Fabrication of cell container arrays with overlaid surface topographies.

NARCIS (Netherlands)

Truckenmuller, R.; Giselbrecht, S.; Escalante-Marun, M.; Groenendijk, M.; Papenburg, B.; Rivron, N.; Unadkat, H.; Saile, V.; Subramaniam, V.; Berg, A. van den; Blitterswijk, C. Van; Wessling, M.; Boer, J. den; Stamatialis, D.

2012-01-01

This paper presents cell culture substrates in the form of microcontainer arrays with overlaid surface topographies, and a technology for their fabrication. The new fabrication technology is based on microscale thermoforming of thin polymer films whose surfaces are topographically prepatterned on a

Fabrication of cell container arrays with overlaid surface topographies

NARCIS (Netherlands)

Truckenmüller, Roman; Giselbrecht, Stefan; Escalante-Marun, Maryana; Groenendijk, Max; Papenburg, Bernke; Rivron, Nicolas; Unadkat, Hemant; Saile, Volker; Subramaniam, Vinod; van den Berg, Albert; van Blitterswijk, Clemens; Wessling, Matthias; Boer, Jan de; Stamatialis, Dimitrios

This paper presents cell culture substrates in the form of microcontainer arrays with overlaid surface topographies, and a technology for their fabrication. The new fabrication technology is based on microscale thermoforming of thin polymer films whose surfaces are topographically prepatterned on a

On-chip fabrication of alkali-metal vapor cells utilizing an alkali-metal source tablet

International Nuclear Information System (INIS)

Tsujimoto, K; Hirai, Y; Sugano, K; Tsuchiya, T; Tabata, O; Ban, K; Mizutani, N

2013-01-01

We describe a novel on-chip microfabrication technique for the alkali-metal vapor cell of an optically pumped atomic magnetometer (OPAM), utilizing an alkali-metal source tablet (AMST). The newly proposed AMST is a millimeter-sized piece of porous alumina whose considerable surface area holds deposited alkali-metal chloride (KCl) and barium azide (BaN 6 ), source materials that effectively produce alkali-metal vapor at less than 400 °C. Our experiments indicated that the most effective pore size of the AMST is between 60 and 170 µm. The thickness of an insulating glass spacer holding the AMST was designed to confine generated alkali metal to the interior of the vapor cell during its production, and an integrated silicon heater was designed to seal the device using a glass frit, melted at an optimum temperature range of 460–490 °C that was determined by finite element method thermal simulation. The proposed design and AMST were used to successfully fabricate a K cell that was then operated as an OPAM with a measured sensitivity of 50 pT. These results demonstrate that the proposed concept for on-chip microfabrication of alkali-metal vapor cells may lead to effective replacement of conventional glassworking approaches. (paper)

Rapid Fabrication of Cell-Laden Alginate Hydrogel 3D Structures by Micro Dip-Coating.

Science.gov (United States)

Ghanizadeh Tabriz, Atabak; Mills, Christopher G; Mullins, John J; Davies, Jamie A; Shu, Wenmiao

2017-01-01

Development of a simple, straightforward 3D fabrication method to culture cells in 3D, without relying on any complex fabrication methods, remains a challenge. In this paper, we describe a new technique that allows fabrication of scalable 3D cell-laden hydrogel structures easily, without complex machinery: the technique can be done using only apparatus already available in a typical cell biology laboratory. The fabrication method involves micro dip-coating of cell-laden hydrogels covering the surface of a metal bar, into the cross-linking reagents calcium chloride or barium chloride to form hollow tubular structures. This method can be used to form single layers with thickness ranging from 126 to 220 µm or multilayered tubular structures. This fabrication method uses alginate hydrogel as the primary biomaterial and a secondary biomaterial can be added depending on the desired application. We demonstrate the feasibility of this method, with survival rate over 75% immediately after fabrication and normal responsiveness of cells within these tubular structures using mouse dermal embryonic fibroblast cells and human embryonic kidney 293 cells containing a tetracycline-responsive, red fluorescent protein (tHEK cells).

Design, Modeling, Fabrication & Characterization of Industrial Si Solar Cells

Science.gov (United States)

Chowdhury, Ahrar Ahmed

Photovoltaic is a viable solution towards meeting the energy demand in an ecofriendly environment. To ensure the mass access in photovoltaic electricity, cost effective approach needs to be adapted. This thesis aims towards substrate independent fabrication process in order to achieve high efficiency cost effective industrial Silicon (Si) solar cells. Most cost-effective structures, such as, Al-BSF (Aluminum Back Surface Field), FSF (Front Surface Field) and bifacial cells are investigated in detail to exploit the efficiency potentials. First off, we introduced two-dimensional simulation model to design and modeling of most commonly used Si solar cells in today's PV arena. Best modelled results of high efficiency Al-BSF, FSF and bifacial cells are 20.50%, 22% and 21.68% respectively. Special attentions are given on the metallization design on all the structures in order to reduce the Ag cost. Furthermore, detail design and modeling were performed on FSF and bifacial cells. The FSF cells has potentials to gain 0.42%abs efficiency by combining the emitter design and front surface passivation. The prospects of bifacial cells can be revealed with the optimization of gridline widths and gridline numbers. Since, bifacial cells have metallization on both sides, a double fold cost saving is possible via innovative metallization design. Following modeling an effort is undertaken to reach the modelled result in fabrication the process. We proposed substrate independent fabrication process aiming towards establishing simultaneous processing sequences for both monofacial and bifacial cells. Subsequently, for the contact formation cost effective screen-printed technology is utilized throughout this thesis. The best Al-BSF cell attained efficiency ˜19.40%. Detail characterization was carried out to find a roadmap of achieving >20.50% efficiency Al-BSF cell. Since, n-type cell is free from Light Induced degradation (LID), recently there is a growing interest on FSF cell. Our

Development of remote equipment for a DUPIC fuel fabrication at KAERI

International Nuclear Information System (INIS)

Lee, Jungwon; Kim, Kiho; Park, Geunil; Yang, Myungseung; Song, Keechan

2007-01-01

The DUPIC (Direct Use of spent PWR fuel In CANDU reactors) technology is to directly refabricate CANDU fuel from spent PWR fuel without any separation of the fissile materials and fission products. Thus, the DUPIC fuel material always remains in a highly radioactive state, which requires a remote fuel fabrication in a hot-cell. About 25 pieces of remote equipment including auxiliary systems such as a hot-cell shield plug were developed and installed in a hot cell. In order to supply a high electric current to a sintering furnace in-cell from an outside cell, a shield plug was developed. It consists of three components - a steel shield plug with an embedded spiral cooling line, stepped copper bus bars, and a shielding lead block. Experiments to evaluate the performance of the sintering furnace with the developed shield plug were carried out. It was concluded that, from the experimental results, the newly developed hot-cell shield plug satisfied all the requirements for a remote operation on a sintering furnace. DUPIC fuel pellets and elements were successfully fabricated with the developed remote equipment. (authors)

Fabrication approaches for plasmon-improved photovoltaic cells

DEFF Research Database (Denmark)

Gritti, Claudia; Malureanu, Radu; Kardynal, B.

During this talk we will present various fabrication approaches to improve the performance of photovoltaic (PV) cells by using metallic nanoparticles in order to generate photocurrent below the bandgap. This effect is possible due to the generation of surface plasmon polaritons (SPPs) in optimized...

Thin film solar cell configuration and fabrication method

Science.gov (United States)

Menezes, Shalini

2009-07-14

A new photovoltaic device configuration based on an n-copper indium selenide absorber and a p-type window is disclosed. A fabrication method to produce this device on flexible or rigid substrates is described that reduces the number of cell components, avoids hazardous materials, simplifies the process steps and hence the costs for high volume solar cell manufacturing.

Intrinsic ZnO films fabricated by DC sputtering from oxygen-deficient targets for Cu(In,Ga)Se2 solar cell application

Institute of Scientific and Technical Information of China (English)

Chongyin Yang; DongyunWan; Zhou Wang; Fuqiang Huang

2011-01-01

Intrinsic zinc oxide films, normally deposited by radio frequency (RF) sputtering, are fabricated by direct current (DC) sputtering. The oxygen-deficient targets are prepared via a newly developed double crucible method. The 800-nm-thick film obtaines significantly higher carrier mobility compareing with that of the 800-nm-thick ZnO film. This is achieved by the widely used RF sputtering, which favors the prevention of carrier recombination at the interfaces and reduction of the series resistance of solar cells. The optimal ZnO film is used in a Cu (In, Ga) Se2 (CIGS) solar cell with a high efficiency of 11.57%. This letter demonstrates that the insulating ZnO films can be deposited by DC sputtering from oxygen-deficient ZnO targets to lower the cost of thin film solar cells.%Intrinsic zinc oxide films,normally deposited by radio frequency (RF) sputtering,are fabricated by direct current (DC) sputtering.The oxygen-deficient targets are prepared via a newly developed double crucible method.The 800-nm-thick film obtaines significantly higher carrier mobility compareing with that of the 800-nm-thick ZnO film.This is achieved by the widely used RF sputtering,which favors the prevention of carrier recombination at the interfaces and reduction of the series resistance of solar cells.The optimal ZnO film is used in a Cu (In,Ga) Se2 (C1GS) solar cell with a high efficiency of 11.57％.This letter demonstrates that the insulating ZnO films can be deposited by DC sputtering from oxygen-deficient ZnO targets to lower the cost of thin film solar cells.High resistance transparent intrinsic zinc oxide (i-ZnO)thin film has been widely nsed as the front electrode in transparent electronics and photovoltaic devices because of its low cost and nontoxicity.Owing to its unique characteristics of high transparency and adjustable resistivity in a certain range,the use of i-ZnO thin films as diffusion barrier layers of a-Si/μc-Si,CdTe,and CIGS thin-film solar cells has been advantageous

Fabrication and characterization of tetracyanoquinodimethane/phthalocyanine solar cells

International Nuclear Information System (INIS)

Suzuki, Atsushi; Ohtsuki, Takahiro; Oku, Takeo; Akiyama, Tsuyoshi

2012-01-01

Highlights: ► Heterojunction solar cells of tetracyanoquinodimethane (TCNQ)/copper phthalocyanine (CuPc) and zinc phthalocyanine (ZnPc) were fabricated and characterized. ► The light-induced charge separation with charge transfer was investigated by light-induced current density and optical absorption.. ► In both solar cells of TCNQ/CuPc and TCNQ/ZnPc, the TCNQ thin film worked for strong electron-accepting layer. ► These behaviors would be originated in charge transfer of excited electron from CuPc and ZnPc to TCNQ. ► The photovoltaic mechanism was discussed by the experimental results. - Abstract: Fabrication and characterization of heterojunction solar cells of tetracyanoquinodimethane (TCNQ)/copper phthalocyanine (CuPc) and zinc phthalocyanine (ZnPc) were carried out. The light-induced charge separation with charge transfer was investigated by light-induced current density and optical absorption. In both cases of the TCNQ/CuPc and TCNQ/ZnPc solar cells, the TCNQ thin film worked for strong electron-accepting layer as n-type semiconductor. These behaviors would be originated in charge transfer of excited electron from CuPc and ZnPc to TCNQ. The photovoltaic mechanism was discussed on the basis of the experimental results.

Estimation of radiation exposure for hot cell workers during DUPIC fuel fabrication process in IMEF M6 cell

Energy Technology Data Exchange (ETDEWEB)

Jeon, Yong Bum; Baek, Sang Yeol; Park, Dae Kyu

1997-06-01

DUPIC(Direct Use of spent PWR fuel In CANDU) fuel cycle to utilize the PWR spent fuel in fabricating CANDU fuel, which is expected to reduce not only the total amount of high level radwastes but the energy sources is underway. IMEF M6 cell to be used as DUPIC fuel fabrication facility is refurbished and retrofitted. Radiation exposure for the hot cell worker by dispersion of the radioactive materials during the DUPIC process were estimated on the basis of the hot cell design information. According to the estimation results, DUPIC fuel fabrication process could be run without any severe impacts to the hot cell workers when the ventilation system to maintain the sufficient pressure difference between hotcell and working area and radiation monitoring system is supports the hot cell operation properly. (author). 4 tabs., 6 figs.

Changes of β-cell function after short-term transient intensive insulin treatment in newly diagnosed type 2 diabetes patients

International Nuclear Information System (INIS)

Tian Xiaoping; Zhuang Huiqin; Su Cainu; Xu Ning; Yin Dong; Hui Yuan; Wu Yan

2007-01-01

To evaluate the effect of short-term intensive insulin treatment on β-cell function in newly diagnosed type 2 diabetes patients with apparently hyperglycemia, twenty-four newly diagnosed type 2 diabetes patients with FPG more than 12.0 mmol/L were treated by short-term transient intensive insulin in average 9.04-4.8 days. Their β-cell function was assessed by oral glucose tolerance test. The FPG, HbAlc and HOMA IR of patients were significantly decreased (P<0.01), while the insulin, the Area Under Curve (AUC) of insulin and HOMA β were significantly increased (P<0.01) after the treatment with insulin. Improvement of β-cell function can be induced by short-term intensive insulin treatment for newly diagnosed type 2 diabetes patients with apparently hyperglycemia. (authors)

Hot-cell shielding system for high power transmission in DUPIC fuel fabrication

International Nuclear Information System (INIS)

Kim, K.; Lee, J.; Park, J.; Yang, M.; Park, H.

2000-01-01

This paper presents a newly designed hot-cell shielding system for use in the development of DUPIC (Direct Use of spent PWR fuel In CANDU reactors) fuel at KAERI (Korea Atomic Energy Research Institute). This hot-cell shielding system that was designed to transmit high power to sintering furnace in-cell from the out-of-cell through a thick cell wall has three subsystems - a steel shield plug with embedded spiral cooling line, stepped copper bus bars, and a shielding lead block. The dose-equivalent rates of the hot-cell shielding system and of the apertures between this system and the hot-cell wall were calculated. Calculated results were compared with the allowable dose limit of the existing hot-cell. Experiments for examining the temperature changes of the shielding system developed during normal furnace operation were also carried out. Finally, gamma-ray radiation survey experiments were conducted by Co-60 source. It is demonstrated that, from both calculated and experimental results, the newly designed hot-cell shielding system meets all the shielding requirements of the existing hot-cell facility, enabling high power transmission to the in-cell sintering furnace. (author)

Fabrication of zinc oxide-cuprous oxide photovoltaic cell for teaching ...

African Journals Online (AJOL)

The light related current - voltage characteristics of the fabricated cell and its open circuit voltage for different illumination levels were comparable to those of conventional solar cells. This indicates that it is possible to produce a functional photovoltaic cell through local improvisation that can be used to stimulate the interest ...

Clinical characteristics and beta cell function in Chinese patients with newly diagnosed type 2 diabetes mellitus with different levels of serum triglyceride.

Science.gov (United States)

Zheng, Shuang; Zhou, Huan; Han, Tingting; Li, Yangxue; Zhang, Yao; Liu, Wei; Hu, Yaomin

2015-04-29

To explore clinical characteristics and beta cell function in Chinese patients with newly diagnosed drug naive type 2 diabetes mellitus (T2DM) with different levels of serum triglyceride (TG). Patients with newly diagnosed T2DM (n = 624) were enrolled and divided into different groups according to levels of serum TG. All patients underwent oral glucose tolerance tests and insulin releasing tests. Demographic data, lipid profiles, glucose levels, and insulin profiles were compared between different groups. Basic insulin secretion function index (homeostasis model assessment for beta cell function index, HOMA-β), modified beta cell function index (MBCI), glucose disposition indices (DI), and early insulin secretion function index (insulinogenic index, IGI) were used to evaluate the beta cell function. Patients of newly diagnosed T2DM with hypertriglyceridemia were younger, fatter and had worse lipid profiles, glucose profiles, and high insulin levels than those with normal TG. There is no difference in early phase insulin secretion among groups of newly diagnosed T2DM patients with different TG levels. The basal beta cell function (HOMA-β and MBCI) initially increased along rising TG levels and then decreased as the TG levels rose further. The insulin sensitivity was relatively high in patients with a low level of TG and low with a high level of TG. Hypertriglyceridemia influences clinical characteristics and β cell function of Chinese patients with newly diagnosed T2DM. A better management of dyslipidemia may, to some extent, reduce the effect of lipotoxicity, thereby improving glucose homeostasis in patients with newly diagnosed T2DM.

Fabrication of a miniaturized cell using microsystem technologies for electrochemical applications

International Nuclear Information System (INIS)

Lakard, Boris; Jeannot, Jean-Claude; Spajer, Michel; Herlem, Guillaume; Labachelerie, Michel de; Blind, Pascal; Fahys, Bernard

2005-01-01

A new type of electrochemical cell has been developed for use in electrochemical, chemical and biological applications. Using a platinum microelectrode as working electrode, this cell incorporates a silver microelectrode as reference electrode. These microelectrodes, whose area is equal to 1 μm 2 , were fabricated using photolithography, sputtering, and focused ion beam (FIB) technologies since these micro-fabrication techniques allow us to develop miniaturized electrochemical cells useful either for nanoelectrochemistry or biosensors applications. In this study, we show it is possible to coat a surface by chemical or biological compounds by immersing the microelectrodes in a solution, then setting a difference of potential between the two microelectrodes of the cell. For example, we used this miniaturized cell to realize the electrochemical polymerization of aniline into polyaniline to show that this electrochemical cell is efficient to coat a surface with a thin film of polymer

Low-cost zinc-plated photoanode for fabric-type dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Kong, Lingfeng; Bao, Yunna; Guo, Wanwan; Cheng, Li; Du, Jun; Liu, Renlong [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Wang, Yundong [Department of Chemical Engineering, Tsinghua University, State Key Lab of Chemical Engineering, Beijing 100084 (China); Fan, Xing, E-mail: foxcqdx@cqu.edu.cn [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Tao, Changyuan [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China)

2016-02-15

Graphical abstract: - Highlights: • Fabric-type flexible solar cells have been assembled on Zn-plated wires and meshes. • Metal Zn can improve the carriers transfer over the metal/ZnO nanoarrays interface. • A current increase by ∼6 mA/cm{sup 2} was realized by plating Zn on various metal substrates. • All-solid fabric-type DSSC was also assembled on Zn-plated metal wires. - Abstract: Fabric-type flexible solar cells have been recently proposed as a very promising power source for wearable electronics. To increase the photocurrent of fabric-type flexible solar cells, low-cost zinc-plated wire and mesh photoanodes are assembled for the first time through a mild wet process. Given the protection of the compact protection layer, the DSSC device could benefit from the low work function of Zn and self-repairing behavior on the Zn/ZnO interface. An evident current increase by ∼6 mA/cm{sup 2} could be observed after coating a layer of metal Zn on various metal substrates, such as traditional stainless steel wire. Given the self-repairing behavior on Zn/ZnO interface, the Zn layer can help to improve the interfacial carrier transfer, leading to better photovoltaic performance, for both liquid-type and solid-type cells.

Low-cost zinc-plated photoanode for fabric-type dye-sensitized solar cells

International Nuclear Information System (INIS)

Kong, Lingfeng; Bao, Yunna; Guo, Wanwan; Cheng, Li; Du, Jun; Liu, Renlong; Wang, Yundong; Fan, Xing; Tao, Changyuan

2016-01-01

Graphical abstract: - Highlights: • Fabric-type flexible solar cells have been assembled on Zn-plated wires and meshes. • Metal Zn can improve the carriers transfer over the metal/ZnO nanoarrays interface. • A current increase by ∼6 mA/cm"2 was realized by plating Zn on various metal substrates. • All-solid fabric-type DSSC was also assembled on Zn-plated metal wires. - Abstract: Fabric-type flexible solar cells have been recently proposed as a very promising power source for wearable electronics. To increase the photocurrent of fabric-type flexible solar cells, low-cost zinc-plated wire and mesh photoanodes are assembled for the first time through a mild wet process. Given the protection of the compact protection layer, the DSSC device could benefit from the low work function of Zn and self-repairing behavior on the Zn/ZnO interface. An evident current increase by ∼6 mA/cm"2 could be observed after coating a layer of metal Zn on various metal substrates, such as traditional stainless steel wire. Given the self-repairing behavior on Zn/ZnO interface, the Zn layer can help to improve the interfacial carrier transfer, leading to better photovoltaic performance, for both liquid-type and solid-type cells.

Fabrication of three-dimensional scaffolds using precision extrusion deposition with an assisted cooling device.

Science.gov (United States)

Hamid, Q; Snyder, J; Wang, C; Timmer, M; Hammer, J; Guceri, S; Sun, W

2011-09-01

In the field of biofabrication, tissue engineering and regenerative medicine, there are many methodologies to fabricate a building block (scaffold) which is unique to the target tissue or organ that facilitates cell growth, attachment, proliferation and/or differentiation. Currently, there are many techniques that fabricate three-dimensional scaffolds; however, there are advantages, limitations and specific tissue focuses of each fabrication technique. The focus of this initiative is to utilize an existing technique and expand the library of biomaterials which can be utilized to fabricate three-dimensional scaffolds rather than focusing on a new fabrication technique. An expanded library of biomaterials will enable the precision extrusion deposition (PED) device to construct three-dimensional scaffolds with enhanced biological, chemical and mechanical cues that will benefit tissue generation. Computer-aided motion and extrusion drive the PED to precisely fabricate micro-scaled scaffolds with biologically inspired, porosity, interconnectivity and internal and external architectures. The high printing resolution, precision and controllability of the PED allow for closer mimicry of tissues and organs. The PED expands its library of biopolymers by introducing an assisting cooling (AC) device which increases the working extrusion temperature from 120 to 250 °C. This paper investigates the PED with the integrated AC's capabilities to fabricate three-dimensional scaffolds that support cell growth, attachment and proliferation. Studies carried out in this paper utilized a biopolymer whose melting point is established to be 200 °C. This polymer was selected to illustrate the newly developed device's ability to fabricate three-dimensional scaffolds from a new library of biopolymers. Three-dimensional scaffolds fabricated with the integrated AC device should illustrate structural integrity and ability to support cell attachment and proliferation.

