vol.17 No.40

<P>The present work is the investigation of our novel approach to designing quantum dot–glass nanosystems by confining nano CdS in designated glass and the first employment of such a quantum dot system in solar hydrogen production. The CdS quantum dots were grown in a special glass matrix, which involved a sequence of steps. The obtained glass was of uniformly bright yellow in color and the bulk glass was pulverized to a fine powder of micron size particles. The glass powder was characterized structurally and morphologically. X-Ray diffraction and electron diffraction patterns reveal a hexagonal crystallite system for the CdS quantum dots. Field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray fluorescence spectroscopy and chemical leaching with HCl studies demonstrate that the 2.5 nm size CdS quantum dots distribute homogeneously in a monodispersed form in the glass domain and on the surface with a “partially embedded exposure” configuration. This disposition imparts an excellent photostability against photocorrosion and also a facile catalytic function. Therefore, even a very small amount of CdS quantum dots (0.005 g per gram of glass powder) is able to photodecompose H<SUB>2</SUB>S under visible light (<I>λ</I> ≥ 420 nm) both in alkaline and pure aqueous media and produce solar hydrogen with markedly high quantum yields of 17.5 and 11.4%, respectively at 470 nm. Salient features like reusability after simple washing, corrosionless-stability and remarkable catalytic activity of this quantum dot–glass nanosystem are brought forth by our novel catalyst design and are much acclaimed in large scale solar H<SUB>2</SUB> production.</P> <P>Graphic Abstract</P><P>CdS quantum dots (∼2.5 nm) in a “partially embedded exposure” configuration were grown in a special glass matrix. This nanosystem was employed for the first time for the photocatalytic production of H<SUB>2</SUB> under visible light. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b708269j'> </P>

Multiple band gap energy layered electrode for photoelectrochemical cells

Kale, S.S.,Mane, R.S.,Ganesh, T.,Pawar, B.N.,Han, S.H. Elsevier 2009 CURRENT APPLIED PHYSICS Vol.9 No.2

Using wet chemistry, electrode of multiple band gap energy starting from wide titanium dioxide (TiO<SUB>2</SUB>) to narrow range cadmium selenide (CdSe) is synthesized. Complete utilization of solar spectrum by initializing the film of wide band gap energy (absorbs high energy photons) permitting to narrow band gap films (absorbs low energy photons), is explored in the manuscript. X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectrophotometer techniques were used for the structural, surface morphological and optical studies. The role of every layer of descending band gap energy on the performance of photoelectrochemical cells is demonstrated. The three layered electrode exhibits a good absorbance followed by photoresponse as compared to the bilayers.

Comparison of Ultrasound-Guided Transgluteal and Finger- Guided Transvaginal Pudendal Nerve Block Techniques: Which One is More Effective?

Ahmet Kale,Taner Usta,Gulfem Basol,Isa Cam,Melike Yavuz,Hande G. Aytuluk 대한배뇨장애요실금학회 2019 International Neurourology Journal Vol.23 No.4

Purpose: Pudendal neuralgia (PN) is a painful and disabling condition, which reduces the quality of life as well. Pudendal nerve infiltrations are essential for the diagnosis and the management of PN. The purpose of this study was to compare the effectiveness of finger-guided transvaginal pudendal nerve infiltration (TV-PNI) technique and the ultrasound-guided transgluteal pudendal nerve infiltration (TG-PNI) technique. Methods: Forty patients who underwent PNI for the diagnosis of PN were evaluated. Thirty-five of these 40 patients, who were diagnosed as PN, underwent a total of 70 further unilateral PNI. All the patients underwent PNI for twice after the first diagnostic PNI, 1 week apart. Results: In the ultrasound (US)-guided TG-PNI group, the success rate was 68.8% (11 of 16) in both “pain in the sitting position” and “pain in the region from the anus to the clitoris.” The success rate of blocks in the US-guided TG-PNI group was 75% (12 of 16) in terms of pain during/after intercourse. In the finger-guided TV-PNI group, the success rate was 84.2% in both “pain in the sitting position” and “pain in the region from the anus to the clitoris.” The success rate of blocks in the fingerguided TV-PNI group was 89.5% (17 of 19) in terms of pain during/after intercourse. There was no statistically significant difference in the success rate of the 3 assessed conditions between the 2 groups (P>0.05). Conclusions: The TV-PNI may be an alternative to US-guidance technique as a safe, simple, effective approach in pudendal nerve blocks.

Intrapelvic Nerve Entrapment Syndrome Caused by a Variation of the Intrapelvic Piriformis Muscle and Abnormal Varicose Vessels: A Case Report

Ahmet Kale,Gulfem Basol,Ahmet C. Topcu,Elif C. Gundogdu,Taner Usta,Recep Demirhan 대한배뇨장애요실금학회 2021 International Neurourology Journal Vol.25 No.2

Entrapment neuropathy of the sciatic nerve and pudendal nerve are painful syndromes that are often overlooked by physicians. Laparoscopic surgical interventions for nerve entrapment syndromes of the posterior pelvis focus on removing the compression lesion with the purpose of eliminating the suspected cause of sciatica, as well as pudendal neuralgia. Herein, the authors report the rare event of sciatic and pudendal nerve entrapment, which was caused by aberrant vessels and a variant piriformis muscle bundle, as a seldom-diagnosed cause of sciatica and pelvic pain, for both neurosurgeons and neuropelveologists. The authors present the laparoscopic decompression technique for the pudendal and sciatic nerves by giving our technical “tips and tricks” enriched by a surgical video.

DRL-based intersection traffic efficiency enhancement utilizing 5G-NR-V2I data

사지드,Kale Arati K.,Chang KyungHi 한국통신학회 2023 ICT Express Vol.9 No.6

Recent research on reinforcement learning (RL) based traffic management shows promising results, yet it is a significant issue due to increasing volume of traffic and lack of real time traffic information. Improvements of RL algorithms and vehicle-to-everything (V2X) communications technologies are creating new prospects to achieve better traffic efficiency. This paper proposes a new method, namely Vehicle-to-Infrastructure based Traffic Signal Control (V2I-TSC), to capture realistic traffic state using vehicle-to-infrastructure (V2I) communications under 5G-NR-V2X paradigm. It uses single agent RL framework to optimize a traffic signal control which is trained and evaluated through Simulation of Urban MObility (SUMO) simulator. The experimental results show that our proposed method enhances traffic efficiency at the intersection compared to the general traffic control method.