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>

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.

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>

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.

Postdural puncture subdural hematoma or postdural puncture headache? -two cases report-

Aydemir Kale,Hakan Emmez,Özcan Pişkin,Emre Durdağ 대한마취통증의학회 2015 Korean Journal of Anesthesiology Vol.68 No.5

Spinal anesthesia is widely used for many obstetric, gynecological, orthopedic, and urological operations. Subdural hematomas may occur after trauma and are associated with high morbidity and mortality rates. Postdural puncture headache (PDPH) is a benign condition and the most frequent complication of spinal anesthesia. The high rate of headache after spinal anesthesia may mask or delay the diagnosis of subdural hematoma. The true incidence of postdural puncture subdural hematoma (PDPSH) is unknown because most affected patients are probably managed without investigation. Therefore, the true incidence of PDPSH may be greater than suggested by previous reports. The differentiation of headache associated with subdural hematoma from PDPH is crucial. We herein report two cases of bilateral subdural hematoma after epidural anesthesia and emphasize the importance of suspicion for PDPSH and careful evaluation of patients with headache after spinal anesthesia.

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.

An unusual stent migration after endoscopic ultrasound-guided choledochoduodenostomy

Aditya Kale,Sridhar Sundaram,Manish Dodmani 소화기인터벤션의학회 2022 International journal of gastrointestinal interven Vol.11 No.1

Summary of event: Endoscopic ultrasound-guided choledochoduodenostomy (EUS-CD) with the placement of a fully covered self-expandable metal stent (SEMS) is an alternative method to percutaneous transhepatic biliary drainage in cases of failed endoscopic retrograde cholangiopancreatography (ERCP) for malignant distal biliary obstruction. We report the case of a 64-year-old female who underwent EUS-CD with placement of a fully covered SEMS for obstructive jaundice due to distal bile duct obstruction by a pancreatic head mass and failed ERCP. Five months after the procedure, she presented with spontaneous expulsion of the stent in vomitus. She did not have bile leak and jaundice due to the formation of an epithelialized fistulous tract between the bile duct and duodenum (choledocho-duodenal fistula). Teaching point: Delayed distal migration of a fully covered SEMS after EUS-CD can occur. The formation of an epithelialized choledochoduodenal fistula prevented the occurrence of bile leak, pneumoperitoneum and perforation. Re-stenting through the same tract is possible. Stents with antimigration flanges or lumen-apposing metal stents may prevent migration.

An unusual stent migration after endoscopic ultrasound-guided choledochoduodenostomy

Aditya Kale,Sridhar Sundaram,Manish Dodmani 소화기인터벤션의학회 2022 Gastrointestinal Intervention Vol.11 No.1

Summary of event: Endoscopic ultrasound-guided choledochoduodenostomy (EUS-CD) with the placement of a fully covered self-expandable metal stent (SEMS) is an alternative method to percutaneous transhepatic biliary drainage in cases of failed endoscopic retrograde cholangiopancreatography (ERCP) for malignant distal biliary obstruction. We report the case of a 64-year-old female who underwent EUS-CD with placement of a fully covered SEMS for obstructive jaundice due to distal bile duct obstruction by a pancreatic head mass and failed ERCP. Five months after the procedure, she presented with spontaneous expulsion of the stent in vomitus. She did not have bile leak and jaundice due to the formation of an epithelialized fistulous tract between the bile duct and duodenum (choledocho-duodenal fistula). Teaching point: Delayed distal migration of a fully covered SEMS after EUS-CD can occur. The formation of an epithelialized choledochoduodenal fistula prevented the occurrence of bile leak, pneumoperitoneum and perforation. Re-stenting through the same tract is possible. Stents with antimigration flanges or lumen-apposing metal stents may prevent migration.

A Diagnostic Model for Assessing the Knowledge Management Practices of Construction Firms

Serdar Kale,Erkan A. Karaman 대한토목학회 2012 KSCE Journal of Civil Engineering Vol.16 No.4

Knowledge management is rapidly becoming a key organizational capability for creating competitive advantage in the construction industry. The emergence of knowledge management as a key organizational capability for creating competitive advantage poses enormous challenges to executives of construction firms. This paper proposes a model for benchmarking the knowledge management practices of construction firms that can guide and assist construction business executives to meet these challenges. The proposed model incorporates benchmarking and knowledge management concepts with Importance-Performance Analysis (IPA) and Comparative Performance Analysis (CPA) maps. The IPA and CPA maps are visual management tools that have been commonly used for continuous improvements in processes and the performance of firms. Yet they have not been used in the construction management literature or for evaluating the knowledge management practices. The proposed model can be used by construction firms as an internal performance measurement tool to evaluate their knowledge management practices. It can provide powerful diagnostic information to construction business executives of construction firms in order to evaluate their firm’s knowledge management practices, identify their firm’s comparative advantages and disadvantages with regard to each knowledge management practice, and set priorities for managerial actions related to knowledge management practices that need improvement. A real-world case study was conducted by administering a survey to 105 construction firms operating in Turkey and is presented to illustrate the implementation and utility of the proposed model.