Fabrication of three-dimensional scaffolds using precision extrusion deposition with an assisted cooling device

International Nuclear Information System (INIS)

Hamid, Q; Snyder, J; Wang, C; Guceri, S; Sun, W; Timmer, M; Hammer, J

2011-01-01

In the field of biofabrication, tissue engineering and regenerative medicine, there are many methodologies to fabricate a building block (scaffold) which is unique to the target tissue or organ that facilitates cell growth, attachment, proliferation and/or differentiation. Currently, there are many techniques that fabricate three-dimensional scaffolds; however, there are advantages, limitations and specific tissue focuses of each fabrication technique. The focus of this initiative is to utilize an existing technique and expand the library of biomaterials which can be utilized to fabricate three-dimensional scaffolds rather than focusing on a new fabrication technique. An expanded library of biomaterials will enable the precision extrusion deposition (PED) device to construct three-dimensional scaffolds with enhanced biological, chemical and mechanical cues that will benefit tissue generation. Computer-aided motion and extrusion drive the PED to precisely fabricate micro-scaled scaffolds with biologically inspired, porosity, interconnectivity and internal and external architectures. The high printing resolution, precision and controllability of the PED allow for closer mimicry of tissues and organs. The PED expands its library of biopolymers by introducing an assisting cooling (AC) device which increases the working extrusion temperature from 120 to 250 deg. C. This paper investigates the PED with the integrated AC's capabilities to fabricate three-dimensional scaffolds that support cell growth, attachment and proliferation. Studies carried out in this paper utilized a biopolymer whose melting point is established to be 200 deg. C. This polymer was selected to illustrate the newly developed device's ability to fabricate three-dimensional scaffolds from a new library of biopolymers. Three-dimensional scaffolds fabricated with the integrated AC device should illustrate structural integrity and ability to support cell attachment and proliferation.

Rapid fabrication of detachable three-dimensional tissues by layering of cell sheets with heating centrifuge.

Science.gov (United States)

Haraguchi, Yuji; Kagawa, Yuki; Hasegawa, Akiyuki; Kubo, Hirotsugu; Shimizu, Tatsuya

2018-01-18

Confluent cultured cells on a temperature-responsive culture dish can be harvested as an intact cell sheet by decreasing temperature below 32°C. A three-dimensional (3-D) tissue can be fabricated by the layering of cell sheets. A resulting 3-D multilayered cell sheet-tissue on a temperature-responsive culture dish can be also harvested without any damage by only temperature decreasing. For shortening the fabrication time of the 3-D multilayered constructs, we attempted to layer cell sheets on a temperature-responsive culture dish with centrifugation. However, when a cell sheet was attached to the culture surface with a conventional centrifuge at 22-23°C, the cell sheet hardly adhere to the surface due to its noncell adhesiveness. Therefore, in this study, we have developed a heating centrifuge. In centrifugation (55g) at 36-37°C, the cell sheet adhered tightly within 5 min to the dish without significant cell damage. Additionally, centrifugation accelerated the cell sheet-layering process. The heating centrifugation shortened the fabrication time by one-fifth compared to a multilayer tissue fabrication without centrifugation. Furthermore, the multilayered constructs were finally detached from the dishes by decreasing temperature. This rapid tissue-fabrication method will be used as a valuable tool in the field of tissue engineering and regenerative therapy. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018. © 2018 American Institute of Chemical Engineers.

Prognostic value of regulatory T cells in newly diagnosed chronic myeloid leukemia patients.

Science.gov (United States)

Zahran, Asmaa M; Badrawy, Hosny; Ibrahim, Abeer

2014-08-01

Chronic myeloid leukemia (CML) is a clonal disease, characterized by a reciprocal t(9, 22) that results in a chimeric BCR/ABL fusion gene. Regulatory T cells (Tregs) constitute the main cell population that enables cancer cells to evade immune surveillance. The purpose of our study was to investigate the level of Tregs in newly diagnosed CML patients and to correlate it with the patients' clinical, laboratory and molecular data. We also aimed to assess the effect of treatment using tyrosine kinase inhibitor (TKI) on Treg levels. Tregs were characterized and quantified by flow cytometry in 63 newly diagnosed CML patients and 40 healthy controls. TKI was used in 45 patients with chronic phase CML, and the response to therapy was correlated with baseline Treg levels. The percentages of Tregs were significantly increased in CML patients compared to the controls. Treg numbers were significantly lower in patients with chronic phase CML versus the accelerated and blast phases, and were significantly lower in patients with complete molecular remission (CMR) compared to those patients without CMR. Tregs may play a role in the maintenance of CML. Moreover, the decrease of their levels in patients with CMR suggests that Tregs might have a clinical value in evaluating the effects of therapy.

Single-step laser-based fabrication and patterning of cell-encapsulated alginate microbeads

International Nuclear Information System (INIS)

Kingsley, D M; Dias, A D; Corr, D T; Chrisey, D B

2013-01-01

Alginate can be used to encapsulate mammalian cells and for the slow release of small molecules. Packaging alginate as microbead structures allows customizable delivery for tissue engineering, drug release, or contrast agents for imaging. However, state-of-the-art microbead fabrication has a limited range in achievable bead sizes, and poor control over bead placement, which may be desired to localize cellular signaling or delivery. Herein, we present a novel, laser-based method for single-step fabrication and precise planar placement of alginate microbeads. Our results show that bead size is controllable within 8%, and fabricated microbeads can remain immobilized within 2% of their target placement. Demonstration of this technique using human breast cancer cells shows that cells encapsulated within these microbeads survive at a rate of 89.6%, decreasing to 84.3% after five days in culture. Infusing rhodamine dye into microbeads prior to fluorescent microscopy shows their 3D spheroidal geometry and the ability to sequester small molecules. Microbead fabrication and patterning is compatible with conventional cellular transfer and patterning by laser direct-write, allowing location-based cellular studies. While this method can also be used to fabricate microbeads en masse for collection, the greatest value to tissue engineering and drug delivery studies and applications lies in the pattern registry of printed microbeads. (paper)

Fabrication of Two Columns Dye-Sensitized Solar-Cell

International Nuclear Information System (INIS)

Phyu Sin Khaing Oo; Su Su Hlaing; Khin Lay Thwe; Nwe Ni Khin

2011-12-01

A two columns dye-sensitized solar cell has been fabricated using dye extract form teak leaves. This solar cell was assembled with two 20-30 ohms conductive glasses (one for TiO2 coated electrode and another for carbon coated electrode), TiO2 nano-powder P25, iodide electrolyte solution and soft graphite pencil for carbon coating. It was found that the open circuit voltage Voc was 0.688V and the short circuit Isc was 0.724mA

Fabrication and characterization of poly[diphenylsilane]-based solar cells

International Nuclear Information System (INIS)

Iwase, M; Oku, T; Suzuki, A; Akiyama, T; Tokumitsu, K; Yamada, M; Nakamura, M

2012-01-01

Poly[diphenylsilane] (PDPS)-based photovoltaic cells were fabricated by using mixture solution of PDPS, phosphorus and boron. An influence of phosphorus and boron doping into PDPS on the performance of the photovoltaic device was investigated. The solar cell using fluorine doped tin oxide glass plates provided short-circuit current density of 0.12 mA/cm 2 and open-circuit voltage of 0.28 V under simulated sunlight. Energy levels, formation mechanism and microstructure of the solar cells were discussed.

Glucose Fuel Cells with a MicroChannel Fabricated on Flexible Polyimide Film

Science.gov (United States)

Sano, Ryohei; Fukushi, Yudai; Sasaki, Tsubasa; Mogi, Hiroshi; Koide, Syohei; Ikoma, Ryuta; Akatsuka, Wataru; Tsujimura, Seiya; Nishioka, Yasushiro

2013-12-01

In this work, a glucose fuel cell was fabricated using microfabrication processes assigned for microelectromechanical systems. The fuel cell was equipped with a microchannel to flow an aqueous solution of glucose. The cell was fabricated on a flexible polyimide substrate, and its porous carbon-coated aluminum (Al) electrodes of 2.8 mm in width and 11 mm in length were formed using photolithography and screen printing techniques. Porous carbon was deposited by screen printing of carbon black ink on the Al electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the electrode surfaces. The microchannel with a depth of 200 μm was fabricated using a hot embossing technique. A maximum power of 0.45 μW at 0.5 V that corresponds to a power density of 1.45 μW/cm2 was realized by introducing a 200 mM concentrated glucose solution at room temperature.

Glucose Fuel Cells with a MicroChannel Fabricated on Flexible Polyimide Film

International Nuclear Information System (INIS)

Sano, Ryohei; Fukushi, Yudai; Sasaki, Tsubasa; Mogi, Hiroshi; Koide, Syohei; Ikoma, Ryuta; Nishioka, Yasushiro; Akatsuka, Wataru; Tsujimura, Seiya

2013-01-01

In this work, a glucose fuel cell was fabricated using microfabrication processes assigned for microelectromechanical systems. The fuel cell was equipped with a microchannel to flow an aqueous solution of glucose. The cell was fabricated on a flexible polyimide substrate, and its porous carbon-coated aluminum (Al) electrodes of 2.8 mm in width and 11 mm in length were formed using photolithography and screen printing techniques. Porous carbon was deposited by screen printing of carbon black ink on the Al electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the electrode surfaces. The microchannel with a depth of 200 μm was fabricated using a hot embossing technique. A maximum power of 0.45 μW at 0.5 V that corresponds to a power density of 1.45 μW/cm 2 was realized by introducing a 200 mM concentrated glucose solution at room temperature

Fabrication of three-dimensional scaffolds using precision extrusion deposition with an assisted cooling device

Energy Technology Data Exchange (ETDEWEB)

Hamid, Q; Snyder, J; Wang, C; Guceri, S; Sun, W [Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA (United States); Timmer, M; Hammer, J, E-mail: sunwei@drexel.edu [Advanced Technologies and Regenerative Medicine, Somerville, NJ (United States)

2011-09-15

In the field of biofabrication, tissue engineering and regenerative medicine, there are many methodologies to fabricate a building block (scaffold) which is unique to the target tissue or organ that facilitates cell growth, attachment, proliferation and/or differentiation. Currently, there are many techniques that fabricate three-dimensional scaffolds; however, there are advantages, limitations and specific tissue focuses of each fabrication technique. The focus of this initiative is to utilize an existing technique and expand the library of biomaterials which can be utilized to fabricate three-dimensional scaffolds rather than focusing on a new fabrication technique. An expanded library of biomaterials will enable the precision extrusion deposition (PED) device to construct three-dimensional scaffolds with enhanced biological, chemical and mechanical cues that will benefit tissue generation. Computer-aided motion and extrusion drive the PED to precisely fabricate micro-scaled scaffolds with biologically inspired, porosity, interconnectivity and internal and external architectures. The high printing resolution, precision and controllability of the PED allow for closer mimicry of tissues and organs. The PED expands its library of biopolymers by introducing an assisting cooling (AC) device which increases the working extrusion temperature from 120 to 250 deg. C. This paper investigates the PED with the integrated AC's capabilities to fabricate three-dimensional scaffolds that support cell growth, attachment and proliferation. Studies carried out in this paper utilized a biopolymer whose melting point is established to be 200 deg. C. This polymer was selected to illustrate the newly developed device's ability to fabricate three-dimensional scaffolds from a new library of biopolymers. Three-dimensional scaffolds fabricated with the integrated AC device should illustrate structural integrity and ability to support cell attachment and proliferation.

Elimination of remaining undifferentiated induced pluripotent stem cells in the process of human cardiac cell sheet fabrication using a methionine-free culture condition.

Science.gov (United States)

Matsuura, Katsuhisa; Kodama, Fumiko; Sugiyama, Kasumi; Shimizu, Tatsuya; Hagiwara, Nobuhisa; Okano, Teruo

2015-03-01

Cardiac tissue engineering is a promising method for regenerative medicine. Although we have developed human cardiac cell sheets by integration of cell sheet-based tissue engineering and scalable bioreactor culture, the risk of contamination by induced pluripotent stem (iPS) cells in cardiac cell sheets remains unresolved. In the present study, we established a novel culture method to fabricate human cardiac cell sheets with a decreased risk of iPS cell contamination while maintaining viabilities of iPS cell-derived cells, including cardiomyocytes and fibroblasts, using a methionine-free culture condition. When cultured in the methionine-free condition, human iPS cells did not survive without feeder cells and could not proliferate or form colonies on feeder cells or in coculture with cells for cardiac cell sheet fabrication. When iPS cell-derived cells after the cardiac differentiation were transiently cultured in the methionine-free condition, gene expression of OCT3/4 and NANOG was downregulated significantly compared with that in the standard culture condition. Furthermore, in fabricated cardiac cell sheets, spontaneous and synchronous beating was observed in the whole area while maintaining or upregulating the expression of various cardiac and extracellular matrix genes. These findings suggest that human iPS cells are methionine dependent and a methionine-free culture condition for cardiac cell sheet fabrication might reduce the risk of iPS cell contamination.

Patterning cell using Si-stencil for high-throughput assay

KAUST Repository

Wu, Jinbo

2011-01-01

In this communication, we report a newly developed cell pattering methodology by a silicon-based stencil, which exhibited advantages such as easy handling, reusability, hydrophilic surface and mature fabrication technologies. Cell arrays obtained by this method were used to investigate cell growth under a temperature gradient, which demonstrated the possibility of studying cell behavior in a high-throughput assay. This journal is © The Royal Society of Chemistry 2011.

Design & Fabrication of a High-Voltage Photovoltaic Cell

Energy Technology Data Exchange (ETDEWEB)

Felder, Jennifer; /North Carolina State U. /SLAC

2012-09-05

Silicon photovoltaic (PV) cells are alternative energy sources that are important in sustainable power generation. Currently, applications of PV cells are limited by the low output voltage and somewhat low efficiency of such devices. In light of this fact, this project investigates the possibility of fabricating high-voltage PV cells on float-zone silicon wafers having output voltages ranging from 50 V to 2000 V. Three designs with different geometries of diffusion layers were simulated and compared in terms of metal coverage, recombination, built-in potential, and conduction current density. One design was then chosen and optimized to be implemented in the final device design. The results of the simulation serve as a feasibility test for the design concept and provide supportive evidence of the effectiveness of silicon PV cells as high-voltage power supplies.

A Novel Silicon-based Wideband RF Nano Switch Matrix Cell and the Fabrication of RF Nano Switch Structures

Directory of Open Access Journals (Sweden)

Yi Xiu YANG

2011-12-01

Full Text Available This paper presents the concept of RF nano switch matrix cell and the fabrication of RF nano switch. The nano switch matrix cell can be implemented into complex switch matrix for signal routing. RF nano switch is the decision unit for the matrix cell; in this research, it is fabricated on a tri-layer high-resistivity-silicon substrate using surface micromachining approach. Electron beam lithography is introduced to define the pattern and IC compatible deposition process is used to construct the metal layers. Silicon-based nano switch fabricated by IC compatible process can lead to a high potential of system integration to perform a cost effective system-on-a-chip solution. In this paper, simulation results of the designed matrix cell are presented; followed by the details of the nano structure fabrication and fabrication challenges optimizations; finally, measurements of the fabricated nano structure along with analytical discussions are also discussed.

Binder Jetting: A Novel Solid Oxide Fuel-Cell Fabrication Process and Evaluation

Science.gov (United States)

Manogharan, Guha; Kioko, Meshack; Linkous, Clovis

2015-03-01

With an ever-growing concern to find a more efficient and less polluting means of producing electricity, fuel cells have constantly been of great interest. Fuel cells electrochemically convert chemical energy directly into electricity and heat without resorting to combustion/mechanical cycling. This article studies the solid oxide fuel cell (SOFC), which is a high-temperature (100°C to 1000°C) ceramic cell made from all solid-state components and can operate under a wide range of fuel sources such as hydrogen, methanol, gasoline, diesel, and gasified coal. Traditionally, SOFCs are fabricated using processes such as tape casting, calendaring, extrusion, and warm pressing for substrate support, followed by screen printing, slurry coating, spray techniques, vapor deposition, and sputter techniques, which have limited control in substrate microstructure. In this article, the feasibility of engineering the porosity and configuration of an SOFC via an additive manufacturing (AM) method known as binder jet printing was explored. The anode, cathode and oxygen ion-conducting electrolyte layers were fabricated through AM sequentially as a complete fuel cell unit. The cell performance was measured in two modes: (I) as an electrolytic oxygen pump and (II) as a galvanic electricity generator using hydrogen gas as the fuel. An analysis on influence of porosity was performed through SEM studies and permeability testing. An additional study on fuel cell material composition was conducted to verify the effects of binder jetting through SEM-EDS. Electrical discharge of the AM fabricated SOFC and nonlinearity of permeability tests show that, with additional work, the porosity of the cell can be modified for optimal performance at operating flow and temperature conditions.

Structure and properties of new natural cellulose fabrics from Cordia dichotoma

CSIR Research Space (South Africa)

Jayaramudu, J

2011-10-01

Full Text Available Natural cellulose fabrics were newly identified from the branches of the Cordia dichotoma. The structure of the fabrics was analysed by FTIR and X-ray diffraction. The net-like morphologies of the untreated, bleached and 5% NaOH (alkali) treated...

Newly developed chitosan-silver hybrid nanoparticles: biosafety and apoptosis induction in HepG2 cells

International Nuclear Information System (INIS)

El-Sherbiny, Ibrahim M.; Salih, Ehab; Yassin, Abdelrahman M.; Hafez, Elsayed E.

2016-01-01

The present study reports the biosafety assessment, the exact molecular effects, and apoptosis induction of newly developed chitosan-silver hybrid nanoparticles (Cs–Ag NPs) in HepG2 cells. The investigated hybrid NPs were green synthesized using Cs/grape leaves aqueous extract (Cs/GLE) or Cs/GLE NPs as reducing and stabilizing agents. The successful formation of Cs/GLE NPs and Cs–Ag hybrid NPs has been confirmed by UV–Vis spectrophotometry, FTIR spectroscopy, XRD, and HRTEM. From the TEM analysis, the prepared Cs/GLE NPs are uniform and spherical with an average size of 150 nm, and the AgNPs (5–10 nm) were formed mainly on their surface. The UV–Vis spectra of Cs–Ag NPs showed a surface plasmon resonance (SPR) peak at about 450 nm confirming their formation. The synthesized Cs–Ag NPs were found to be crystalline as shown by XRD patterns with fcc phase oriented along the (111), (200), (220), and (311) planes. The cytotoxicity patterns, the antiproliferative activities, and the possible mechanisms of anticancer activity at molecular level of the newly developed Cs–Ag hybrid NPs were investigated. Cytotoxicity patterns of all the preparations demonstrated that the nontoxic treatment concentrations are ranged from 0.39 to 50 %, and many of the newly prepared Cs–Ag hybrid NPs showed high anticancer activities against HpG2 cells, and induced cellular apoptosis by downregulating BCL2 gene and upregulating P53.Graphical Abstract

Newly developed chitosan-silver hybrid nanoparticles: biosafety and apoptosis induction in HepG2 cells

Energy Technology Data Exchange (ETDEWEB)

El-Sherbiny, Ibrahim M., E-mail: ielsherbiny@Zewailcity.edu.eg; Salih, Ehab [Zewail City of Science and Technology, Center for Materials Science (Egypt); Yassin, Abdelrahman M. [Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technology Applications, Biopharmaceutical Product Research Department (Egypt); Hafez, Elsayed E. [City of Scientific Research and Technology Applications, Plant Protection and Biomolecular Diagnosis Department (Egypt)

2016-07-15

The present study reports the biosafety assessment, the exact molecular effects, and apoptosis induction of newly developed chitosan-silver hybrid nanoparticles (Cs–Ag NPs) in HepG2 cells. The investigated hybrid NPs were green synthesized using Cs/grape leaves aqueous extract (Cs/GLE) or Cs/GLE NPs as reducing and stabilizing agents. The successful formation of Cs/GLE NPs and Cs–Ag hybrid NPs has been confirmed by UV–Vis spectrophotometry, FTIR spectroscopy, XRD, and HRTEM. From the TEM analysis, the prepared Cs/GLE NPs are uniform and spherical with an average size of 150 nm, and the AgNPs (5–10 nm) were formed mainly on their surface. The UV–Vis spectra of Cs–Ag NPs showed a surface plasmon resonance (SPR) peak at about 450 nm confirming their formation. The synthesized Cs–Ag NPs were found to be crystalline as shown by XRD patterns with fcc phase oriented along the (111), (200), (220), and (311) planes. The cytotoxicity patterns, the antiproliferative activities, and the possible mechanisms of anticancer activity at molecular level of the newly developed Cs–Ag hybrid NPs were investigated. Cytotoxicity patterns of all the preparations demonstrated that the nontoxic treatment concentrations are ranged from 0.39 to 50 %, and many of the newly prepared Cs–Ag hybrid NPs showed high anticancer activities against HpG2 cells, and induced cellular apoptosis by downregulating BCL2 gene and upregulating P53.Graphical Abstract.

Research, Development and Fabrication of Lithium Solar Cells, Part 2

Science.gov (United States)

Iles, P. A.

1972-01-01

The development and fabrication of lithium solar cells are discussed. Several single-step, lithium diffusion schedules using lower temperatures and times are described. A comparison was made using evaporated lithium metal as the lithium source, and greatly improved consistency in lithium concentrations was obtained. It was possible to combine all processing steps to obtain lithium doped cells of high output which also contained adequate lithium to ensure good recoverability.

Study on the Fabrication of Paint-Type Si Quantum Dot-Sensitized Solar Cells

Science.gov (United States)

Seo, Hyunwoong; Son, Min-Kyu; Kim, Hee-Je; Wang, Yuting; Uchida, Giichiro; Kamataki, Kunihiro; Itagaki, Naho; Koga, Kazunori; Shiratani, Masaharu

2013-10-01

Quantum dots (QDs) have attracted much attention with their quantum characteristics in the research field of photochemical solar cells. Si QD was introduced as one of alternatives to conventional QD materials. However, their large particles could not penetrate inside TiO2 layer. Therefore, this work proposed the paint-type Si QD-sensitized solar cell. Its heat durability was suitable for the fabrication of paint-type solar cell. Si QDs were fabricated by multihollow discharge plasma chemical vapor deposition and characterized. The paste type, sintering temperature, and Si ratio were controlled and analyzed for better performance. Finally, its performance was enhanced by ZnS surface modification and the whole process was much simplified without sensitizing process.

Fabrication and characterization of solid oxide cells for energy conversion and storage

Science.gov (United States)

Yang, Chenghao

2011-12-01

There has been an increasing interest in clean and renewable energy generation for highlighted energy and environmental concerns. Solid oxide cells (SOCs) have been considered as one of the promising technologies, since they can be operated efficiently both in electrolysis mode by generating hydrogen through steam electrolysis and fuel cell mode by electrochemically combining fuel with oxidant. The present work is devoted to performing a fundamental study of SOC in both fuel cell mode for power generation and electrolysis mode for fuel production. The research work on SOCs that can be operated reversibly for power generation and fuel production has been conducted in the following six projects: (1) High performance solid oxide electrolysis cell (SOEC) Fabrication of novel structured SOEC oxygen electrode with the conventional and commercial solid oxide fuel cell materials by screen-printing and infiltration fabrication methods. The microstructure, electrochemical properties and durability of SOECs has been investigated. It was found that the LSM infiltrated cell has an area specific resistance (ASR) of 0.20 Ω cm2 at 900°C at open circuit voltage with 50% absolute humidity (AH), which is relatively lower than that of the cell with LSM-YSZ oxygen electrode made by a conventional mixing method. Electrolysis cell with LSM infiltrated oxygen electrode has demonstrated stable performance under electrolysis operation with 0.33 A/cm2 and 50 vol.% AH at 800°C. (2) Advanced performance high temperature micro-tubular solid oxide fuel cell (MT-SOFC) Phase-inversion, dip-coating, high temperature co-sintering process and impregnation method were used to fabricate micro-tubular solid oxide fuel cell. The micro-structure of the micro-tubular fuel cell will be investigated and the power output and thermal robustness has been evaluated. High performance and rapid start-up behavior have been achieved, indicates that the MT-SOFC developed in this work can be a promising technology

Composition-graded nanowire solar cells fabricated in a single process for spectrum-splitting photovoltaic systems.

Science.gov (United States)

Caselli, Derek; Liu, Zhicheng; Shelhammer, David; Ning, Cun-Zheng

2014-10-08

Nanomaterials such as semiconductor nanowires have unique features that could enable novel optoelectronic applications such as novel solar cells. This paper aims to demonstrate one such recently proposed concept: Monolithically Integrated Laterally Arrayed Multiple Band gap (MILAMB) solar cells for spectrum-splitting photovoltaic systems. Two cells with different band gaps were fabricated simultaneously in the same process on a single substrate using spatially composition-graded CdSSe alloy nanowires grown by the Dual-Gradient Method in a chemical vapor deposition system. CdSSe nanowire ensemble devices tested under 1 sun AM1.5G illumination achieved open-circuit voltages up to 307 and 173 mV and short-circuit current densities as high as 0.091 and 0.974 mA/cm(2) for the CdS- and CdSe-rich cells, respectively. The open-circuit voltages were roughly three times those of similar CdSSe film cells fabricated for comparison due to the superior optical quality of the nanowires. I-V measurements were also performed using optical filters to simulate spectrum-splitting. The open-circuit voltages and fill factors of the CdS-rich subcells were uniformly larger than the corresponding CdSe-rich cells for similar photon flux, as expected. This suggests that if all wires can be contacted, the wide-gap cell is expected to have greater output power than the narrow-gap cell, which is the key to achieving high efficiencies with spectrum-splitting. This paper thus provides the first proof-of-concept demonstration of simultaneous fabrication of MILAMB solar cells. This approach to solar cell fabrication using single-crystal nanowires for spectrum-splitting photovoltaics could provide a future low-cost high-efficiency alternative to the conventional high-cost high-efficiency tandem cells.

Application of dopant-free hole transport materials for perovskite solar cells

International Nuclear Information System (INIS)

Franckevincius, M.; Gulbinas, V.; Gratzel, M.; Zakeeruddin, S.; Pauerle, P.; Mishra, A.; Steck, C.

2015-01-01

In this work we present the synthesis, characterization and application of a series of additive and dopant free hole transport materials (HTM) for solid-state perovskite-based solar cells. Newly synthesized HTMs showed strong absorption in the visible spectral range and suitable HOMO-LUMO energy levels for the application for methylammonium lead(II) iodide (CH_3NH_3PbI_3) perovskite. Dopant-free perovskite solar cells have been fabricated using CH_3NH_3PbI_3 perovskite and the newly synthesized HTMs following sequential deposition method, which allows us to reach power conversion efficiencies as high as 11.4 %. The easy of synthesis, low cost and relatively high performance of newly synthesized HTMs has great prospects for commercial applications in the near-future. (authors)

Fabrication of thermo-responsive PNIPAAm-g-ETFE for cell culture dishes by pre-irradiation grafting

Science.gov (United States)

Yamahara, Yumi; Nagasawa, Naotsugu; Taguchi, Mitsumasa; Oshima, Akihiro; Washio, Masakazu

2018-01-01

Thermo-responsive templates for the cell cultivation based on Poly(tetrafluoroethylene-co-ethylene) (ETFE) were fabricated by pre-irradiation grafting of N-isoproplyacrylamide (NIPAAm) monomer by electron beam (EB) irradiation under nitrogen gas atmosphere at room temperature, and their characteristic properties were studied. The detachment of cultured HeLa cells from fabricated thermo-responsive templates were attempted. Furthermore, the reaction mechanism is proposed using ESR spectroscopy and FT-IR spectroscopy. It is confirmed that the cultured HeLa cells were detached from fabricated thermo-responsive templates at 20 °C. Water contact angle analysis indicated that obtained templates had thermo-response around 30 °C. It is suggested that the grafted polymer chains would mainly react with peroxy radicals (-CF2-CF(OO･)-) on tetrafluoroethylene unit in ETFE.

Solar cell fabricated on welded thin flexible silicon

Directory of Open Access Journals (Sweden)

Hessmann Maik Thomas

2015-01-01

Full Text Available We present a thin-film crystalline silicon solar cell with an AM1.5 efficiency of 11.5% fabricated on welded 50 μm thin silicon foils. The aperture area of the cell is 1.00 cm2. The cell has an open-circuit voltage of 570 mV, a short-circuit current density of 29.9 mA cm-2 and a fill factor of 67.6%. These are the first results ever presented for solar cells on welded silicon foils. The foils were welded together in order to create the first thin flexible monocrystalline band substrate. A flexible band substrate offers the possibility to overcome the area restriction of ingot-based monocrystalline silicon wafers and the feasibility of a roll-to-roll manufacturing. In combination with an epitaxial and layer transfer process a decrease in production costs can be achieved.

Low-cost zinc-plated photoanode for fabric-type dye-sensitized solar cells

Science.gov (United States)

Kong, Lingfeng; Bao, Yunna; Guo, Wanwan; Cheng, Li; Du, Jun; Liu, Renlong; Wang, Yundong; Fan, Xing; Tao, Changyuan

2016-02-01

Fabric-type flexible solar cells have been recently proposed as a very promising power source for wearable electronics. To increase the photocurrent of fabric-type flexible solar cells, low-cost zinc-plated wire and mesh photoanodes are assembled for the first time through a mild wet process. Given the protection of the compact protection layer, the DSSC device could benefit from the low work function of Zn and self-repairing behavior on the Zn/ZnO interface. An evident current increase by ∼6 mA/cm2 could be observed after coating a layer of metal Zn on various metal substrates, such as traditional stainless steel wire. Given the self-repairing behavior on Zn/ZnO interface, the Zn layer can help to improve the interfacial carrier transfer, leading to better photovoltaic performance, for both liquid-type and solid-type cells.

Fabrication and characterization of anode-supported micro-tubular solide oxide fuel cell by phase inversion method

Science.gov (United States)

Ren, Cong

Nowadays, the micro-tubular solid oxide fuel cells (MT-SOFCs), especially the anode supported MT-SOFCs have been extensively developed to be applied for SOFC stacks designation, which can be potentially used for portable power sources and vehicle power supply. To prepare MT-SOFCs with high electrochemical performance, one of the main strategies is to optimize the microstructure of the anode support. Recently, a novel phase inversion method has been applied to prepare the anode support with a unique asymmetrical microstructure, which can improve the electrochemical performance of the MT-SOFCs. Since several process parameters of the phase inversion method can influence the pore formation mechanism and final microstructure, it is essential and necessary to systematically investigate the relationship between phase inversion process parameters and final microstructure of the anode supports. The objective of this study is aiming at correlating the process parameters and microstructure and further preparing MT-SOFCs with enhanced electrochemical performance. Non-solvent, which is used to trigger the phase separation process, can significantly influence the microstructure of the anode support fabricated by phase inversion method. To investigate the mechanism of non-solvent affecting the microstructure, water and ethanol/water mixture were selected for the NiO-YSZ anode supports fabrication. The presence of ethanol in non-solvent can inhibit the growth of the finger-like pores in the tubes. With the increasing of the ethanol concentration in the non-solvent, a relatively dense layer can be observed both in the outside and inside of the tubes. The mechanism of pores growth and morphology obtained by using non-solvent with high concentration ethanol was explained based on the inter-diffusivity between solvent and non-solvent. Solvent and non-solvent pair with larger Dm value is benefit for the growth of finger-like pores. Three cells with different anode geometries was

CdTeO3 Deposited Mesoporous NiO Photocathode for a Solar Cell

Directory of Open Access Journals (Sweden)

Chuan Zhao

2014-01-01

Full Text Available Semiconductor sensitized NiO photocathodes have been fabricated by successive ionic layer adsorption and reaction (SILAR method depositing CdTeO3 quantum dots onto mesoscopic NiO films. A solar cell using CdTeO3 deposited NiO mesoporous photocathode has been fabricated. It yields a photovoltage of 103.7 mV and a short-circuit current density of 0.364 mA/cm2. The incident photon to current conversion efficiency (IPCE value is found to be 12% for the newly designed NiO/CdTeO3 solar cell. It shows that the p-type NiO/CdTeO3 structure could be successfully utilized to fabricate p-type solar cell.

Fabricating 40 µm-thin silicon solar cells with different orientations by using SLiM-cut method

Science.gov (United States)

Wang, Teng-Yu; Chen, Chien-Hsun; Shiao, Jui-Chung; Chen, Sung-Yu; Du, Chen-Hsun

2017-10-01

Thin silicon foils with different crystal orientations were fabricated using the stress induced lift-off (SLiM-cut) method. The thickness of the silicon foils was approximately 40 µm. The ≤ft foil had a smoother surface than the ≤ft foil. With surface passivation, the minority carrier lifetimes of the ≤ft and ≤ft silicon foil were 1.0 µs and 1.6 µs, respectively. In this study, 4 cm2-thin silicon solar cells with heterojunction structures were fabricated. The energy conversion efficiencies were determined to be 10.74% and 14.74% for the ≤ft and ≤ft solar cells, respectively. The surface quality of the silicon foils was determined to affect the solar cell character. This study demonstrated that fabricating the solar cell by using silicon foil obtained from the SLiM-cut method is feasible.

Fabrication of dye sensitized solar cells with a double layer photoanode

Directory of Open Access Journals (Sweden)

M. Pirhadi

2016-01-01

Full Text Available Dye sensitized solar cell was fabricated from a double layer photoanode. First, TiO2 nanoparticles  were synthesized by hydrothermal method. These TiO2 NPs were deposited on FTO glasses by electrophoretic deposition  method in applied voltage of 5 V and EPD time of 2.5-10 min. Then TiO2 hollow spheres (HSs were synthesized by sacrificed template method with Carbon Spheres as template and TTIP as precursor. Then these template scarified and the hollow structures found. Since the HSs paste was prepared as same method of prepared TiO2 nano particles and this paste was deposited on last layer by Dr. Blade method. The prepared photoanodes was soaped in N-719 dye after sintering in 500 ÚC. The dye sensitized solar cells  were fabricated with the finalized double layer photoanodes. The best photovoltaic characteristics of the optimized cell were 734 mV, 13.16 mA/cm2, 62% and 5.96% for Voc, Jsc, F.F. and efficiency respectively.

Dopant ink composition and method of fabricating a solar cell there from

Energy Technology Data Exchange (ETDEWEB)

Loscutoff, Paul; Wu, Kahn; Molesa, Steven Edward

2017-10-25

Dopant ink compositions and methods of fabricating solar cells there from are described. A dopant ink composition may include a cross-linkable matrix precursor, a bound dopant species, and a solvent. A method of fabricating a solar cell may include delivering a dopant ink composition to a region above a substrate. The dopant ink composition includes a cross-linkable matrix precursor, a bound dopant species, and a solvent. The method also includes baking the dopant ink composition to remove a substantial portion of the solvent of the dopant ink composition, curing the baked dopant ink composition to cross-link a substantial portion of the cross-linkable matrix precursor of the dopant ink composition, and driving dopants from the cured dopant ink composition toward the substrate.

Dopant ink composition and method of fabricating a solar cell there from

Science.gov (United States)

Loscutoff, Paul; Wu, Kahn; Molesa, Steven Edward

2015-03-31

Dopant ink compositions and methods of fabricating solar cells there from are described. A dopant ink composition may include a cross-linkable matrix precursor, a bound dopant species, and a solvent. A method of fabricating a solar cell may include delivering a dopant ink composition to a region above a substrate. The dopant ink composition includes a cross-linkable matrix precursor, a bound dopant species, and a solvent. The method also includes baking the dopant ink composition to remove a substantial portion of the solvent of the dopant ink composition, curing the baked dopant ink composition to cross-link a substantial portion of the cross-linkable matrix precursor of the dopant ink composition, and driving dopants from the cured dopant ink composition toward the substrate.

Low temperature fabrication of perovskite solar cells with TiO2 nanoparticle layers

International Nuclear Information System (INIS)

Kanayama, Masato; Oku, Takeo; Suzuki, Atsushi; Yamada, Masahiro; Sakamoto, Hiroki; Minami, Satoshi; Kohno, Kazufumi

2016-01-01

TiO 2 /CH 3 NH 3 PbI 3 -based photovoltaic devices were fabricated by a spin-coating method using a mixture solution. TiO 2 require high-temperature processing to achieve suitably high carrier mobility. TiO 2 electron transport layers and TiO 2 scaffold layers for the perovskite were fabricated from TiO 2 nanoparticles with different grain sizes. The photovoltaic properties and microstructures of solar cells were characterized. Nanoparticle sizes of these TiO 2 were 23 nm and 3 nm and the performance of solar cells was improved by combination of two TiO 2 nanoparticles

Sex Differences in Stress and Group Housing Effects on the Number of Newly Proliferated Cells and Neuroblasts in Middle-Aged Dentate Gyrus.

Science.gov (United States)

Tzeng, Wen-Yu; Wu, Hsin-Hua; Wang, Ching-Yi; Chen, Jin-Chung; Yu, Lung; Cherng, Chianfang G

2016-01-01

Sex differences in stress and coping responses have been frequently documented in aged people, while whether such differences in aged people may appear at the middle age are unknown. This study was undertaken to study the impact of acute stress and social interaction on early neurogenesis in the dentate gyrus (DG) and hippocampus-related memory in two sexes of middle-aged mice. The number of newly proliferated cells, neuroblasts in DG, the object recognition and location memory in 9-month-old male and female C57BL/6N mice were assessed under baseline conditions as well as following an acute stressor regimen and group housing. Three conspecific companions, serving as "the housing group," were used to model the social interaction throughout the stressor regimen. Males had lower numbers of newly proliferated cells and neuroblasts under baseline conditions as compared to females. The stressor regimen caused rapid decreases in the number of newly proliferated cells and neuroblasts in female DG but no obvious changes were observed in male DG. Group housing, regardless of companions' age, prevented the stress-induced decreases in the number of newly proliferated cells and neuroblasts in female DG. In contrast, the presence of young or age-matched companions potentiated the stress effect in males by decreasing the number of newly proliferated cells and neuroblasts. Finally, neither the stressor regimen nor group housing affected mouse performances in the object recognition and location memory in either sex. These findings, taken together, provide evidence to support a notion that middle-aged females appear to demonstrate more stress susceptibility on early neurogenesis in DG as compared to middle-aged males, although the hippocampus-related memory performances are comparable and not affected by stress in these males and females. Experiencing stress, middle-aged females are more prone to benefit from social interaction as compared to middle-aged males in this regard. We

Fabrication of three-dimensional porous cell-laden hydrogel for tissue engineering

International Nuclear Information System (INIS)

Hwang, Chang Mo; Sant, Shilpa; Masaeli, Mahdokht; Kachouie, Nezamoddin N; Zamanian, Behnam; Khademhosseini, Ali; Lee, Sang-Hoon

2010-01-01

For tissue engineering applications, scaffolds should be porous to enable rapid nutrient and oxygen transfer while providing a three-dimensional (3D) microenvironment for the encapsulated cells. This dual characteristic can be achieved by fabrication of porous hydrogels that contain encapsulated cells. In this work, we developed a simple method that allows cell encapsulation and pore generation inside alginate hydrogels simultaneously. Gelatin beads of 150-300 μm diameter were used as a sacrificial porogen for generating pores within cell-laden hydrogels. Gelation of gelatin at low temperature (4 0 C) was used to form beads without chemical crosslinking and their subsequent dissolution after cell encapsulation led to generation of pores within cell-laden hydrogels. The pore size and porosity of the scaffolds were controlled by the gelatin bead size and their volume ratio, respectively. Fabricated hydrogels were characterized for their internal microarchitecture, mechanical properties and permeability. Hydrogels exhibited a high degree of porosity with increasing gelatin bead content in contrast to nonporous alginate hydrogel. Furthermore, permeability increased by two to three orders while compressive modulus decreased with increasing porosity of the scaffolds. Application of these scaffolds for tissue engineering was tested by encapsulation of hepatocarcinoma cell line (HepG2). All the scaffolds showed similar cell viability; however, cell proliferation was enhanced under porous conditions. Furthermore, porous alginate hydrogels resulted in formation of larger spheroids and higher albumin secretion compared to nonporous conditions. These data suggest that porous alginate hydrogels may have provided a better environment for cell proliferation and albumin production. This may be due to the enhanced mass transfer of nutrients, oxygen and waste removal, which is potentially beneficial for tissue engineering and regenerative medicine applications.

Fabrication of copper-selective PVC membrane electrode based on newly synthesized copper complex of Schiff base as carrier

Directory of Open Access Journals (Sweden)

Sulekh Chandra

2016-09-01

Full Text Available The newly synthesized copper(II complex of Schiff base p-hydroxyacetophenone semicarbazone was explored as neutral ionophore for the fabrication of poly(vinylchloride (PVC based membrane electrode selective to Cu(II ions. The electrode shows a Nernstian slope of 29.8 ± 0.3 mV/decade with improved linear range of 1.8 × 10−7 to 1.0 × 10−1 M, comparatively lower detection limit 5.7 × 10−8 M between pH range of 2.0–8.0, giving a relatively fast response within 5s and can be used for at least 16 weeks without any divergence in potential. The selectivity coefficient was calculated using the fixed interference method (FIM. The electrode can also be used in partially non-aqueous media having up to 25% (v/v methanol, ethanol or acetone content with no significant change in the value of slope or working concentration range. It was successfully applied for the direct determination of copper content in water and tea samples with satisfactory results. The electrode has been used in the potentiometric titration of Cu2+ with EDTA.

A Flexible Ascorbic Acid Fuel Cell with a Microchannel Fabricated using MEMS Techniques

Science.gov (United States)

Mogi, Hiroshi; Fukushi, Yudai; Koide, Syohei; Sano, Ryohei; Sasaki, Tsubasa; Nishioka, Yasushiro

2013-12-01

We fabricated a miniature ascorbic acid fuel cells equipped with a microchannel for the circulation of ascorbic acid (AA) solution using micro electronic mechanical system techniques. The fuel cell was fabricated on a flexible polyimide substrate, and its porous carbon-coated aluminium (Al) electrodes of 2.8 mm in width and 11 mm in length were formed using photolithography and screen-printing techniques. The porous carbon was deposited by screen-printing of carbon-black ink on the Al electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the cathode surface. The microchannel with a depth of 200 μm was fabricated using a hot-embossing technique. A maximum power of 0.60 μW at 0.58 V that corresponds to a power density of 1.83 μW/cm2 was realized by introducing a 200 mM concentrated AA solution at room temperature.

Performance of Dye-Sensitized Solar Cells (DSSCs) Fabricated with Zinc Oxide (ZnO) Nanpowders and Nanorods

Science.gov (United States)

Chatterjee, Suman

2018-03-01

Due to their high efficiencies, along with lower production costs, many researchers are working on dye-sensitized solar cells (DSSCs) over last few decades as a substitute technology for nonconventional energy. Nanostructured ZnO has got many interesting properties such as wide band gap, large exciton binding energy, good exciton stability, and high breakdown strength, which are applicable as DSSC electrodes. This present work compares the device properties of DSSC fabricated using ZnO nanorods on a ZnO film and ZnO nanopowders. Different types of ZnO photoanode and dye combinations are used to study the stability and photovoltaic properties of the DSSC cell. The photovoltaic properties of the ZnO-based DSSC samples were systematically investigated. The photovoltaic properties of fabricated cell obtained are discussed in the light of band structure and density of states of different types of ZnO nanolayers. The ZnO nanorods fabricated through the sol-gel route have more uniform thickness resulting in enhanced photovoltaic properties of the fabricated device.

Fabrication and characterization of organic solar cells using metal complex of phthalocyanines

Energy Technology Data Exchange (ETDEWEB)

Kida, Tomoyasu, E-mail: suzuki@mat.usp.ac.jp; Suzuki, Atsushi, E-mail: suzuki@mat.usp.ac.jp; Akiyama, Tsuyoshi, E-mail: suzuki@mat.usp.ac.jp; Oku, Takeo, E-mail: suzuki@mat.usp.ac.jp [Department of Materials Science, The University of Shiga Prefecture 2500 Hassaka, Hikone, Shiga 522-8533 (Japan)

2015-02-27

Fabrication and characterization of organic solar cells using shuttle-cock-type phthalocyanines were carried out. Photovoltaic properties of the solar cells with inverted structures were investigated by current density-voltage characteristics. Effects of phase transition between H and J aggregates on the photovoltaic and optical properties were investigated. The photovoltaic mechanisms, energy levels and band gap of active layers were discussed.

Fabrication of Affordable and Sustainable Solar Cells Using NiO/TiO2 P-N Heterojunction

Directory of Open Access Journals (Sweden)

Kingsley O. Ukoba

2018-01-01

Full Text Available The need for affordable, clean, efficient, and sustainable solar cells informed this study. Metal oxide TiO2/NiO heterojunction solar cells were fabricated using the spray pyrolysis technique. The optoelectronic properties of the heterojunction were determined. The fabricated solar cells exhibit a short-circuit current of 16.8 mA, open-circuit voltage of 350 mV, fill factor of 0.39, and conversion efficiency of 2.30% under 100 mW/cm2 illumination. This study will help advance the course for the development of low-cost, environmentally friendly, and sustainable solar cell materials from metal oxides.

Dye-sensitized solar cells fabricated with black raspberry, black carrot and rosella juice

Science.gov (United States)

Tekerek, S.; Kudret, A.; Alver, Ü.

2011-10-01

In this work, dye sensitized solar cells (DSSC's) were constructed from black raspberry ( Rubus Ideaus), black carrot ( Daucuscarota L.) and rosella juice ( Hibiscus Sabdariffa L.). In order to fabricate a DSSC the fluorine-doped tin (IV) oxide (FTO) thin films obtained by using spray pyrolysis technique were used as a substrate. TiO2 films on FTO layers were prepared by doctor-blading technique. Platinum-coated counter electrode and liquid Iodide/Iodine electrolyte solution were used to fabricate DSSC's. The efficiencies of solar cells produced with black carrot, rosella and black raspberry juice were calculated as 0.25%, 0.16% and 0.16% respectively, under a sunny day in Kahramanmaraş-Turkey.

Research on fabrication technology for thin film solar cells for practical use. Technological development for qualitative improvement (development of fabrication technology of thin film polycrystalline Si solar cell); Usumaku taiyo denchi seizo gijutsu no jitsuyoka kenkyu. Kohinshitsuka gijutsu (usumaku takessho silicon kei taiyo denchi seizo no gijutsu kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

Tatsuta, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

1994-12-01

This paper reports the study results on the fabrication technology of thin film polycrystalline Si solar cells in fiscal 1994. (1) On the fabrication technology of high-quality Si thin films, the new equipment was studied which allows uniform stable melting recrystallization over a large area. The new equipment adopted a heating method based on RTP system, and is now under adjustment. (2) On the fabrication technology of light/carrier confinement structure, degradation of hydrogen-treated thin film Si solar cells by light irradiation was examined. As a result, since any characteristic degradation was not found even by long time light irradiation, the high quality of the cells was confirmed regardless of hydrogen-treatment. Fabrication of stable reproducible fine texture structure became possible by using fabrication technology of light confinement structure by texture treatment of cell surfaces. (3) On low-cost process technology, design by VEST process, estimation of cell characteristics by simulation, and characteristics of prototype cells were reported. 33 figs., 1 tab.

Improved Laser Manipulation for On-chip Fabricated Microstructures Based on Solution Replacement and Its Application in Single Cell Analysis

Directory of Open Access Journals (Sweden)

Tao Yue

2014-02-01

Full Text Available In this paper, we present the fabrication and assembly of microstructures inside a microfluidic device based on a photocrosslinkable resin and optical tweezers. We also report a method of solution replacement inside the microfluidic channel in order to improve the manipulation performance and apply the assembled microstructures for single cell cultivation. By the illumination of patterned ultraviolet (UV through a microscope, microstructures of arbitrary shape were fabricated by the photocrosslinkable resin inside a microfluidic channel. Based on the microfluidic channel with both glass and polydimethylsiloxane (PDMS surfaces, immovable and movable microstructures were fabricated and manipulated. The microstructures were fabricated at the desired places and manipulated by the optical tweezers. A rotational microstructure including a microgear and a rotation axis was assembled and rotated in demonstrating this technique. The improved laser manipulation of microstructures was achieved based on the on-chip solution replacement method. The manipulation speed of the microstructures increased when the viscosity of the solvent decreased. The movement efficiency of the fabricated microstructures inside the lower viscosity solvent was evaluated and compared with those microstructures inside the former high viscosity solvent. A novel cell cage was fabricated and the cultivation of a single yeast cell (w303 was demonstrated in the cell cage, inside the microfluidic device.

Production of Multiple Growth Factors by a Newly Established Human Thyroid Carcinoma Cell Line

Science.gov (United States)

Yoshida, Yataro; Ohashi, Kensaku; Sano, Emiko; Kobayashi, Hisataka; Endo, Keigo; Naruto, Masanobu; Nakamura, Toru

1992-01-01

A multiple growth factor‐producing tumor cell line (NIM‐1) was newly established from a patient with thyroid cancer and remarkable neutrophilia. NIM‐1 cells also caused severe neutrophilia in nude mice bearing tumors. NIM‐1‐conditioned medium (NIM‐1CM) contained activities that supported not only granulocyte, macrophage and eosinophil colony formation of human bone marrow cells but also the growth of colony‐stimulating factor (CSF)‐dependent cell lines, NFS60‐KX and TF‐1. Northern blot hybridization analysis revealed the constitutive expression of granulocyte‐CSF (G‐CSF), granulocyte/macrophage‐CSF (GM‐CSF) and interleukin(IL)‐6 mRNAs in NIM‐1 cells. Enzyme‐linked immunosorbent assays (ELISA) using NIM‐1CM also confirmed the production of IL‐la and a small amount of IL‐1β besides G‐CSF, GM‐CSF and IL‐6 in NIM‐1 cells. In addition, unexpected production of IL‐11 in NIM‐1 cells was detected by northern blot hybridization analysis and by bioassay using an IL‐11‐dependent cell line. Therefore, NIM‐1 cell line is shown to produce multiple cytokines including potentially megakaryopoietic growth factors such as GM‐CSF, IL‐6 and IL‐11. PMID:1372885

Wire Array Solar Cells: Fabrication and Photoelectrochemical Studies

Science.gov (United States)

Spurgeon, Joshua Michael

Despite demand for clean energy to reduce our addiction to fossil fuels, the price of these technologies relative to oil and coal has prevented their widespread implementation. Solar energy has enormous potential as a carbon-free resource but is several times the cost of coal-produced electricity, largely because photovoltaics of practical efficiency require high-quality, pure semiconductor materials. To produce current in a planar junction solar cell, an electron or hole generated deep within the material must travel all the way to the junction without recombining. Radial junction, wire array solar cells, however, have the potential to decouple the directions of light absorption and charge-carrier collection so that a semiconductor with a minority-carrier diffusion length shorter than its absorption depth (i.e., a lower quality, potentially cheaper material) can effectively produce current. The axial dimension of the wires is long enough for sufficient optical absorption while the charge-carriers are collected along the shorter radial dimension in a massively parallel array. This thesis explores the wire array solar cell design by developing potentially low-cost fabrication methods and investigating the energy-conversion properties of the arrays in photoelectrochemical cells. The concept was initially investigated with Cd(Se, Te) rod arrays; however, Si was the primary focus of wire array research because its semiconductor properties make low-quality Si an ideal candidate for improvement in a radial geometry. Fabrication routes for Si wire arrays were explored, including the vapor-liquid-solid growth of wires using SiCl4. Uniform, vertically aligned Si wires were demonstrated in a process that permits control of the wire radius, length, and spacing. A technique was developed to transfer these wire arrays into a low-cost, flexible polymer film, and grow multiple subsequent arrays using a single Si(111) substrate. Photoelectrochemical measurements on Si wire array

Silicon Solar Cell Process Development, Fabrication and Analysis, Phase 1

Science.gov (United States)

Yoo, H. I.; Iles, P. A.; Tanner, D. P.

1979-01-01

Solar cells from RTR ribbons, EFG (RF and RH) ribbons, dendritic webs, Silso wafers, cast silicon by HEM, silicon on ceramic, and continuous Czochralski ingots were fabricated using a standard process typical of those used currently in the silicon solar cell industry. Back surface field (BSF) processing and other process modifications were included to give preliminary indications of possible improved performance. The parameters measured included open circuit voltage, short circuit current, curve fill factor, and conversion efficiency (all taken under AM0 illumination). Also measured for typical cells were spectral response, dark I-V characteristics, minority carrier diffusion length, and photoresponse by fine light spot scanning. the results were compared to the properties of cells made from conventional single crystalline Czochralski silicon with an emphasis on statistical evaluation. Limited efforts were made to identify growth defects which will influence solar cell performance.

Large-scale Roll-to-Roll Fabrication of Organic Solar Cells for Energy Production

DEFF Research Database (Denmark)

Hösel, Markus

intelligent connection of single cells that should involve as less as possible manual processes such as wiring or soldering. The problem was solved by serially connecting thousands of single cells entirely during the R2R processing by printing thin-film silver conductors. High voltage networks require only...... be produced cheaply and very fast from solution with printing processes. The current research all around the world is still focused on lab-scale sized devices « cm2, ITO-glass substrates, and spin coating as the main fabrication method. These OPV devices are far from any practical application although record...... substrates and ITO-free transparent conductive electrodes made from special designed flexo printed silver grids, rotary screen printed PEDOT:PSS, and slot-die coated ZnO (= Flextrode). The organic solar cell was fabricated by slot-die coating a light absorbing photoactive layer (e. g. P3HT:PCBM) on top...

Physicochemical properties of newly developed bioactive glass cement and its effects on various cells.

Science.gov (United States)

Washio, Ayako; Nakagawa, Aika; Nishihara, Tatsuji; Maeda, Hidefumi; Kitamura, Chiaki

2015-02-01

Biomaterials used in dental treatments are expected to have favorable properties such as biocompatibility and an ability to induce tissue formation in dental pulp and periapical tissue, as well as sealing to block external stimuli. Bioactive glasses have been applied in bone engineering, but rarely applied in the field of dentistry. In the present study, bioactive glass cement for dental treatment was developed, and then its physicochemical properties and effects on cell responses were analyzed. To clarify the physicochemical attributes of the cement, field emission scanning electron microscopy, X-ray diffraction, and pH measurement were carried out. Cell attachment, morphology, and viability to the cement were also examined to clarify the effects of the cement on odontoblast-like cells (KN-3 cells), osteoblastic cells (MC3T3-E1 cells), human periodontal ligament stem/progenitor cells and neuro-differentiative cells (PC-12 cells). Hydroxyapatite-like precipitation was formed on the surface of the hardened cement and the pH level changed from pH10 to pH9, then stabilized in simulate body fluid. The cement had no cytotxic effects on these cells, and particulary induced process elongation of PC-12 cells. Our results suggest that the newly developed bioactive glass cement have capability of the application in dental procedures as bioactive cement. © 2014 Wiley Periodicals, Inc.

Photoexcitation dynamics in solution-processed formamidinium lead iodide perovskite thin films for solar cell applications

NARCIS (Netherlands)

Fang, Hong-Hua; Wang, Feng; Adjokatse, Sampson; Zhao, Ni; Even, Jacky; Loi, Maria Antonietta

Formamidinium lead iodide (FAPbI(3)) is a newly developed hybrid perovskite that potentially can be used in high-efficiency solution-processed solar cells. Here, the temperature-dependent dynamic optical properties of three types of FAPbI(3) perovskite films (fabricated using three different

Fabrication and Characterization of Organic Photovoltaic Cell using Keithley 2400 SMU for efficient solar cell

Science.gov (United States)

Hafeez, Hafeez Y.; Iro, Zaharaddeen S.; Adam, Bala I.; Mohammed, J.

2018-04-01

An organic solar cell device or organic photovoltaic cell (OPV) is a class of solar cell that uses conductive organic polymers or small organic molecules for light absorption and charge transport. In this study, we fabricate and characterize an organic photovoltaic cell device and estimated important parameters of the device such as Open Circuit Voltage Voc of 0.28V, Short-Circuit Current Isc of 4.0 × 10-5 A, Maximum Power Pmax of 2.4 × 10-6 W, Fill Factor of 0.214 and the energy conversion efficiency of η=0.00239% were tested using Keithley 2400,source meter under A.M 1.5 (1000/m2) illumination from a Newport Class A solar simulator. Also the I-V characteristics for OPV were drawn.

A three-dimensional hierarchical collagen scaffold fabricated by a combined solid freeform fabrication (SFF) and electrospinning process to enhance mesenchymal stem cell (MSC) proliferation

International Nuclear Information System (INIS)

Ahn, SeungHyun; Kim, GeunHyung; Koh, Young Ho

2010-01-01

Collagen has the advantage of being very similar to macromolecular substances that can be recognized and metabolized in the biological environment. Although the natural material has superior property for this purpose, its use to fabricate reproducible and pore-structure-controlled 3D structures, which are designed to allow the entry of sufficient cells and the easy diffusion of nutrients, has been limited due to its low processability. Here, we propose a hybrid technology that combines a cryogenic plotting system with an electrospinning process. Using this technique, an easily pore-size-controllable hierarchical 3D scaffold consisting of micro-sized highly porous collagen strands and micro/nano-sized collagen fibers was fabricated. The pore structure of the collagen scaffold was controlled by the collagen micro/nanofibers, which were layered in the scaffold. The hierarchical scaffolds were characterized with respect to initial cell attachment and proliferation of bone marrow-derived mesenchymal stem cells within the scaffolds. The hierarchical scaffold exhibited incredibly enhanced initial cell attachment and cell compactness between pores of the plotted scaffold relative to the normally designed 3D collagen scaffold.

Using injection molding and reversible bonding for easy fabrication of magnetic cell trapping and sorting devices

Energy Technology Data Exchange (ETDEWEB)

Royet, David; Hériveaux, Yoann; Marchalot, Julien; Scorretti, Riccardo [Univ Lyon, ECL, UCB Lyon1, CNRS, Ampere, F-69134 Ecully (France); Dias, André; Dempsey, Nora M. [Univ. Grenoble Alpes - CNRS, Inst Neel, F-38042 Grenoble (France); Bonfim, Marlio [Universidade Federal do Paraná, DELT, Curitiba (Brazil); Simonet, Pascal; Frénéa-Robin, Marie [Univ Lyon, ECL, UCB Lyon1, CNRS, Ampere, F-69134 Ecully (France)

2017-04-01

Magnetism and microfluidics are two key elements for the development of inexpensive and reliable tools dedicated to high-throughput biological analysis and providing a large panel of applications in domains ranging from fundamental biology to medical diagnostics. In this work, we introduce a simple protocol, relying on injection molding and reversible bonding for fabrication of magnetic cell trapping and sorting devices using only standard soft-lithography equipment. Magnetic strips or grids made of Polydimethylsiloxane (PDMS) doped with hard (NdFeB) or soft (carbonyl iron) magnetic powders were integrated at the bottom of whole PDMS chips. Preliminary results show the effective deviation/trapping of magnetic beads or magnetically-labeled bacteria as the sample flows through the microchannel, proving the potential of this rapid prototyping approach for easy fabrication of magnetic cell sorters. - Highlights: • Soft and hard magnetic PDMS composites were microstructured by injection molding. • Tunable or autonomous magnetic microdevices can be fabricated using this approach. • Continuous-flow bacterial cell trapping and deviation were demonstrated.

Using injection molding and reversible bonding for easy fabrication of magnetic cell trapping and sorting devices

International Nuclear Information System (INIS)

Royet, David; Hériveaux, Yoann; Marchalot, Julien; Scorretti, Riccardo; Dias, André; Dempsey, Nora M.; Bonfim, Marlio; Simonet, Pascal; Frénéa-Robin, Marie

2017-01-01

Magnetism and microfluidics are two key elements for the development of inexpensive and reliable tools dedicated to high-throughput biological analysis and providing a large panel of applications in domains ranging from fundamental biology to medical diagnostics. In this work, we introduce a simple protocol, relying on injection molding and reversible bonding for fabrication of magnetic cell trapping and sorting devices using only standard soft-lithography equipment. Magnetic strips or grids made of Polydimethylsiloxane (PDMS) doped with hard (NdFeB) or soft (carbonyl iron) magnetic powders were integrated at the bottom of whole PDMS chips. Preliminary results show the effective deviation/trapping of magnetic beads or magnetically-labeled bacteria as the sample flows through the microchannel, proving the potential of this rapid prototyping approach for easy fabrication of magnetic cell sorters. - Highlights: • Soft and hard magnetic PDMS composites were microstructured by injection molding. • Tunable or autonomous magnetic microdevices can be fabricated using this approach. • Continuous-flow bacterial cell trapping and deviation were demonstrated.

Fabrication of 20.19% Efficient Single-Crystalline Silicon Solar Cell with Inverted Pyramid Microstructure.

Science.gov (United States)

Zhang, Chunyang; Chen, Lingzhi; Zhu, Yingjie; Guan, Zisheng

2018-04-03

This paper reports inverted pyramid microstructure-based single-crystalline silicon (sc-Si) solar cell with a conversion efficiency up to 20.19% in standard size of 156.75 × 156.75 mm 2 . The inverted pyramid microstructures were fabricated jointly by metal-assisted chemical etching process (MACE) with ultra-low concentration of silver ions and optimized alkaline anisotropic texturing process. And the inverted pyramid sizes were controlled by changing the parameters in both MACE and alkaline anisotropic texturing. Regarding passivation efficiency, the textured sc-Si with normal reflectivity of 9.2% and inverted pyramid size of 1 μm was used to fabricate solar cells. The best batch of solar cells showed a 0.19% higher of conversion efficiency and a 0.22 mA cm -2 improvement in short-circuit current density, and the excellent photoelectric property surpasses that of the same structure solar cell reported before. This technology shows great potential to be an alternative for large-scale production of high efficient sc-Si solar cells in the future.

Comparative Survival in Patients With Postresection Recurrent Versus Newly Diagnosed Non-Small-Cell Lung Cancer Treated With Radiotherapy

International Nuclear Information System (INIS)

Cai Xuwei; Xu Luying; Wang Li; Hayman, James A.; Chang, Andrew C.; Pickens, Allan; Cease, Kemp B.; Orringer, Mark B.; Kong, F.-M.

2010-01-01

Purpose: To compare the survival of postresection recurrent vs. newly diagnosed non-small-cell lung cancer (NSCLC) patients treated with radiotherapy or chemoradiotherapy. Methods and Materials: The study population consisted of 661 consecutive patients with NSCLC registered in the radiation oncology databases at two medical centers in the United States between 1992 and 2004. Of the 661 patients, 54 had postresection recurrent NSCLC and 607 had newly diagnosed NSCLC. Kaplan-Meier and Cox regression models were used for the survival analyses. Results: The distribution of relevant clinical factors between these two groups was similar. The median survival time and 5-year overall survival rates were 19.8 months (95% confidence interval [CI], 13.9-25.7) and 14.8% (95% confidence interval, 5.4-24.2%) vs. 12.2 months (95% CI, 10.8-13.6) and 11.0% (95% CI, 8.5-13.5%) for recurrent vs. newly diagnosed patients, respectively (p = .037). For Stage I-III patients, no significant difference was observed in the 5-year overall survival (p = .297) or progression-free survival (p = .935) between recurrent and newly diagnosed patients. For the 46 patients with Stage I-III recurrent disease, multivariate analysis showed that chemotherapy was a significant prognostic factor for 5-year progression-free survival (hazard ratio, 0.45; 95% CI, 0.224-0.914; p = .027). Conclusion: Our institutional data have shown that patients with postresection recurrent NSCLC achieved survival comparable to that of newly diagnosed NSCLC patients when they were both treated with radiotherapy or chemoradiotherapy. These findings suggest that patients with postresection recurrent NSCLC should be treated as aggressively as those with newly diagnosed disease.

Effect of alkali treatment on the morphology and tensile properties of Cordia dichotoma fabric/polycarbonate composites

CSIR Research Space (South Africa)

Jayaramudu, J

2013-05-01

Full Text Available The newly identified natural fabric from the tree of Cordia dichotoma was coated with polycarbonate. Tensile parameters, such as, tensile strength, Young’s modulus, and percentage of elongation at the break of the fabrics were determined using a...

FABRICE process for the refrabrication of experimental pins in a hot cell, from pins pre-irradiated in power reactors

International Nuclear Information System (INIS)

Vignesoult, N.; Atabek, R.; Ducas, S.

1982-06-01

The Fabrice ''hot cell refabrication'' process for small pins from very long irradiated fuel elements was developed at the CEA to allow parametric studies of the irradiation behavior of pins from nuclear power plants. Since this operation required complete assurance of the validity of the process, qualification of the fabrication was performed on test pins, refabricated in the hot cell, as well as irradiation qualification. The latter qualification was intended to demonstrate that, in identical experimental irradiation conditions, the refabricated Fabrice pins behaved in the same way as whole pins with the same initial characteristics. This qualification of the Fabrice process, dealing with more than twenty pins at different burnups, showed that fabrication did not alter: the inherent characteristics of the sampled fuel element and the irradiation behavior of the sampled fuel element [fr

The Impact of Graphene on the Fabrication of Thin Film Solar Cells: Current Status and Future Prospects

Directory of Open Access Journals (Sweden)

Zhengqi Shi

2017-12-01

Full Text Available Commercial solar cells have a power conversion efficiency (PCE in the range of 10–22% with different light absorbers. Graphene, with demonstrated unique structural, physical, and electrical properties, is expected to bring the positive effects on the development of thin film solar cells. Investigations have been carried out to understand whether graphene can be used as a front and back contacts and active interfacial layer in solar cell fabrication. In this review, the current progress of this research is analyzed, starting from the graphene and graphene-based Schottky diode. Also, the discussion was focused on the progress of graphene-incorporated thin film solar cells that were fabricated with different light absorbers, in particular, the synthesis, fabrication, and characterization of devices. The effect of doping and layer thickness of graphene on PCE was also included. Currently, the PCE of graphene-incorporated bulk-heterojunction devices have enhanced in the range of 0.5–3%. However, device durability and cost-effectiveness are also the challenging factors for commercial production of graphene-incorporated solar cells. In addition to the application of graphene, graphene oxides have been also used in perovskite solar cells. The current needs and likely future investigations for graphene-incorporated solar cells are also discussed.

Low temperature fabrication of perovskite solar cells with TiO{sub 2} nanoparticle layers

Energy Technology Data Exchange (ETDEWEB)

Kanayama, Masato; Oku, Takeo, E-mail: oku@mat.usp.ac.jp; Suzuki, Atsushi [Department of Materials Science, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga 522-8533 (Japan); Yamada, Masahiro; Sakamoto, Hiroki [Energy Technology Laboratories, Osaka Gas Co., Ltd., Osaka 554-0051 (Japan); Minami, Satoshi; Kohno, Kazufumi [Frontier Materials Laboratories, Osaka Gas Chemicals Co., Ltd., Osaka 554-0051 (Japan)

2016-02-01

TiO{sub 2}/CH{sub 3}NH{sub 3}PbI{sub 3}-based photovoltaic devices were fabricated by a spin-coating method using a mixture solution. TiO{sub 2} require high-temperature processing to achieve suitably high carrier mobility. TiO{sub 2} electron transport layers and TiO{sub 2} scaffold layers for the perovskite were fabricated from TiO{sub 2} nanoparticles with different grain sizes. The photovoltaic properties and microstructures of solar cells were characterized. Nanoparticle sizes of these TiO{sub 2} were 23 nm and 3 nm and the performance of solar cells was improved by combination of two TiO{sub 2} nanoparticles.

Manipulation of radicals and ions in LFICP-aided fabrication of high efficiency solar cells

International Nuclear Information System (INIS)

Xu, S.

2013-01-01

In this talk, we report on the development and diagnostics of low frequency inductively coupled plasma (LFICP) reactor for fabrication of high efficiency silicon solar cells. Chemically active, thermally non-equilibrium plasma possess unique advantages for manipulation of plasma-generated radicals/ions and overall control of growth and self-organization processes that are crucial for fabrication of photovoltaic materials and solar cells. In low frequency inductively coupled plasmas, generation, selection and control of densities and fluxes of the radicals and ions can easily be controlled by the electron energy distributions and other plasma parameters. The electric field and thermal forces guide selective delivery of the radicals to the surface. Specific substrate activation and temperature determine the ion/heat fluxes from the gas phase to the charged surfaces. Detailed discussion includes the inter-connection between in-situ plasma diagnostics (Optical Emission Spectroscopy, Langmuir Probe diagnostics, and Quadruple Mass Spectrometry) and ex-situ material characterization (XRD, Raman, FTIR EDX, UV/Vis, SEM, Hall-effect and others). Special emphasis is paid to the identification and control strategies of the plasma-generated radicals/ions existed in both the ionized gas phase and on the deposition surfaces. We will show how radicals and ions can be manipulated to meet the structural, optical and electronic requirements for high efficiency photovoltaic cells. Solar cell fabricated by the LFICP plasma exhibits an extraordinarily photovoltaic performance with energy conversion efficiency exceeding 18%. (author)

Concise Review: Bioprinting of Stem Cells for Transplantable Tissue Fabrication.

Science.gov (United States)

Leberfinger, Ashley N; Ravnic, Dino J; Dhawan, Aman; Ozbolat, Ibrahim T

2017-10-01

Bioprinting is a quickly progressing technology, which holds the potential to generate replacement tissues and organs. Stem cells offer several advantages over differentiated cells for use as starting materials, including the potential for autologous tissue and differentiation into multiple cell lines. The three most commonly used stem cells are embryonic, induced pluripotent, and adult stem cells. Cells are combined with various natural and synthetic materials to form bioinks, which are used to fabricate scaffold-based or scaffold-free constructs. Computer aided design technology is combined with various bioprinting modalities including droplet-, extrusion-, or laser-based bioprinting to create tissue constructs. Each bioink and modality has its own advantages and disadvantages. Various materials and techniques are combined to maximize the benefits. Researchers have been successful in bioprinting cartilage, bone, cardiac, nervous, liver, and vascular tissues. However, a major limitation to clinical translation is building large-scale vascularized constructs. Many challenges must be overcome before this technology is used routinely in a clinical setting. Stem Cells Translational Medicine 2017;6:1940-1948. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Guided-mode resonant solar cells and flat-top reflectors: Analysis, design, fabrication and characterization

Science.gov (United States)

Khaleque, Tanzina

This dissertation addresses the guided-mode resonance (GMR) effect and its applications. In particular, this study presents theoretical analysis and corresponding experiments on two important GMR devices that can be broadly described as GMR-enabled thin-film solar cells and flat-top reflectors. The GMR-induced enhanced absorption of input light is observed and quantified in a fabricated nano-patterned amorphous silicon (a-Si) thin-film. Compared to a reference homogeneous thin-film of a-Si, approximately 50% integrated absorbance enhancement is achieved in the patterned structure. This result motivates the application of these resonance effects in thin-film solar cells where enhanced solar absorbance is a crucial requirement. Light trapping in thin-film solar cells through the GMR effect is theoretically explained and experimentally demonstrated. Nano-patterned solar cells with 300-nm periods in one-dimensional gratings are designed, fabricated, and characterized. Compared to a planar reference solar cell, around 35% integrated absorption enhancement is observed over the 450--750-nm wavelength range. This light-management method results in enhanced short-circuit current density of 14.8 mA/cm 2, which is a ˜40% improvement over planar solar cells. The experimental demonstration proves the potential of simple and well-designed guided-mode resonant features in thin-film solar cells. In order to complement the research on GMR thin-film solar cells, a single-step, low-cost fabrication method for generating resonant nano-grating patterns on poly-methyl-methacrylate (PMMA; plexiglas) substrates using thermal nano-imprint lithography is reported. The imprinted structures of both one and two dimensional nano-grating patterns with 300 nm period are fabricated. Thin films of indium-tin-oxide and silicon are deposited over patterned substrates and the absorbance of the films is measured. Around 25% and 45% integrated optical absorbance enhancement is observed over the 450-nm

Multiwalled carbon nanotube coated polyester fabric as textile based flexible counter electrode for dye sensitized solar cell.

Science.gov (United States)

Arbab, Alvira Ayoub; Sun, Kyung Chul; Sahito, Iftikhar Ali; Qadir, Muhammad Bilal; Jeong, Sung Hoon

2015-05-21

Textile wearable electronics offers the combined advantages of both electronics and textile characteristics. The essential properties of these flexible electronics such as lightweight, stretchable, and wearable power sources are in strong demand. Here, we have developed a facile route to fabricate multi walled carbon nanotube (MWCNT) coated polyester fabric as a flexible counter electrode (CE) for dye sensitized solar cells (DSSCs). A variety of MWCNT and enzymes with different structures were used to generate individual enzyme-dispersed MWCNT (E-MWCNT) suspensions by non-covalent functionalization. A highly concentrated colloidal suspension of E-MWCNT was deposited on polyester fabric via a simple tape casting method using an air drying technique. In view of the E-MWCNT coating, the surface structure is represented by topologically randomly assembled tubular graphene units. This surface morphology has a high density of colloidal edge states and oxygen-containing surface groups which execute multiple catalytic sites for iodide reduction. A highly conductive E-MWCNT coated fabric electrode with a surface resistance of 15 Ω sq(-1) demonstrated 5.69% power conversion efficiency (PCE) when used as a flexible CE for DSSCs. High photo voltaic performance of our suggested system of E-MWCNT fabric-based DSSCs is associated with high sheet conductivity, low charge transfer resistance (RCT), and excellent electro catalytic activity (ECA). Such a conductive fabric demonstrated stable conductivity against bending cycles and strong mechanical adhesion of E-MWCNT on polyester fabric. Moreover, the polyester fabric is hydrophobic and, therefore, has good sealing capacity and retains the polymer gel electrolyte without seepage. This facile E-MWCNT fabric CE configuration provides a concrete fundamental background towards the development of textile-integrated solar cells.

Demonstration of glucose-6-phosphate dehydrogenase in rat Kupffer cells by a newly-developed ultrastructural enzyme-cytochemistry

Directory of Open Access Journals (Sweden)

S Matsubara

2009-06-01

Full Text Available Although various tissue macrophages possess high glucose- 6-phosphate dehydrogenase (G6PD activity, which is reported to be closely associated with their phagocytotic/bactericidal function, the fine subcellular localization of this enzyme in liver resident macrophages (Kupffer cells has not been determined.We have investigated the subcellular localization of G6PD in Kupffer cells in rat liver, using a newly developed enzyme-cytochemical (copper-ferrocyanide method. Electron-dense precipitates indicating G6PD activity were clearly visible in the cytoplasm and on the cytosolic side of the endoplasmic reticulum of Kupffer cells. Cytochemical controls ensured specific detection of the enzymatic activity. Rat Kupffer cells abundantly possessed enzyme-cytochemically detectable G6PD activity. Kupffer cell G6PD may play a role in liver defense by delivering NADPH to NADPH-dependent enzymes. G6PD enzyme-cytochemistry may be a useful tool for the study of Kupffer cell functions.

Fabrication of organic-inorganic perovskite thin films for planar solar cells via pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Liang, Yangang; Zhang, Xiaohang; Gong, Yunhui; Shin, Jongmoon; Wachsman, Eric D.; Takeuchi, Ichiro, E-mail: takeuchi@umd.edu [Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20740 (United States); Yao, Yangyi; Hsu, Wei-Lun; Dagenais, Mario [Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20740 (United States)

2016-01-15

We report on fabrication of organic-inorganic perovskite thin films using a hybrid method consisting of pulsed laser deposition (PLD) of lead iodide and spin-coating of methylammonium iodide. Smooth and highly crystalline CH{sub 3}NH{sub 3}PbI{sub 3} thin films have been fabricated on silicon and glass coated substrates with fluorine doped tin oxide using this PLD-based hybrid method. Planar perovskite solar cells with an inverted structure have been successfully fabricated using the perovskite films. Because of its versatility, the PLD-based hybrid fabrication method not only provides an easy and precise control of the thickness of the perovskite thin films, but also offers a straightforward platform for studying the potential feasibility in using other metal halides and organic salts for formation of the organic-inorganic perovskite structure.

Fabrication of organic-inorganic perovskite thin films for planar solar cells via pulsed laser deposition

Directory of Open Access Journals (Sweden)

Yangang Liang

2016-01-01

Full Text Available We report on fabrication of organic-inorganic perovskite thin films using a hybrid method consisting of pulsed laser deposition (PLD of lead iodide and spin-coating of methylammonium iodide. Smooth and highly crystalline CH3NH3PbI3 thin films have been fabricated on silicon and glass coated substrates with fluorine doped tin oxide using this PLD-based hybrid method. Planar perovskite solar cells with an inverted structure have been successfully fabricated using the perovskite films. Because of its versatility, the PLD-based hybrid fabrication method not only provides an easy and precise control of the thickness of the perovskite thin films, but also offers a straightforward platform for studying the potential feasibility in using other metal halides and organic salts for formation of the organic-inorganic perovskite structure.

Fabrication of Biomolecule Microarrays for Cell Immobilization Using Automated Microcontact Printing.

Science.gov (United States)

Foncy, Julie; Estève, Aurore; Degache, Amélie; Colin, Camille; Cau, Jean Christophe; Malaquin, Laurent; Vieu, Christophe; Trévisiol, Emmanuelle

2018-01-01

Biomolecule microarrays are generally produced by conventional microarrayer, i.e., by contact or inkjet printing. Microcontact printing represents an alternative way of deposition of biomolecules on solid supports but even if various biomolecules have been successfully microcontact printed, the production of biomolecule microarrays in routine by microcontact printing remains a challenging task and needs an effective, fast, robust, and low-cost automation process. Here, we describe the production of biomolecule microarrays composed of extracellular matrix protein for the fabrication of cell microarrays by using an automated microcontact printing device. Large scale cell microarrays can be reproducibly obtained by this method.

Capacitor-less memory cell fabricated on nano-scale strained Si on a relaxed SiGe layer-on-insulator

International Nuclear Information System (INIS)

Kim, Tae-Hyun; Park, Jea-Gun

2013-01-01

We investigated the combined effect of the strained Si channel and hole confinement on the memory margin enhancement for a capacitor-less memory cell fabricated on nano-scale strained Si on a relaxed SiGe layer-on-insulator (ε-Si SGOI). The memory margin for the ε-Si SGOI capacitor-less memory cell was higher than that of the memory cell fabricated on an unstrained Si-on-insulator (SOI) and increased with increasing Ge concentration of the relaxed SiGe layer; i.e. the memory margin for the ε-Si SGOI capacitor-less memory cell (138.6 µA) at a 32 at% Ge concentration was 3.3 times higher than the SOI capacitor-less memory cell (43 µA). (paper)

A Review on Anodic Aluminum Oxide Methods for Fabrication of Nanostructures for Organic Solar Cells

DEFF Research Database (Denmark)

Goszczak, Arkadiusz Jaroslaw; Cielecki, Pawel Piotr

2018-01-01

Implementation of nanostructures into the organic solar cell (OSC) architecture has great influence on the device performance. Nanostructuring the active layer increases the interfacial area between donor and acceptor, which enhances the probability of exciton dissociation. Introduction of nanost......Implementation of nanostructures into the organic solar cell (OSC) architecture has great influence on the device performance. Nanostructuring the active layer increases the interfacial area between donor and acceptor, which enhances the probability of exciton dissociation. Introduction......, low fabrication cost and easy control over its nano-scale morphology, make AAO patterning methods an intriguing candidate for nanopatterning. Hence, in this work, we present a review on the fabrication techniques and on nanostructures from Anodic Aluminum Oxide (AAO) for OSC applications...

Ti–Al–O nanocrystal charge trapping memory cells fabricated by atomic layer deposition

International Nuclear Information System (INIS)

Cao, Zheng-Yi; Li, Ai-Dong; Li, Xin; Cao, Yan-Qiang; Wu, Di

2014-01-01

Charge trapping memory cells using Ti–Al–O (TAO) film as charge trapping layer and amorphous Al 2 O 3 as the tunneling and blocking layers were fabricated on Si substrates by atomic layer deposition method. As-deposited TAO films were annealed at 700 °C, 800 °C and 900 °C for 3 min in N 2 with a rapid thermal annealing process to form nanocrystals. High-resolution transmission electron microscopy and X-ray photoelectron spectroscopy were used to characterize the microstructure and band diagram of the heterostructures. The electrical characteristics and charge storage properties of the Al 2 O 3 /TAO/Al 2 O 3 /Si stack structures were also evaluated. Compared to 700 °C and 900 °C samples, the memory cells annealed at 800 °C exhibit better memory performance with larger memory window of 4.8 V at ± 6 V sweeping, higher program/erase speed and excellent endurance. - Highlights: • The charge trapping memory cells were fabricated by atomic layer deposition method. • The anneal temperature plays a key role in forming nanocrystals. • The memory cells annealed at 800 °C exhibit better memory performance. • The band alignment is beneficial to enhance the retention characteristics

CD4+ T cell count, HIV-1 viral loads and demographic variables of newly identified patients with HIV infection in Wuhan, China.

Science.gov (United States)

Liu, Man-Qing; Tang, Li; Kong, Wen-Hua; Zhu, Ze-Rong; Peng, Jin-Song; Wang, Xia; Yao, Zhong-Zhao; Schilling, Robert; Zhou, Wang

2013-10-01

In China, the rate of human immunodeficiency virus (HIV) testing is increasing among men who have sex with men. The purpose of the present study was to describe HIV-related biomarkers and selected demographic variables of persons with newly diagnosed HIV/AIDS, among men who have sex with men in particular, in Wuhan China. Demographic indicators, and CD4+ T cell counts and HIV-1 viral load were collected from individuals newly identified as HIV-1 antibody positive during 2011. Of 176 enrolled patients, 132 (75.0%) were men who have sex with men. This group was significantly younger and had higher CD4+ T cell counts than patients who were likely infected through heterosexual contact. Most men who have sex with men (56.6%) were discovered by initiative investigation. Among heterosexual patients CD4+ T cell counts and HIV-1 viral load were significantly correlated; among the group of men who have sex with men, no such association was found. Copyright © 2013 Wiley Periodicals, Inc.

Characterizing newly repopulated microglia in the adult mouse: impacts on animal behavior, cell morphology, and neuroinflammation.

Directory of Open Access Journals (Sweden)

Monica R P Elmore

Full Text Available Microglia are the primary immune cell in the brain and are postulated to play important roles outside of immunity. Administration of the dual colony-stimulating factor 1 receptor (CSF1R/c-Kit kinase inhibitor, PLX3397, to adult mice results in the elimination of ~99% of microglia, which remain eliminated for as long as treatment continues. Upon removal of the inhibitor, microglia rapidly repopulate the entire adult brain, stemming from a central nervous system (CNS resident progenitor cell. Using this method of microglial elimination and repopulation, the role of microglia in both healthy and diseased states can be explored. Here, we examine the responsiveness of newly repopulated microglia to an inflammatory stimulus, as well as determine the impact of these cells on behavior, cognition, and neuroinflammation. Two month-old wild-type mice were placed on either control or PLX3397 diet for 21 d to eliminate microglia. PLX3397 diet was then removed in a subset of animals to allow microglia to repopulate and behavioral testing conducted beginning at 14 d repopulation. Finally, inflammatory profiling of the microglia-repopulated brain in response to lipopolysaccharide (LPS; 0.25 mg/kg or phosphate buffered saline (PBS was determined 21 d after inhibitor removal using quantitative real time polymerase chain reaction (RT-PCR, as well as detailed analyses of microglial morphologies. We find mice with repopulated microglia to perform similarly to controls by measures of behavior, cognition, and motor function. Compared to control/resident microglia, repopulated microglia had larger cell bodies and less complex branching in their processes, which resolved over time after inhibitor removal. Inflammatory profiling revealed that the mRNA gene expression of repopulated microglia was similar to normal resident microglia and that these new cells appear functional and responsive to LPS. Overall, these data demonstrate that newly repopulated microglia function

Hydrodynamic lift for single cell manipulation in a femtosecond laser fabricated optofluidic chip

Directory of Open Access Journals (Sweden)

Bragheri Francesca

2017-08-01

Full Text Available Single cell sorting based either on fluorescence or on mechanical properties has been exploited in the last years in microfluidic devices. Hydrodynamic focusing allows increasing the efficiency of theses devices by improving the matching between the region of optical analysis and that of cell flow. Here we present a very simple solution fabricated by femtosecond laser micromachining that exploits flow laminarity in microfluidic channels to easily lift the sample flowing position to the channel portion illuminated by the optical waveguides used for single cell trapping and analysis.

Characterization of the nanosized porous structure of black Si solar cells fabricated via a screen printing process

Institute of Scientific and Technical Information of China (English)

Tang Yehua; Fei Jianming; Cao Hongbin; Zhou Chunlan; Wang Wenjing; Zhou Su; Zhao Yan; Zhao Lei; Li Hailing; Yan Baojun; Chen Jingwei

2012-01-01

A silicon (Si) surface with a nanosized porous structure was formed via simple wet chemical etching catalyzed by gold (Au) nanoparticles on p-type Cz-Si (100).The average reflectivity from 300 to 1200 nm was less than 1.5％.Black Si solar cells were then fabricated using a conventional production process.The results reflected the output characteristics of the cells fabricated using different etching depths and emitter dopant profiles.Heavier dopants and shallower etching depths should be adopted to optimize the black Si solar cell output characteristics.The efficiency at the optimized etching time and dopant profile was 12.17％.However,surface passivation and electrode contact due to the nanosized porous surface structure are still obstacles to obtaining high conversion efficiency for the black Si solar cells.

Fabrication and Characterization of Copper System Compound Semiconductor Solar Cells

Directory of Open Access Journals (Sweden)

Ryosuke Motoyoshi

2010-01-01

Full Text Available Copper system compound semiconductor solar cells were produced by a spin-coating method, and their cell performance and structures were investigated. Copper indium disulfide- (CIS- based solar cells with titanium dioxide (TiO2 were produced on F-doped SnO2 (FTO. A device based on an FTO/CIS/TiO2 structure provided better cell performance compared to that based on FTO/TiO2/CIS structure. Cupric oxide- (CuO- and cuprous oxide- (Cu2O- based solar cells with fullerene (C60 were also fabricated on FTO and indium tin oxide (ITO. The microstructure and cell performance of the CuO/C60 heterojunction and the Cu2O:C60 bulk heterojunction structure were investigated. The photovoltaic devices based on FTO/CuO/C60 and ITO/Cu2O:C60 structures provided short-circuit current density of 0.015 mAcm−2 and 0.11 mAcm−2, and open-circuit voltage of 0.045 V and 0.17 V under an Air Mass 1.5 illumination, respectively. The microstructures of the active layers were examined by X-ray diffraction and transmission electron microscopy.

Photoelectrode Fabrication of Dye-Sensitized Nanosolar Cells Using Multiple Spray Coating Technique

Directory of Open Access Journals (Sweden)

Chien-Chih Chen

2013-01-01

Full Text Available This paper presents a spray coating technique for fabricating nanoporous film of photoelectrode in dye-sensitized nanosolar cells (DSSCs. Spray coating can quickly fabricate nanoporous film of the photoelectrode with lower cost, which can further help the DSSCs to be commercialized in the future. This paper analyzed photoelectric conversion efficiency of the DSSCs using spray coated photoelectrode in comparison with the photoelectrode made with the doctor blade method. Spray coating can easily control transmittance of the photoelectrode through the multiple spray coating process. This work mainly used a dispersant with help of ultrasonic oscillation to prepare the required nano-TiO2 solution and then sprayed it on the ITO glasses. In this work, a motor-operated conveyor belt was built to transport the ITO glasses automatically for multiple spray coating and drying alternately. Experiments used transmittance of the photoelectrode as a fabrication parameter to analyze photoelectric conversion efficiency of the DSSCs. The influencing factors of the photoelectrode transmittance during fabrication are the spray flow rate, the spray distance, and the moving speed of the conveyor belt. The results show that DSSC with the photoelectrode transmittance of ca. 68.0 ± 1.5% and coated by the spray coating technique has the best photoelectric conversion efficiency in this work.

Triple-junction thin-film silicon solar cell fabricated on periodically textured substrate with a stabilized efficiency of 13.6%

Science.gov (United States)

Sai, Hitoshi; Matsui, Takuya; Koida, Takashi; Matsubara, Koji; Kondo, Michio; Sugiyama, Shuichiro; Katayama, Hirotaka; Takeuchi, Yoshiaki; Yoshida, Isao

2015-05-01

We report a high-efficiency triple-junction thin-film silicon solar cell fabricated with the so-called substrate configuration. It was verified whether the design criteria for developing single-junction microcrystalline silicon (μc-Si:H) solar cells are applicable to multijunction solar cells. Furthermore, a notably high short-circuit current density of 32.9 mA/cm2 was achieved in a single-junction μc-Si:H cell fabricated on a periodically textured substrate with a high-mobility front transparent contacting layer. These technologies were also combined into a-Si:H/μc-Si:H/μc-Si:H triple-junction cells, and a world record stabilized efficiency of 13.6% was achieved.

Development, Characterization and Cell Cultural Response of 3D Biocompatible Micro-Patterned Poly-ε-Caprolactone Scaffolds Designed and Fabricated Integrating Lithography and Micromolding Fabrication Techniques

KAUST Repository

Limongi, Tania; Miele, Ermanno; Shalabaeva, Victoria; Rocca, Rosanna La; Schipani, Rossana; Malara, Natalia; Angelis, Francesco de; Giugni, Andrea; Di Fabrizio, Enzo M.

2014-01-01

Scaffold design and fabrication are very important subjects for biomaterial, tissue engineering and regenerative medicine research playing a unique role in tissue regeneration and repair. Among synthetic biomaterials Poly-ε- Caprolactone (PCL) is very attractive bioresorbable polyester due to its high permeability, biodegradability and capacity to be blended with other biopolymers. Thanks to its ability to naturally degrade in tissues, PCL has a great potential as a new material for implantable biomedical micro devices. This work focuses on the establishment of a micro fabrication process, by integrating lithography and micromolding fabrication techniques, for the realization of 3D microstructure PCL devices. Scaffold surface exhibits a combination in the patterned length scale; cylindrical pillars of 10 μm height and 10 μm diameter are arranged in a hexagonal lattice with periodicity of 30 μm and their sidewalls are nano-sculptured, with a regular pattern of grooves leading to a spatial modulation in the z direction. In order to demonstrate that these biocompatible pillared PCL substrates are suitable for a proper cell growth, NIH/3T3 mouse embryonic fibroblasts were seeded on them and cells key adhesion parameters were evaluated. Scanning Electron Microscopy and immunofluorescence analysis were carried out to check cell survival, proliferation and adhesion; cells growing on the PCL substrates appeared healthy and formed a well-developed network in close contact with the micro and nano features of the pillared surface. Those 3D scaffolds could be a promising solution for a wide range of applications within tissue engineering and regenerative medicine applications.

Development, Characterization and Cell Cultural Response of 3D Biocompatible Micro-Patterned Poly-ε-Caprolactone Scaffolds Designed and Fabricated Integrating Lithography and Micromolding Fabrication Techniques

KAUST Repository

Limongi, Tania

2014-12-12

Scaffold design and fabrication are very important subjects for biomaterial, tissue engineering and regenerative medicine research playing a unique role in tissue regeneration and repair. Among synthetic biomaterials Poly-ε- Caprolactone (PCL) is very attractive bioresorbable polyester due to its high permeability, biodegradability and capacity to be blended with other biopolymers. Thanks to its ability to naturally degrade in tissues, PCL has a great potential as a new material for implantable biomedical micro devices. This work focuses on the establishment of a micro fabrication process, by integrating lithography and micromolding fabrication techniques, for the realization of 3D microstructure PCL devices. Scaffold surface exhibits a combination in the patterned length scale; cylindrical pillars of 10 μm height and 10 μm diameter are arranged in a hexagonal lattice with periodicity of 30 μm and their sidewalls are nano-sculptured, with a regular pattern of grooves leading to a spatial modulation in the z direction. In order to demonstrate that these biocompatible pillared PCL substrates are suitable for a proper cell growth, NIH/3T3 mouse embryonic fibroblasts were seeded on them and cells key adhesion parameters were evaluated. Scanning Electron Microscopy and immunofluorescence analysis were carried out to check cell survival, proliferation and adhesion; cells growing on the PCL substrates appeared healthy and formed a well-developed network in close contact with the micro and nano features of the pillared surface. Those 3D scaffolds could be a promising solution for a wide range of applications within tissue engineering and regenerative medicine applications.

Combination therapy with carfilzomib, lenalidomide and dexamethasone (KRd) results in an unprecedented purity of the stem cell graft in newly diagnosed patients with myeloma.

Science.gov (United States)

Tageja, Nishant; Korde, Neha; Kazandjian, Dickran; Panch, Sandhya; Manasanch, Elisabet; Bhutani, Manisha; Kwok, Mary; Mailankody, Sham; Yuan, Constance; Stetler-Stevenson, Maryalice; Leitman, Susan F; Sportes, Claude; Landgren, Ola

2018-05-04

Still, many physicians give 4 cycles of combination therapy to multiple myeloma patients prior to collection of stem cells for autologous bone marrow transplant. This tradition originates from older doxorubicin-containing regiments which limited the number of cycles due to cumulative cardiotoxicity. Using older regiments, most patients had residual myeloma cells in their autologous stem-cell grafts during collection. Emerging data show that newly diagnosed multiple myeloma patients treated with modern carfilzomib/lenalidomide/dexamethasone (KRd) therapy, on average, take 6 cycles until reaching minimal residual disease (MRD) negativity. We assessed newly diagnosed patients treated with KRd focusing MRD status both in the individual patient's bone marrow, and the corresponding autologous hematopoietic progenitor cell grafts during collection. Per protocol, stem-cell collection was allowed after 4 to 8 cycles of KRd. We found similar stem-cell yield independent of the number of cycles of KRd. At stem-cell collection, 11/30 patients (36.6%) were MRD negative in their bone marrow; all 11 patients had MRD negative hematopoietic progenitor cell grafts. Furthermore, 18/19 patients who were MRD positive in their bone marrows also had MRD negative hematopoietic progenitor cell grafts. These observations support 6 cycles of KRd as an efficacious and safe induction strategy prior to stem-cell collection.

Method to fabricate high performance tubular solid oxide fuel cells

Science.gov (United States)

Chen, Fanglin; Yang, Chenghao; Jin, Chao

2013-06-18

In accordance with the present disclosure, a method for fabricating a solid oxide fuel cell is described. The method includes forming an asymmetric porous ceramic tube by using a phase inversion process. The method further includes forming an asymmetric porous ceramic layer on a surface of the asymmetric porous ceramic tube by using a phase inversion process. The tube is co-sintered to form a structure having a first porous layer, a second porous layer, and a dense layer positioned therebetween.

Fabrication of Graphene Oxide Dispersed DLC/PDMS Substrates and Human Mesenchymal Stem Cell Culture(Researches)

OpenAIRE

伴, 雅人; Masahito, Ban

2016-01-01

Graphene Oxide (GO) dispersed DLC (diamond-like carbon) thin film deposited PDMS substrates were fabricated with plasma treatments and dip coating methods. It was found from cell culture tests using the substrates as scaffolds human mesenchymal stem cells (hMSCs) indicated larger F-actin areas compared with the substrates without GO and/or DLC.

Flexible dye-sensitized solar cell fabricated on plastic substrate by laser-detachment and press method

International Nuclear Information System (INIS)

Kim, Choonghoe; Kim, Seongsu; Lee, Myeongkyu

2013-01-01

This report shows that flexible dye-sensitized solar cell can be fabricated by a laser-detachment and press method where the TiO 2 electrode typically sintered on glass source substrate is detached by a laser pulse and then is firmly adhered to the conductive plastic substrate by applying a high pressure. The cells fabricated by this process exhibited 36–43% smaller photocurrent and efficiency than the conventional glass cells with directly coated TiO 2 electrodes. It was attributed to the lowered dye coverage and electron diffusion length, both of which originate from the press-induced reduction of TiO 2 porosity. A maximum efficiency of 5.68% was obtained for the plastic cell. Bending of the electrode led to 20% loss of the current density and efficiency. However, no further performance degradation was observed even when the bending cycle was increased to 100, 300, and 500 times. This indicates that the bending-induced degradation of TiO 2 electrode on the plastic substrate takes place at the first bending.

Fabrication and photovoltaic properties of ZnO nanorods/perovskite solar cells

Energy Technology Data Exchange (ETDEWEB)

Shirahata, Yasuhiro; Tanaike, Kohei; Akiyama, Tsuyoshi; Fujimoto, Kazuya; Suzuki, Atsushi; Balachandran, Jeyadevan; Oku, Takeo, E-mail: oku@mat.usp.ac.jp [Department of Materials Science, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga 522-8533 (Japan)

2016-02-01

ZnO nanorods/perovskite solar cells with different lengths of ZnO nanorods were fabricated. The ZnO nanorods were prepared by chemical bath deposition and directly confirmed to be hexagon-shaped nanorods. The lengths of the ZnO nanorads were controlled by deposition condition of ZnO seed layer. Photovoltaic properties of the ZnO nanorods/CH{sub 3}NH{sub 3}PbI{sub 3} solar cells were investigated by measuring current density-voltage characteristics and incident photon to current conversion efficiency. The highest conversion efficiency was obtained in ZnO nanorods/CH{sub 3}NH{sub 3}PbI{sub 3} with the longest ZnO nanorods.

Bismuth-catalyzed and doped silicon nanowires for one-pump-down fabrication of radial junction solar cells.

Science.gov (United States)

Yu, Linwei; Fortuna, Franck; O'Donnell, Benedict; Jeon, Taewoo; Foldyna, Martin; Picardi, Gennaro; Roca i Cabarrocas, Pere

2012-08-08

Silicon nanowires (SiNWs) are becoming a popular choice to develop a new generation of radial junction solar cells. We here explore a bismuth- (Bi-) catalyzed growth and doping of SiNWs, via vapor-liquid-solid (VLS) mode, to fabricate amorphous Si radial n-i-p junction solar cells in a one-pump-down and low-temperature process in a single chamber plasma deposition system. We provide the first evidence that catalyst doping in the SiNW cores, caused by incorporating Bi catalyst atoms as n-type dopant, can be utilized to fabricate radial junction solar cells, with a record open circuit voltage of V(oc) = 0.76 V and an enhanced light trapping effect that boosts the short circuit current to J(sc) = 11.23 mA/cm(2). More importantly, this bi-catalyzed SiNW growth and doping strategy exempts the use of extremely toxic phosphine gas, leading to significant procedure simplification and cost reduction for building radial junction thin film solar cells.

Fabrication of mesoporous polymer monolith: a template-free approach.

Science.gov (United States)

Okada, Keisuke; Nandi, Mahasweta; Maruyama, Jun; Oka, Tatsuya; Tsujimoto, Takashi; Kondoh, Katsuyoshi; Uyama, Hiroshi

2011-07-14

Mesoporous polyacrylonitrile (PAN) monolith has been fabricated by a template-free approach using the unique affinity of PAN towards a water/dimethyl sulfoxide (DMSO) mixture. A newly developed Thermally Induced Phase Separation Technique (TIPS) has been used to obtain the polymer monoliths and their microstructures have been controlled by optimizing the concentration and cooling temperature.

Ultrafast Flame Annealing of TiO2 Paste for Fabricating Dye-Sensitized and Perovskite Solar Cells with Enhanced Efficiency.

Science.gov (United States)

Kim, Jung Kyu; Chai, Sung Uk; Cho, Yoonjun; Cai, Lili; Kim, Sung June; Park, Sangwook; Park, Jong Hyeok; Zheng, Xiaolin

2017-11-01

Mesoporous TiO 2 nanoparticle (NP) films are broadly used as electrodes in photoelectrochemical cells, dye-sensitized solar cells (DSSCs), and perovskite solar cells (PSCs). State-of-the-art mesoporous TiO 2 NP films for these solar cells are fabricated by annealing TiO 2 paste-coated fluorine-doped tin oxide glass in a box furnace at 500 °C for ≈30 min. Here, the use of a nontraditional reactor, i.e., flame, is reported for the high throughput and ultrafast annealing of TiO 2 paste (≈1 min). This flame-annealing method, compared to conventional furnace annealing, exhibits three distinct benefits. First, flame removes polymeric binders in the initial TiO 2 paste more completely because of its high temperature (≈1000 °C). Second, flame induces strong interconnections between TiO 2 nanoparticles without affecting the underlying transparent conducting oxide substrate. Third, the flame-induced carbothermic reduction on the TiO 2 surface facilitates charge injection from the dye/perovskite to TiO 2 . Consequently, when the flame-annealed mesoporous TiO 2 film is used to fabricate DSSCs and PSCs, both exhibit enhanced charge transport and higher power conversion efficiencies than those fabricated using furnace-annealed TiO 2 films. Finally, when the ultrafast flame-annealing method is combined with a fast dye-coating method to fabricate DSSC devices, its total fabrication time is reduced from over 3 h to ≈10 min. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Changes in immunological status among newly-diagnosed HIV-infected in Denmark 1995-2005

DEFF Research Database (Denmark)

Hoegh, S.; Lohse, N.; Hansen, A.B.

2008-01-01

INTRODUCTION: The incidence of new HIV diagnoses in Denmark has remained stable since 1991, but it has increased among the subgroup of homosexual men in recent years. This may reflect an actual increase in newly infected, e.g. as a result of increased risk behaviour, or it may reflect increased HIV....... MATERIALS AND METHODS: Observational study based on the Danish HIV Cohort Study, which includes all adults seen at Danish HIV clinics since 1995. RESULTS: From 2000 to 2004 the number of newly-infected homosexual men increased (from 69 to 123), particularly in persons under 30 years (from 5 to 42......). The median CD4 cell count at the time of diagnosis increased in this group (median 19.1 cells/microL per year [95% CI: 3.7-11.3]), while it remained stable among heterosexually infected. The number of newly-diagnosed homosexually infected under 30 years with a CD4 cell count over 400 cells/microL increased...

Prognostic Significance of Blood Transfusion in Newly Diagnosed Multiple Myeloma Patients without Autologous Hematopoietic Stem Cell Transplantation

Science.gov (United States)

Fan, Liping; Fu, Danhui; Zhang, Jinping; Wang, Qingqing; Ye, Yamei; Xie, Qianling

2017-01-01

The aim of this study was to evaluate whether blood transfusions affect overall survival (OS) and progression-free survival (PFS) in newly diagnosed multiple myeloma (MM) patients without hematopoietic stem cell transplantation. A total of 181 patients were enrolled and divided into two groups: 68 patients in the transfused group and 113 patients in the nontransfused group. Statistical analyses showed that there were significant differences in ECOG scoring, Ig isotype, platelet (Plt) counts, hemoglobin (Hb) level, serum creatinine (Scr) level, and β2-microglobulin (β2-MG) level between the two groups. Univariate analyses showed that higher International Staging System staging, Plt counts blood transfusion was associated with PFS but not OS in MM patients. Multivariate analyses showed that blood transfusion was not an independent factor for PFS in MM patients. Our preliminary results suggested that newly diagnosed MM patients may benefit from a liberal blood transfusion strategy, since blood transfusion is not an independent impact factor for survival. PMID:28567420

Wet-process Fabrication of Low-cost All-solid Wire-shaped Solar Cells on Manganese-plated Electrodes

International Nuclear Information System (INIS)

Fan, Xing; Zhang, Xiaoying; Zhang, Nannan; Cheng, Li; Du, Jun; Tao, Changyuan

2015-01-01

Highlights: • All-solid wire-shaped flexible solar cells are firstly assembled on low-cost Mn-plated fibers. • Energy efficiency improved by >27% after coating a layer of Mn on various substrates. • The cell is fabricated via wet process under low temperature and mild pH conditions. • Stable flexible solar cells are realized on lightweight and low-cost polymer fiber. - Abstract: All-solid wire-shaped flexible solar cells are assembled for the first time on low-cost Mn-plated wires through wet-process fabrication under low temperature and mild pH conditions. With a price cheap as the steel, metal Mn can be easily plated on almost any substrates, and evidently promote the photovoltaic efficiency of wire-shaped solar cells on various traditional metal wire substrates, such as Fe and Ti, by 27% and 65%, respectively. Flexible solar cell with much lower cost and weight is assembled on Mn-plated polymer substrate, and is still capable of giving better performance than that on Fe or Ti substrate. Both its mechanical and chemical stability are good for future weaving applications. Owing to the wire-type structure, such low-cost metals as Mn, which are traditionally regarded as unsuitable for solar cells, may provide new opportunities for highly efficient solar cells

Fabrication of PbS quantum dots and their applications in solar cells based on ZnO nanorod arrays

Science.gov (United States)

Kumar, Dinesh; Chaudhary, Sujeet; Pandya, Dinesh K.

2018-05-01

An efficient, inexpensive and large area scalable approach based on sol-gel technique is presented to fabricate quantum dots (QDs) of PbS. Size of the QDs is tuned by the varying the bath concentrations in the range of 50-200 mM. Transmission electron microscopy (TEM) studies confirm the growth of spherically shaped ˜5.6 nm QDs at 50 mM bath concentration. The optical bandgap of the QDs is found to be ˜0.9 eV and corresponds to the size obtained from TEM studies. ZnO/PbS solar cells are fabricated by sensitizing the ZnO nanorods with PbS QDs. The fabricated solar cells demonstrate the highest open circuit voltage ˜200 mV and short circuit current density ˜0.81 µA/cm2.

CHOEP-21 chemotherapy for newly diagnosed nodal peripheral T-cell lymphomas (PTCLs) in Maharaj Nakorn Chiang Mai Hospital.

Science.gov (United States)

Rattarittamrong, Ekarat; Norasetthada, Lalita; Tantiworawit, Adisak; Chai-Adisaksopha, Chatree; Nawarawong, Weerasak

2013-11-01

To determine the effectiveness and tolerability of the combination of chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) with the addition of etoposide (CHOEP-21) for newly diagnosed nodal peripheral T-cell lymphomas (PTCLs). Between January 2009 and October 2011, patients aged 18 to 60 years with newly diagnosed nodal PTCLs at the Maharaj Nakorn Chiang Mai Hospital were enrolled to receive CHOEP-21 every three weeks for eight cycles. G-CSF prophylaxis was given to all patients. Twenty-four patients were enrolled. Twenty of them were male with a median age of 49 years. The majority of patients (66.7%) had PTCL, not otherwise specified (PTCL, NOS), and 95.8% of the patients were in stage III or IV. The overall response rate was 58% with 42% having complete response. The response rates were better among patients with ALK-negative anaplastic large cell lymphoma (ALCL; 100%) and angioimmunoblastic T-cell lymphoma (AITL; 85%) than those with PTCL, NOS (44%). With a median follow-up of 21 months, the patients had an estimated 2-year event-free survival, and an overall survival rate of 37.6% and 54.4%, respectively. The most common adverse effects were infection and hematologic toxicities that was manageable. Although CHOEP-21 induced favorable responses in patients with ALK-negative ALCL and AITL, the responses were not durable and further therapy is mandated in management of patients with nodal PTCL.

Silicon Web Process Development. [for solar cell fabrication

Science.gov (United States)

Duncan, C. S.; Seidensticker, R. G.; Hopkins, R. H.; Mchugh, J. P.; Hill, F. E.; Heimlich, M. E.; Driggers, J. M.

1979-01-01

Silicon dendritic web, ribbon form of silicon and capable of fabrication into solar cells with greater than 15% AMl conversion efficiency, was produced from the melt without die shaping. Improvements were made both in the width of the web ribbons grown and in the techniques to replenish the liquid silicon as it is transformed to web. Through means of improved thermal shielding stress was reduced sufficiently so that web crystals nearly 4.5 cm wide were grown. The development of two subsystems, a silicon feeder and a melt level sensor, necessary to achieve an operational melt replenishment system, is described. A gas flow management technique is discussed and a laser reflection method to sense and control the melt level as silicon is replenished is examined.

The thermomechanical stability of micro-solid oxide fuel cells fabricated on anodized aluminum oxide membranes

Science.gov (United States)

Kwon, Chang-Woo; Lee, Jae-Il; Kim, Ki-Bum; Lee, Hae-Weon; Lee, Jong-Ho; Son, Ji-Won

2012-07-01

The thermomechanical stability of micro-solid oxide fuel cells (micro-SOFCs) fabricated on an anodized aluminum oxide (AAO) membrane template is investigated. The full structure consists of the following layers: AAO membrane (600 nm)/Pt anode/YSZ electrolyte (900 nm)/porous Pt cathode. The utilization of a 600-nm-thick AAO membrane significantly improves the thermomechanical stability due to its well-known honeycomb-shaped nanopore structure. Moreover, the Pt anode layer deposited in between the AAO membrane and the YSZ electrolyte preserves its integrity in terms of maintaining the triple-phase boundary (TPB) and electrical conductivity during high-temperature operation. Both of these results guarantee thermomechanical stability of the micro-SOFC and extend the cell lifetime, which is one of the most critical issues in the fabrication of freestanding membrane-type micro-SOFCs.

Poly(L-lactic acid) and polyurethane nanofibers fabricated by solution blow spinning as potential substrates for cardiac cell culture

Energy Technology Data Exchange (ETDEWEB)

Tomecka, Ewelina, E-mail: etomecka@ch.pw.edu.pl [Department of Microbioanalytics, Institute of Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Wojasinski, Michal [Department of Biotechnology and Bioprocess Engineering, Faculty of Chemical and Process Engineering, Warsaw University of Technology, Waryńskiego 1, 00-645 Warsaw (Poland); Jastrzebska, Elzbieta; Chudy, Michal [Department of Microbioanalytics, Institute of Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Ciach, Tomasz [Department of Biotechnology and Bioprocess Engineering, Faculty of Chemical and Process Engineering, Warsaw University of Technology, Waryńskiego 1, 00-645 Warsaw (Poland); Brzozka, Zbigniew [Department of Microbioanalytics, Institute of Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)

2017-06-01

This paper presents a comparison and evaluation of cardiac cell proliferation on poly(L-lactic acid) (PLLA) and polyurethane (PU) nanofibrous mats fabricated by solution blow spinning (SBS). Three different cardiac cell lines: rat cardiomyoblasts (H9C2 line), human (HCM) and rat cardiomyocytes (RCM) were used for experiments. Cell morphology, orientation and proliferation were investigated on non-modified and protein-modified (fibronectin, collagen, gelatin, laminin, poly-L-lysine) surfaces of both types of nanofibers. Obtained results of cell culture on nanofibers surfaces were compared to the results of cell culture on polystyrene (PS) surfaces modified in the same way. The results indicated that in most cases polymeric nanofibers (PLLA and PU) are better substrates for cardiac cell culture than PS surfaces. All types of investigated cells, cultured on nanofibers (PLLA and PU), had more elongated shape than cells cultured on PS surfaces. Moreover, cells were arranged in parallel to each other, according to fibers orientation. Additionally, it was shown that the protein modifications of investigated surfaces influenced on cell proliferation. Therefore, we suggest that the cardiac cell culture on nanofibrous mats fabricated by SBS could be more advanced experimental in vitro model for studies on the effect of various cardiac drugs than traditional culture on PS surface. - Highlights: • Solution blow spinning was used for PLLA and PU nanofibers fabrication. • Three cardiac cell lines differing in age and origin were used for experiments. • The protein modifications of investigated surfaces influenced on cell proliferation. • Nanofibers are better substrates for cardiac cell culture than PS surface. • Nanofibers enable cultivating cardiac cells under conditions similar to in vivo.

Poly(L-lactic acid) and polyurethane nanofibers fabricated by solution blow spinning as potential substrates for cardiac cell culture

International Nuclear Information System (INIS)

Tomecka, Ewelina; Wojasinski, Michal; Jastrzebska, Elzbieta; Chudy, Michal; Ciach, Tomasz; Brzozka, Zbigniew

2017-01-01

This paper presents a comparison and evaluation of cardiac cell proliferation on poly(L-lactic acid) (PLLA) and polyurethane (PU) nanofibrous mats fabricated by solution blow spinning (SBS). Three different cardiac cell lines: rat cardiomyoblasts (H9C2 line), human (HCM) and rat cardiomyocytes (RCM) were used for experiments. Cell morphology, orientation and proliferation were investigated on non-modified and protein-modified (fibronectin, collagen, gelatin, laminin, poly-L-lysine) surfaces of both types of nanofibers. Obtained results of cell culture on nanofibers surfaces were compared to the results of cell culture on polystyrene (PS) surfaces modified in the same way. The results indicated that in most cases polymeric nanofibers (PLLA and PU) are better substrates for cardiac cell culture than PS surfaces. All types of investigated cells, cultured on nanofibers (PLLA and PU), had more elongated shape than cells cultured on PS surfaces. Moreover, cells were arranged in parallel to each other, according to fibers orientation. Additionally, it was shown that the protein modifications of investigated surfaces influenced on cell proliferation. Therefore, we suggest that the cardiac cell culture on nanofibrous mats fabricated by SBS could be more advanced experimental in vitro model for studies on the effect of various cardiac drugs than traditional culture on PS surface. - Highlights: • Solution blow spinning was used for PLLA and PU nanofibers fabrication. • Three cardiac cell lines differing in age and origin were used for experiments. • The protein modifications of investigated surfaces influenced on cell proliferation. • Nanofibers are better substrates for cardiac cell culture than PS surface. • Nanofibers enable cultivating cardiac cells under conditions similar to in vivo.

Simple fabrication of back contact heterojunction solar cells by plasma ion implantation

Science.gov (United States)

Koyama, Koichi; Yamaguchi, Noboru; Hironiwa, Daisuke; Suzuki, Hideo; Ohdaira, Keisuke; Matsumura, Hideki

2017-08-01

A back-contact amorphous-silicon (a-Si)/crystalline silicon (c-Si) heterojunction is one of the most promising structures for high-efficiency solar cells. However, the patterning of back-contact electrodes causes the increase in fabrication cost. Thus, to simplify the fabrication of back-contact cells, we attempted to form p-a-Si/i-a-Si/c-Si and n-a-Si/i-a-Si/c-Si regions by the conversion of a patterned area of p-a-Si/i-a-Si/c-Si to n-a-Si/i-a-Si/c-Si by plasma ion implantation. It is revealed that the conversion of the conduction type can be realized by the plasma ion implantation of phosphorus (P) atoms into p-a-Si/i-a-Si/c-Si regions, and also that the quality of passivation can be kept sufficiently high, the same as that before ion implantation, when the samples are annealed at around 250 °C and also when the energy and dose of ion implantation are appropriately chosen for fitting to a-Si layer thickness and bulk c-Si carrier density.

An improved out-cell to in-cell rapid transfer system at the HFEF/South

International Nuclear Information System (INIS)

Bacca, J.P.; Sherman, E.K.

1991-01-01

This paper reports on Argonne National Laboratory's Fuel Cycle Facility (FCF) (formerly named Hot Fuel Examination Facility-South) (HFEF/South) which is currently being refurbished and upgraded in preparation for demonstrating remote, fast reactor metal-fuel reprocessing and refabrication, as part of the Integral Fast Reactor (IFR) Program. Among the FCF hot-cell system upgrades being provided is a newly fabricated, direct, out-of-cell to in-cell, small-item transfer system for the FCF argon cell. This system will enable the rapid transfer of selected small items from the hot cell exterior into the argon cell (argon-gas atmosphere) of the facility, without necessitating the use of formerly employed, very time-consuming, and quite laborious procedures. The new system will be especially valuable for the rapid insertion of IFR fuel processing makeup materials and small tools into the argon cell, and for use in argon cell and overall FCF radioactive contamination-control activities

ZnO nanorods/AZO photoanode for perovskite solar cells fabricated in ambient air

Science.gov (United States)

La Ferrara, Vera; De Maria, Antonella; Rametta, Gabriella; Della Noce, Marco; Vittoria Mercaldo, Lucia; Borriello, Carmela; Bruno, Annalisa; Delli Veneri, Paola

2017-08-01

ZnO nanorods are a good candidate for replacing standard photoanodes, such as TiO2, in perovskite solar cells and in principle superseding the high performances already obtained. This is possible because ZnO nanorods have a fast electron transport rate due to their large surface area. An array of ZnO nanorods is grown by chemical bath deposition starting from Al-doped ZnO (AZO) used both as a seed layer and as an efficient transparent anode in the visible spectral range. In particular, in this work we fabricate methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells using glass/AZO/ZnO nanorods/perovskite/Spiro-OMeTAD/Au as the architecture. The growth of ZnO nanorods has been optimized by varying the precursor concentrations, growth time and solution temperature. All the fabrication process and photovoltaic characterizations have been carried out in ambient air and the devices have not been encapsulated. Power conversion efficiency as high as 7.0% has been obtained with a good stability over 20 d. This is the highest reported value to the best of our knowledge and it is a promising result for the development of perovskite solar cells based on ZnO nanorods and AZO.

Fabrication of Organic Bulk Heterojunction Solar Cells on Flexible Substrates

Science.gov (United States)

Calderon, Gabriel; Merced-Sanabria, Milzaida; Carradero-Santiago, Carolyn; Vedrine-Pauléus, Josee

2015-03-01

The active layer for the organic solar cells fabricated is composed of P3HT:PCBM, poly(3-hexylthiophene) (P3HT) as electron donor and phenyl-C61-butyric acid methyl ester(PCBM) as electron acceptor. These polymers were used due to their promising characteristics for devices such as bulk heterojunction solar devices. We used polyethylene terephthalate (PET) substrates, a highly flexible plastic, with indium tin oxide (ITO) as the transparent conducting anode for the device, and UV lithography technique to pattern the ITO; this is to facilitate multiple devices on a single substrate. The fabrication process for pattern transfer incorporates developing and etching processes. We diluted the HCl and DI water to etch out the ITO. PEDOT:PSS and active layer of P3HT:PCBM were deposited on (3.0 sq-cm) patterned of ITO/PET by spin coating method. The cathode was thermally evaporated with Al. We characterized the device using a sourcemeter. We also simulated portions of the device using PET on graphene as the substrate.

Hydrogenated amorphous silicon solar cells fabricated at low substrate temperature 110°C on flexible PET substrate

Science.gov (United States)

Ramakrishna, M.; Kumari, Juhi; Venkanna, K.; Agarwal, Pratima

2018-05-01

In this paper, we report a-Si:H solar cells fabricated on flexible Polyethylene terephthalate (PET) and corning glass. The a-Si:H thin films were prepared at low substrate temperature (110oC) on corning 1737 glass with different rf powers. The influence of rf power on structural and optoelectronic properties of i-a-Si:H were studied. The films deposited at rf power 50W show less broadening of peak. This indicates these films are more ordered. With this optimized parameter for i-layer, solar cells fabricated on flexible PET substrate show best efficiency of 3.3% whereas on corning glass 3.82%.

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization.

Science.gov (United States)

Liu, Feng; Ferdous, Sunzida; Wan, Xianjian; Zhu, Chenhui; Schaible, Eric; Hexemer, Alexander; Wang, Cheng; Russell, Thomas P

2017-01-29

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices have used devices prepared by spin coating, a process that is not amenable to large-scale fabrication. This mismatch in device fabrication makes it difficult to translate quantitative results obtained in the laboratory to the commercial level, making optimization difficult. Using a mini-slot die coater, this mismatch can be resolved by translating the commercial process to the laboratory and characterizing the structure formation in the active layer of the device in real time and in situ as films are coated onto a substrate. The evolution of the morphology was characterized under different conditions, allowing us to propose a mechanism by which the structures form and grow. This mini-slot die coater offers a simple, convenient, material efficient route by which the morphology in the active layer can be optimized under industrially relevant conditions. The goal of this protocol is to show experimental details of how a solar cell device is fabricated using a mini-slot die coater and technical details of running in situ structure characterization using the mini-slot die coater.

Fabrication of ultrahigh density metal-cell-metal crossbar memory devices with only two cycles of lithography and dry-etch procedures

KAUST Repository

Zong, Baoyu; Goh, J. Y.; Guo, Zaibing; Luo, Ping; Wang, Chenchen; Qiu, Jinjun; Ho, Pin; Chen, Yunjie; Zhang, Mingsheng; Han, Guchang

2013-01-01

A novel approach to the fabrication of metal-cell-metal trilayer memory devices was demonstrated by using only two cycles of lithography and dry-etch procedures. The fabricated ultrahigh density crossbar devices can be scaled down to ≤70 nm in half

Concise Review: Fabrication, Customization, and Application of Cell Mimicking Microparticles in Stem Cell Science.

Science.gov (United States)

Labriola, Nicholas R; Azagury, Aharon; Gutierrez, Robert; Mathiowitz, Edith; Darling, Eric M

2018-02-01

Stem and non-stem cell behavior is heavily influenced by the surrounding microenvironment, which includes other cells, matrix, and potentially biomaterials. Researchers have been successful in developing scaffolds and encapsulation techniques to provide stem cells with mechanical, topographical, and chemical cues to selectively direct them toward a desired differentiation pathway. However, most of these systems fail to present truly physiological replications of the in vivo microenvironments that stem cells are typically exposed to in tissues. Thus, cell mimicking microparticles (CMMPs) have been developed to more accurately recapitulate the properties of surrounding cells while still offering ways to tailor what stimuli are presented. This nascent field holds the promise of reducing, or even eliminating, the need for live cells in select, regenerative medicine therapies, and diagnostic applications. Recent, CMMP-based studies show great promise for the technology, yet only reproduce a small subset of cellular characteristics from among those possible: size, morphology, topography, mechanical properties, surface molecules, and tailored chemical release to name the most prominent. This Review summarizes the strengths, weaknesses, and ideal applications of micro/nanoparticle fabrication and customization methods relevant to cell mimicking and provides an outlook on the future of this technology. Moving forward, researchers should seek to combine multiple techniques to yield CMMPs that replicate as many cellular characteristics as possible, with an emphasis on those that most strongly influence the desired therapeutic effects. The level of flexibility in customizing CMMP properties allows them to substitute for cells in a variety of regenerative medicine, drug delivery, and diagnostic systems. Stem Cells Translational Medicine 2018;7:232-240. © 2018 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Perovskite solar cells for roll-to-roll fabrication

Directory of Open Access Journals (Sweden)

Uddin Ashraf

2017-01-01

Full Text Available Perovskite solar cell (PSCs is considered as the game changer in emerging photovoltaics technology. The highest certified efficiency is 22% with high temperature processed (∼500 °C TiO2 based electron transport layer (ETL. High temperature process is a rudimentary hindrance towards roll-to-roll processing of PSCs on flexible substrates. Low temperature solution process (<150 °C ZnO based ETL is one of the most promising candidate for large scale roll-to-roll fabrication of cells as it has nearly identical electron affinity (4.2 eV of TiO2. The mixed organic perovskite (MA0.6FA0.4PbI3 devices with Al doped ZnO (AZO ETL demonstrate average cell efficiency over 16%, which is the highest ever reported efficiency for this device configuration. The energy level alignment and related interfacial charge transport dynamics at the interface of ZnO and perovskite films and the adjacent charge transport layers are investigated. Significantly improved device stability, hysteresis free device photocurrent have been observed in MA0.6FA0.4PbI3 cells. A systematic electrochemical impedance spectroscopy, frequency dependent capacitance spectra, surface morphology and topography characterization have been conducted to understand the role of interfacial electronic properties between perovskite and neighbouring layers in perovskite device. A standardized degradation study, interfacial electronic property and capacitive spectra analysis of aged device, have been measured to understand the enhanced device stability in mixed MA0.6FA0.4PbI3 cells. Slow perovskite material decomposition rate and augmented device lifetime with AZO based devices have been found to be correlated with the more hydrophobic and acidic nature of AZO surface compared to pristine ZnO film.

Using injection molding and reversible bonding for easy fabrication of magnetic cell trapping and sorting devices

Science.gov (United States)

Royet, David; Hériveaux, Yoann; Marchalot, Julien; Scorretti, Riccardo; Dias, André; Dempsey, Nora M.; Bonfim, Marlio; Simonet, Pascal; Frénéa-Robin, Marie

2017-04-01

Magnetism and microfluidics are two key elements for the development of inexpensive and reliable tools dedicated to high-throughput biological analysis and providing a large panel of applications in domains ranging from fundamental biology to medical diagnostics. In this work, we introduce a simple protocol, relying on injection molding and reversible bonding for fabrication of magnetic cell trapping and sorting devices using only standard soft-lithography equipment. Magnetic strips or grids made of Polydimethylsiloxane (PDMS) doped with hard (NdFeB) or soft (carbonyl iron) magnetic powders were integrated at the bottom of whole PDMS chips. Preliminary results show the effective deviation/trapping of magnetic beads or magnetically-labeled bacteria as the sample flows through the microchannel, proving the potential of this rapid prototyping approach for easy fabrication of magnetic cell sorters.

Fabrication and characterization of artificial hair cell sensor based on MWCNT-PDMS composite

Science.gov (United States)

Kim, Chi Yeon; Lee, Hyun Sup; Cho, Yo Han; Joh, Cheeyoung; Choi, Pyung; Park, Seong Jin

2011-06-01

The aim of this work is to design and fabricate a flow sensor using an artificial hair cell (AHC) inspired by biological hair cells of fish. The sensor consists of a single cilium structure with high aspect ratio and a mechanoreceptor using force sensitive resistor (FSR). The cilium structure is designed for capturing a drag force with direction due to flow field around the sensor and the mechanoreceptor is designed for sensing the drag force with direction from the cilium structure and converting it into an electric signal. The mechanoreceptor has a symmetric four electrodes to sense the drag force and its direction. To fabricate the single cilium structure with high aspect ratio, we have proposed a new design concept using a separated micro mold system (SMS) fabricated by the LIGA process. For a successful replication of the cilium structure, we used the hot embossing process with the help of a double-sided mold system. We used a composite of multiwall carbon nanotube and polydimethylsiloxane (MWCNT-PDMS). The performance of the mechanoreceptors was measured by a computer-controlled nanoindenter. We carried out several experiments with the sensor in the different flow rate and direction using the experimental test apparatus. To calibrate the sensor and calculate the velocity with direction based the signal from the sensor, we analyzed the coupled phenomena between flow field and the cilium structure to calculate the deflection of the cilium structure and the drag force applying to the cilium structure due to the flow field around sensor.

Sorting on the basis of deformability of single cells in a femtosecond laser fabricated optofluidic device

Science.gov (United States)

Bragheri, F.; Paiè, P.; Yang, T.; Nava, G.; Martınez Vázquez, R.; Di Tano, M.; Veglione, M.; Minzioni, P.; Mondello, C.; Cristiani, I.; Osellame, R.

2015-03-01

Optical stretching is a powerful technique for the mechanical phenotyping of single suspended cells that exploits cell deformability as an inherent functional marker. Dual-beam optical trapping and stretching of cells is a recognized tool to investigate their viscoelastic properties. The optical stretcher has the ability to deform cells through optical forces without physical contact or bead attachment. In addition, it is the only method that can be combined with microfluidic delivery, allowing for the serial, high-throughput measurement of the optical deformability and the selective sorting of single specific cells. Femtosecond laser micromachining can fabricate in the same chip both the microfluidic channel and the optical waveguides, producing a monolithic device with a very precise alignment between the components and very low sensitivity to external perturbations. Femtosecond laser irradiation in a fused silica chip followed by chemical etching in hydrofluoric acid has been used to fabricate the microfluidic channels where the cells move by pressure-driven flow. With the same femtosecond laser source two optical waveguides, orthogonal to the microfluidic channel and opposing each other, have been written inside the chip. Here we present an optimized writing process that provides improved wall roughness of the micro-channels allowing high-quality imaging. In addition, we will show results on cell sorting on the basis of mechanical properties in the same device: the different deformability exhibited by metastatic and tumorigenic cells has been exploited to obtain a metastasis-cells enriched sample. The enrichment is verified by exploiting, after cells collection, fluorescence microscopy.

Newly divided eosinophils limit ozone-induced airway hyperreactivity in nonsensitized guinea pigs.

Science.gov (United States)

Wicher, Sarah A; Jacoby, David B; Fryer, Allison D

2017-06-01

Ozone causes vagally mediated airway hyperreactivity and recruits inflammatory cells, including eosinophils, to lungs, where they mediate ozone-induced hyperreactivity 1 day after exposure but are paradoxically protective 3 days later. We aimed to test the role of newly divided eosinophils in ozone-induced airway hyperreactivity in sensitized and nonsensitized guinea pigs. Nonsensitized and sensitized guinea pigs were treated with 5-bromo-2-deoxyuridine (BrdU) to label newly divided cells and were exposed to air or ozone for 4 h. Later (1 or 3 days later), vagally induced bronchoconstriction was measured, and inflammatory cells were harvested from bone marrow, blood, and bronchoalveolar lavage. Ozone induced eosinophil hematopoiesis. One day after ozone, mature eosinophils dominate the inflammatory response and potentiate vagally induced bronchoconstriction. However, by 3 days, newly divided eosinophils have reached the lungs, where they inhibit ozone-induced airway hyperreactivity because depleting them with antibody to IL-5 or a TNF-α antagonist worsened vagally induced bronchoconstriction. In sensitized guinea pigs, both ozone-induced eosinophil hematopoiesis and subsequent recruitment of newly divided eosinophils to lungs 3 days later failed to occur. Thus mature eosinophils dominated the ozone-induced inflammatory response in sensitized guinea pigs. Depleting these mature eosinophils prevented ozone-induced airway hyperreactivity in sensitized animals. Ozone induces eosinophil hematopoiesis and recruitment to lungs, where 3 days later, newly divided eosinophils attenuate vagally mediated hyperreactivity. Ozone-induced hematopoiesis of beneficial eosinophils is blocked by a TNF-α antagonist or by prior sensitization. In these animals, mature eosinophils are associated with hyperreactivity. Thus interventions targeting eosinophils, although beneficial in atopic individuals, may delay resolution of airway hyperreactivity in nonatopic individuals. Copyright �

Investigation of Non-Vacuum Deposition Techniques in Fabrication of Chalcogenide-Based Solar Cell Absorbers

KAUST Repository

Alsaggaf, Ahmed

2015-07-01

The environmental challenges are increasing, and so is the need for renewable energy. For photovoltaic applications, thin film Cu(In,Ga)(S,Se)2 (CIGS) and CuIn(S,Se)2 (CIS) solar cells are attractive with conversion efficiencies of more than 20%. However, the high-efficiency cells are fabricated using vacuum technologies such as sputtering or thermal co-evaporation, which are very costly and unfeasible at industrial level. The fabrication involves the uses of highly toxic gases such as H2Se, adding complexity to the fabrication process. The work described here focused on non-vacuum deposition methods such as printing. Special attention has been given to printing designed in a moving Roll-to-Roll (R2R) fashion. The results show potential of such technology to replace the vacuum processes. Conversion efficiencies for such non-vacuum deposition of Cu(In,Ga)(S,Se)2 solar cells have exceeded 15% using hazardous chemicals such as hydrazine, which is unsuitable for industrial scale up. In an effort to simplify the process, non-toxic suspensions of Cu(In,Ga)S2 molecular-based precursors achieved efficiencies of ~7-15%. Attempts to further simplify the selenization step, deposition of CuIn(S,Se)2 particulate solutions without the Ga doping and non-toxic suspensions of Cu(In,Ga)Se2 quaternary precursors achieved efficiencies (~1-8%). The contribution of this research was to provide a new method to monitor printed structures through spectral-domain optical coherence tomography SD-OCT in a moving fashion simulating R2R process design at speeds up to 1.05 m/min. The research clarified morphological and compositional impacts of Nd:YAG laser heat-treatment on Cu(In,Ga)Se2 absorber layer to simplify the annealing step in non-vacuum environment compatible to R2R. Finally, the research further simplified development methods for CIGS solar cells based on suspensions of quaternary Cu(In,Ga)Se2 precursors and ternary CuInS2 precursors. The methods consisted of post deposition reactive

Fabrication of hybrid solar cells using poly(2,5-dimethoxyaniline) hexagonal structures and zinc oxide nanorods

CSIR Research Space (South Africa)

Mavundla, SE

2012-04-01

Full Text Available crystalline materials with one-dimensional morphology which improves the electron charge transport in the device. A distinctive photoluminescence quenching effect was observed indicating a photo-induced electron transfer. The solar cell devices fabricated from...

Hysteresis data of planar perovskite solar cells fabricated with different solvents.

Science.gov (United States)

Seo, You-Hyun; Kim, Eun-Chong; Cho, Se-Phin; Kim, Seok-Soon; Na, Seok-In

2018-02-01

In this data article, we introduced the hysteresis of planar perovskite solar cells (PSCs) fabricated using dimethylformamide (DMF), gamma-butyrolactone (GBL), methyl-2-pyrrolidinone (NMP), dimethylsulfoxide (DMSO), DMF-DMSO, GBL-DMSO and NMP-DMSO as perovskite precursor solutions according to different scan directions, sweep times, and current stability. The hysteresis analyses of the planar PSCs prepared with a glass-ITO /NiO X /perovskite /PC 61 BM/BCP/Ag configuration were measured with Keithley 2400 source meter unit under 100 mW/cm 2 (AM 1.5 G). The data collected in this article compares the hysteresis of PSCs with different solvents and is directly related to our research article "High-Performance Planar Perovskite Solar Cells: Influence of Solvent upon Performance" (You-Hyun Seo et al., 2017 [1]).

Hysteresis data of planar perovskite solar cells fabricated with different solvents

Directory of Open Access Journals (Sweden)

You-Hyun Seo

2018-02-01

Full Text Available In this data article, we introduced the hysteresis of planar perovskite solar cells (PSCs fabricated using dimethylformamide (DMF, gamma-butyrolactone (GBL, methyl-2-pyrrolidinone (NMP, dimethylsulfoxide (DMSO, DMF-DMSO, GBL-DMSO and NMP-DMSO as perovskite precursor solutions according to different scan directions, sweep times, and current stability. The hysteresis analyses of the planar PSCs prepared with a glass-ITO /NiOX/perovskite /PC61BM/BCP/Ag configuration were measured with Keithley 2400 source meter unit under 100 mW/cm2 (AM 1.5 G. The data collected in this article compares the hysteresis of PSCs with different solvents and is directly related to our research article “High-Performance Planar Perovskite Solar Cells: Influence of Solvent upon Performance” (You-Hyun Seo et al., 2017 [1].

Fabrication of highly porous biodegradable biomimetic nanocomposite as advanced bone tissue scaffold

Directory of Open Access Journals (Sweden)

Abdalla Abdal-hay

2017-02-01

Full Text Available Development of bioinspired or biomimetic materials is currently a challenge in the field of tissue regeneration. In-situ 3D biomimetic microporous nanocomposite scaffold has been developed using a simple lyophilization post hydrothermal reaction for bone healing applications. The fabricated 3D porous scaffold possesses advantages of good bonelike apatite particles distribution, thermal properties and high porous interconnected network structure. High dispersion bonelike apatite nanoparticles (NPs rapidly nucleated and deposited from surrounding biological minerals within chitosan (CTS matrices using hydrothermal technique. After that, freeze-drying method was applied on the composite solution to form the desired porous 3D architecture. Interestingly, the porosity and pore size of composite scaffold were not significantly affected by the particles size and particles content within the CTS matrix. Our results demonstrated that the compression modulus of porous composite scaffold is twice higher than that of plain CTS scaffold, indicating a maximization of the chemical interaction between polymer matrix and apatite NPs. Cytocompatibility test for MC3T3-E1 pre-osteoblasts cell line using MTT-indirect assay test showed that the fabricated 3D microporous nanocomposite scaffold possesses higher cell proliferation and growth than that of pure CTS scaffold. Collectively, our results suggest that the newly developed highly porous apatite/CTS nanocomposite scaffold as an alternative of hydroxyapatite/CTS scaffold may serve as an excellent porous 3D platform for bone tissue regeneration.

Constrained Sintering in Fabrication of Solid Oxide Fuel Cells.

Science.gov (United States)

Lee, Hae-Weon; Park, Mansoo; Hong, Jongsup; Kim, Hyoungchul; Yoon, Kyung Joong; Son, Ji-Won; Lee, Jong-Ho; Kim, Byung-Kook

2016-08-09

Solid oxide fuel cells (SOFCs) are inevitably affected by the tensile stress field imposed by the rigid substrate during constrained sintering, which strongly affects microstructural evolution and flaw generation in the fabrication process and subsequent operation. In the case of sintering a composite cathode, one component acts as a continuous matrix phase while the other acts as a dispersed phase depending upon the initial composition and packing structure. The clustering of dispersed particles in the matrix has significant effects on the final microstructure, and strong rigidity of the clusters covering the entire cathode volume is desirable to obtain stable pore structure. The local constraints developed around the dispersed particles and their clusters effectively suppress generation of major process flaws, and microstructural features such as triple phase boundary and porosity could be readily controlled by adjusting the content and size of the dispersed particles. However, in the fabrication of the dense electrolyte layer via the chemical solution deposition route using slow-sintering nanoparticles dispersed in a sol matrix, the rigidity of the cluster should be minimized for the fine matrix to continuously densify, and special care should be taken in selecting the size of the dispersed particles to optimize the thermodynamic stability criteria of the grain size and film thickness. The principles of constrained sintering presented in this paper could be used as basic guidelines for realizing the ideal microstructure of SOFCs.

Laboratory injection molder for the fabrication of polymeric porous poly-epsilon-caprolactone scaffolds for preliminary mesenchymal stem cells tissue engineering applications

KAUST Repository

Limongi, Tania

2016-12-16

This study presents a simple and rapid fabrication technique involving injection molding and particle leaching (IM/PL) to fabricate the porous scaffold for tissue engineering applications. Sodium chloride (NaCl) and Sucrose are separately mixed with the poly-epsilon-caprolactone (PCL) granules using a screwed thermo regulated extruder, than the biocompatible scaffolds are fabricated through injection molding. The micro/nano structure of the samples and their different grade of porosity were characterized by scanning electron microscopy and mercury intrusion porosimetry. Bone marrow-derived mesenchymal stem cells are chose to cell culture and Hoechst 33342 staining was used to verify the biocompatibility of the polymeric porous surfaces. We concluded that, by using the same fast solvent free injection/leaching process, the use of Sucrose as porogen, instead of NaCl, allowed the obtainment of biocompatible scaffolds with a higher grade of porosity with suitable cell adhesion capacity for tissue engineering purpose.

How to prevent contamination with Candida albicans during the fabrication of transplantable oral mucosal epithelial cell sheets

Directory of Open Access Journals (Sweden)

Ryo Takagi

2015-06-01

Full Text Available We have utilized patients' own oral mucosa as a cell source for the fabrication of transplantable epithelial cell sheets to treat limbal stem cell deficiency and mucosal defects after endoscopic submucosal dissection of esophageal cancer. Because there are abundant microbiotas in the human oral cavity, the oral mucosa was sterilized and 40 μg/mL gentamicin and 0.27 μg/mL amphotericin B were added to the culture medium in our protocol. Although an oral surgeon carefully checked each patient's oral cavity and although candidiasis was not observed before taking the biopsy, contamination with Candida albicans (C. albicans was detected in the conditioned medium during cell sheet fabrication. After adding 1 μg/mL amphotericin B to the transportation medium during transport from Nagasaki University Hospital to Tokyo Women's Medical University, which are 1200 km apart, no proliferation of C. albicans was observed. These results indicated that the supplementation of transportation medium with antimycotics would be useful for preventing contamination with C. albicans derived from the oral mucosa without hampering cell proliferation.

Design, fabrication and performance of a mixed-reactant membraneless micro direct methanol fuel cell stack

Science.gov (United States)

Abrego-Martínez, J. C.; Moreno-Zuria, A.; Cuevas-Muñiz, F. M.; Arriaga, L. G.; Sun, Shuhui; Mohamedi, Mohamed

2017-12-01

In the present work, we report the design, fabrication and evaluation of a membraneless mixed-reactant and air-breathing microfluidic direct methanol fuel cell (ML-μDMFC) stack operated in passive mode. The operation under mixed-reactant conditions was achieved by using a highly methanol-tolerant Ag/Pt/CP cathode with ultra-low Pt loading in alkaline medium. Prior to the fabrication of the stack, a flow simulation was made in order to study the behavior of the reactants stream in the microchannel through the 2 cells. Subsequently, the device was tested in passive mode using a mixture of 5 M MeOH +0.5 M KOH. The results showed that by connecting the 2 cells in series, it is possible to effectively double the voltage of a single ML-μDMFC, as well as increasing the absolute power by 75% with practically no cost increase. The stack was capable of operate continuously for more than 2 h with a single charge of 40 μL, producing an OCV of 0.89 V and a maximum power density of 3.33 mW mgPt-1. Additionally, the device exhibited good stability throughout a 10 h test.

Design, fabrication and performance evaluation of an integrated reformed methanol fuel cell for portable use

Science.gov (United States)

Zhang, Shubin; Zhang, Yufeng; Chen, Junyu; Yin, Congwen; Liu, Xiaowei

2018-06-01

In this paper, an integrated reformed methanol fuel cell (RMFC) as a portable power source is designed, fabricated and tested. The RMFC consists of a methanol steam reformer (MSR), a high temperature proton exchange membrane fuel cell (HT-PEMFC) stack, a microcontroller unit (MCU) and other auxiliaries. First, a system model based on Matlab/Simulink is established to investigate the mass and energy transport characteristics within the whole system. The simulation results suggest a hydrogen flow rate of at least 670 sccm is needed for the system to output 30 W and simultaneously maintain thermal equilibrium. Second, a metallic MSR and an HT-PEMFC stack with 12 cells are fabricated and tested. The tests show that the RMFC system is able to function normally when the performances of all the components meet the minimum requirements. At last, in the experiment of successfully powering a laptop, the RMFC system exhibits a stable performance during the complete work flow of all the phases, namely start-up, output and shutdown. Moreover, with a conservative design of 20 W power rating, maximum energy conversion efficiency of the RMFC system can be achieved (36%), and good stability in long-term operation is shown.

Fabrication of a zirconia MEMS-based microthruster by gel casting on PDMS soft molds

International Nuclear Information System (INIS)

Cheah, K H; Khiew, P S; Chin, J K

2012-01-01

A zirconia microelectromechanical-system-based microthruster was fabricated through a newly developed fabrication route. Gel casting of homogenously dispersed zirconia suspension on polydimethylsiloxane soft mold was utilized to replicate the geometries of microthruster design onto a ceramic layer of about 1.2 mm thick. Lamination of the patterned ceramic layer to another flat ceramic layer and subsequent sintering produced the microthruster. Characterizations on the fabricated prototype showed good shape retention on the replicated geometries and good quality of lamination. Shrinkage of about 10–15% was noted after sintering. The current fabrication route is particularly promising for the development of high-performance micropropulsion systems which require their structural material to survive in an extreme environment which is corrosive, of high temperature and highly oxidative. (paper)

A laser-based technology for fabricating a soda-lime glass based microfluidic device for circulating tumour cell capture.

Science.gov (United States)

Nieto, Daniel; Couceiro, Ramiro; Aymerich, Maria; Lopez-Lopez, Rafael; Abal, Miguel; Flores-Arias, María Teresa

2015-10-01

We developed a laser-based technique for fabricating microfluidic microchips on soda-lime glass substrates. The proposed methodology combines a laser direct writing, as a manufacturing tool for the fabrication of the microfluidics structures, followed by a post-thermal treatment with a CO2 laser. This treatment will allow reshaping and improving the morphological (roughness) and optical qualities (transparency) of the generated microfluidics structures. The use of lasers commonly implemented for material processing makes this technique highly competitive when compared with other glass microstructuring approaches. The manufactured chips were tested with tumour cells (Hec 1A) after being functionalized with an epithelial cell adhesion molecule (EpCAM) antibody coating. Cells were successfully arrested on the pillars after being flown through the device giving our technology a translational application in the field of cancer research. Copyright © 2015 Elsevier B.V. All rights reserved.

Facile moldless fabrication of disk-shaped and reed blood cell-like microparticles using photopolymerization of tripropylene glycol diacrylate

International Nuclear Information System (INIS)

Choi, Jongchul; Won, June; Song, Simon

2014-01-01

A facile method for the moldless fabrication of 2- or 3-dimensional microparticles is proposed by using a photopolymerization technique. Using only a monomer solution of tripropylene glycol diacrylate, a film mask and standard UV lithography equipment, we were able to fabricate microparticles of various shapes, such as disks, dimpled disks similar in shape to red blood cells, and slender gourd shapes, unlike previous moldless fabrication techniques requiring expensive and/or sophisticated equipment. The simple method could produce more than one million particles in a single batch, indicating that it can be applied to the mass production of polymer microparticles. Analyses of scanning electron micrographs and optical micrographs of the microparticles indicated that their size distribution was highly monodisperse. Detailed fabrication processes and statistics on the microparticle sizes are given in this paper. (technical note)

New polymorphous computing fabric

International Nuclear Information System (INIS)

Wolinski, Christophe; Gokhale, Maya; McCabe, Kevin P.

2002-01-01

This paper introduces a new polymorphous computing Fabric well suited to DSP and Image Processing and describes its implementation on a Configurable System on a Chip (CSOC). The architecture is highly parameterized and enables customization of the synthesized Fabric to achieve high performance for a specific class of application. For this reason it can be considered to be a generic model for hardware accelerator synthesis from a high level specification. Another important innovation is the Fabric uses a global memory concept, which gives the host processor random access to all the variables and instructions on the Fabric. The Fabric supports different computing models including MIMD, SPMD and systolic flow and permits dynamic reconfiguration. We present a specific implementation of a bank of FIR filters on a Fabric composed of 52 cells on the Altera Excalibur ARM running at 33 MHz. The theoretical performance of this Fabric is 1.8 GMACh. For the FIR application we obtain 1.6 GMAC/s real performance. Some automatic tools have been developed like the tool to provide a host access utility and assembler.

Fabricating solid carbon porous electrodes from powders

Science.gov (United States)

Kaschmitter, James L.; Tran, Tri D.; Feikert, John H.; Mayer, Steven T.

1997-01-01

Fabrication of conductive solid porous carbon electrodes for use in batteries, double layer capacitors, fuel cells, capacitive dionization, and waste treatment. Electrodes fabricated from low surface area (Electrodes having a higher surface area, fabricated from powdered carbon blacks, such as carbon aerogel powder, carbon aerogel microspheres, activated carbons, etc. yield high conductivity carbon compositives with excellent double layer capacity, and can be used in double layer capacitors, or for capacitive deionization and/or waste treatment of liquid streams. By adding metallic catalysts to be high surface area carbons, fuel cell electrodes can be produced.

Dye-sensitized solar cells with ZnO nanoparticles fabricated at low temperature

Energy Technology Data Exchange (ETDEWEB)

Cho, Sungjae; Moon, Byungjoon; Son, Dongick [Korea Institute of Science and Technology, Wanju (Korea, Republic of); Kwon, Byoungwook; Choi, Wonkook [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

2014-11-15

The authors investigated the microstructural and the electrical properties of ZnO based dyesensitized solar cells (DSSCs) fabricated using a low-temperature-processed(200 .deg. C) dye-sensitized ZnO-nanoparticle thin film and a Pt catalyst deposited on ITO/glass by using RF magnetron sputtering. A hydropolymer containing PEG (poly(ethylene glycol)) and PEO (poly ethylene oxide) was used to make uniformly-distributed ZnO nanoparticle layer that form a nano-porous ZnO network after heat treatment and was then dye sensitized and sandwiched between two electrodes in an electrolyte to make a DSSC device. The highest measured parameters, the short circuit current density (J{sub sc}), the open circuit potential(V{sub oc}), the fill factor(FF), and the power conversion efficiency (η), of the DSSC fabricated under optimized conditions were observed to be 4.93 mA/cm{sup 2}, 0.56 V, 0.40, and 1.12%, respectively.

Fabrication of polymer/cadmium sulfide hybrid solar cells [P3HT:CdS and PCPDTBT:CdS] by spray deposition.

Science.gov (United States)

Kumar, Neetesh; Dutta, Viresh

2014-11-15

This paper investigates fabrication of surfactant free CdS nanoparticles (NPs) and application in the fabrication of P3HT:CdS and PCPDTBT:CdS bulk-heterojunction hybrid solar cells using high-throughput, large-area, low cost spray deposition technique. Both the hybrid active layers and hole transport layers are deposited by spray technique. The CdS/Poly(3-hexylthiophene-2,5-diyl) (P3HT) and CdS/Poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) hybrid devices are fabricated by spray deposition process at optimized conditions (i.e. film thickness, spray solution volume, distance between sample and spray nozzle, substrate temperature, etc.). The power conversion efficiency of η=0.6% and 1.02% is obtained for P3HT:CdS and PCPDTBT:CdS hybrid devices, respectively. Spray coating holds significant promise as a technique capable of fabricating large-area, high performance hybrid solar cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Fabrication and characterization of a cell electrostimulator device combining physical vapor deposition and laser ablation

Science.gov (United States)

Aragón, Angel L.; Pérez, Eliseo; Pazos, Antonio; Bao-Varela, Carmen; Nieto, Daniel

2017-08-01

In this work we present the process of fabrication and optimization of a prototype of a cell electrostimulator device for medical application combining physical vapor deposition and laser ablation. The fabrication of the first prototype begins with a deposition of a thin layer of 200 nm of aluminium on a borosilicate glass substrate using physical vapor deposition (PVD). In the second stage the geometry design of the electrostimulator is made in a CAD-like software available in a Nd:YVO4 Rofin Power line 20E, operating at the fundamental wavelength of 1064 nm and 20 ns pulse width. Choosing the proper laser parameters the negative of the electrostimulator desing is ablated. After that the glass is assembled between two polycarbonate sheets and a thick sheet of polydimethylsiloxane (PDMS). The PDMS sheet has a round hole in where cells are placed. There is also included a thin soda-lime silicate glass (100 μm) between the electrostimulator and the PMDS to prevent the cells for being in contact with the electric circuit. In order to control the electrical signal applied to the electrostimulator is used a digital I/O device from National Instruments (USB-6501) which provides 5 V at the output monitored by a software programmed in LabVIEW. Finally, the optical and electrical characterization of the cell electrostimulator device is presented.

Fabrication of Pillar Shaped Electrode Arrays for Artificial Retinal Implants

Directory of Open Access Journals (Sweden)

Sung June Kim

2008-09-01

Full Text Available Polyimide has been widely applied to neural prosthetic devices, such as the retinal implants, due to its well-known biocompatibility and ability to be micropatterned. However, planar films of polyimide that are typically employed show a limited ability in reducing the distance between electrodes and targeting cell layers, which limits site resolution for effective multi-channel stimulation. In this paper, we report a newly designed device with a pillar structure that more effectively interfaces with the target. Electrode arrays were successfully fabricated and safely implanted inside the rabbit eye in suprachoroidal space. Optical Coherence Tomography (OCT showed well-preserved pillar structures of the electrode without damage. Bipolar stimulation was applied through paired sites (6:1 and the neural responses were successfully recorded from several regions in the visual cortex. Electrically evoked cortical potential by the pillar electrode array stimulation were compared to visual evoked potential under full-field light stimulation.

Study and fabrication of solid oxide fuel cells through tape casting and co-sintering

International Nuclear Information System (INIS)

Grosjean, A.

2004-11-01

This work is dedicated to the devising of a low-cost fabrication process of solid oxide fuel cells (SOFC). Technical requirements impose the shaping method: stripe casting as well as the materials used: Yttria-stabilized zirconia (YSZ), nickel and lanthanum manganite doped with strontium (LSM). In order to comply with environmental requirements the developed process uses an aqueous barbotine solvent. We get electrodes and the electrolyte separately, the use of an absorbent drying process has enabled us to join 3 layers to form an elementary cell with great interfacial homogeneity. The resistance of the cell to sintering has been improved through the symmetrization of the deformations of the cell. In order to interpret the low electrical properties of the cell and its quick damaging, transmission microscopy studies have been performed. These studies have shown 2 facts. First, 2 isolating phases appear at the cathode (at the LSM/YSZ interface) because of a too high sintering temperature and secondly, a quick clustering of nickel grains appears during cell operation that leads to a local loss of the nickel grid percolation. This problem has been solved by increasing the size of nickel oxide grains from 0.5 μm to 3 μm) to stabilize the microstructure. The issue of the reactivity at the LSM/YSZ interfaces was tackled in 2 different ways, we have tried to lower the sintering temperature by using a zirconia nano-powder first and then by replacing zirconia in the electrolyte by gadolinium-doped ceria. The use of zirconia nano-powder has failed to decrease sintering temperature while preserving the electrolyte density and the use of ceria has triggered instabilities that have not yet been solved. Despite all these drawbacks, this process allows the fabrication of an excellent anode/electrolyte interface. (A.C.)

Newly synthesized bis-benzimidazole compound 8 induces apoptosis, autophagy and reactive oxygen species generation in HeLa cells.

Science.gov (United States)

Chu, Naying; Yao, Guodong; Liu, Yuan; Cheng, Maosheng; Ikejima, Takashi

2016-09-01

Compound 8 (C8) is a newly synthesized bis-benzimidazole derivative and exerts significant anti-tumor activity in vitro. Previous studies demonstrated that C8 induced apoptosis and autophagy in human promyelocytic leukemia HL60 cells. However, cytotoxicity study on human peripheral blood mononuclear cells (hPBMC) showed that C8 exhibited less toxicity in normal cells. In this study, the molecular mechanism of C8 on human cervical carcinoma HeLa cells was investigated. The results showed that C8 inhibited the growth of HeLa cells and triggered both apoptotic and autophagic cell death. Subsequent experiment also indicated that reactive oxygen species (ROS) generation was induced in C8-treated HeLa cells. Since ROS scavenger decreased the ratio of apoptotic and autophagic cells, ROS generation contributed to C8-induced apoptosis and autophagy. Furthermore, inhibitors of apoptosis and autophagy also reduced ROS generation, respectively. Autophagy inhibition increased cell growth compared to C8-treated group and attenuated apoptotic cell death, indicating that C8-induced autophagy promoted apoptosis for cell death. However, the percentage of autophagic cells was enhanced when limiting apoptosis process. Taken together, C8 induced ROS-mediated apoptosis and autophagy in HeLa cells, autophagy promoted apoptosis but the former was antagonized by the latter. The data also gave us a new perspective on the anti-tumor effect of C8. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mechanical properties and cell-culture characteristics of a polycaprolactone kagome-structure scaffold fabricated by a precision extruding deposition system.

Science.gov (United States)

Lee, Se-Hwan; Cho, Yong Sang; Hong, Myoung Wha; Lee, Bu-Kyu; Park, Yongdoo; Park, Sang-Hyug; Kim, Young Yul; Cho, Young-Sam

2017-09-13

To enhance the mechanical properties of three-dimensional (3D) scaffolds used for bone regeneration in tissue engineering, many researchers have studied their structure and chemistry. In the structural engineering field, the kagome structure has been known to have an excellent relative strength. In this study, to enhance the mechanical properties of a synthetic polymer scaffold used for tissue engineering, we applied the 3D kagome structure to a porous scaffold for bone regeneration. Prior to fabricating the biocompatible-polymer scaffold, the ideal kagome structure, which was manufactured by a 3D printer of the digital light processing type, was compared with a grid-structure, which was used as the control group, using a compressive experiment. A polycaprolactone (PCL) kagome-structure scaffold was successfully fabricated by additive manufacturing using a 3D printer with a precision extruding deposition head. To assess the physical characteristics of the fabricated PCL-kagome-structure scaffold, we analyzed its porosity, pore size, morphological structure, surface roughness, compressive stiffness, and mechanical bending properties. The results showed that, the mechanical properties of proposed kagome-structure scaffold were superior to those of a grid-structure scaffold. Moreover, Sarcoma osteogenic (Saos-2) cells were used to evaluate the characteristics of in vitro cell proliferation. We carried out cell counting kit-8 (CCK-8) and DNA contents assays. Consequently, the cell proliferation of the kagome-structure scaffold was increased; this could be because the surface roughness of the kagome-structure scaffold enhances initial cell attachment.

Fabrication of Nanostructured Poly-ε-caprolactone 3D Scaffolds for 3D Cell Culture Technology

KAUST Repository

Schipani, Rossana

2015-04-21

Tissue engineering is receiving tremendous attention due to the necessity to overcome the limitations related to injured or diseased tissues or organs. It is the perfect combination of cells and biomimetic-engineered materials. With the appropriate biochemical factors, it is possible to develop new effective bio-devices that are capable to improve or replace biological functions. Latest developments in microfabrication methods, employing mostly synthetic biomaterials, allow the production of three-dimensional (3D) scaffolds that are able to direct cell-to-cell interactions and specific cellular functions in order to drive tissue regeneration or cell transplantation. The presented work offers a rapid and efficient method of 3D scaffolds fabrication by using optical lithography and micro-molding techniques. Bioresorbable polymer poly-ε-caprolactone (PCL) was the material used thanks to its high biocompatibility and ability to naturally degrade in tissues. 3D PCL substrates show a particular combination in the designed length scale: cylindrical shaped pillars with 10μm diameter, 10μm height, arranged in a hexagonal lattice with spacing of 20μm were obtained. The sidewalls of the pillars were nanostructured by attributing a 3D architecture to the scaffold. The suitability of these devices as cell culture technology supports was evaluated by plating NIH/3T3 mouse embryonic fibroblasts and human Neural Stem Cells (hNSC) on them. Scanning Electron Microscopy (SEM) analysis was carried out in order to examine the micro- and nano-patterns on the surface of the supports. In addition, after seeding of cells, SEM and immunofluorescence characterization of the fabricated systems were performed to check adhesion, growth and proliferation. It was observed that cells grow and develop healthy on the bio-polymeric devices by giving rise to well-interconnected networks. 3D PCL nano-patterned pillared scaffold therefore may have considerable potential as effective tool for

Critical analysis of stability and performance of organometal halide perovskite solar cells via various fabrication method (Review

Directory of Open Access Journals (Sweden)

Suhaimi Suriati

2017-01-01

Full Text Available Organometal halide perovskite solar cells (Omh-PSCs have attracted attention due to its unique electrical and optical properties. Ideally, the Omh-PSCs should remain free from degradation under normal operating conditions for several years, preferably tens of years. In order to produce high power conversion efficiency with low potential of degradation, different fabrication methods have been developed. The reported stability of perovskite films can vary significantly and reported to decay substantially up to 20% of its original performance. A thorough understanding of fabrication process upon the stability of the device is regarded as crucial to pave the way for future endeavors. This review summarized and highlighted the recent research of fabrication methods that gave an impact to the stability of perovskite devices.

High-performance micro-solid oxide fuel cells fabricated on nanoporous anodic aluminum oxide templates

Energy Technology Data Exchange (ETDEWEB)

Kwon, Chang-Woo; Kim, Hyun-Mi; Kim, Ki-Bum [WCUHybrid Materials Program, Department of Materials Science and Engineering, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul, 151-742 (Korea, Republic of); Son, Ji-Won; Lee, Jong-Ho; Lee, Hae-Weon [High Temperature Energy Materials Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul, 136-791 (Korea, Republic of)

2011-03-22

Micro-solid oxide fuel cells ({mu}-SOFCs) are fabricated on nanoporous anodic aluminum oxide (AAO) templates with a cell structure composed of a 600-nm-thick AAO free-standing membrane embedded on a Si substrate, sputter-deposited Pt electrodes (cathode and anode) and an yttria-stabilized zirconia (YSZ) electrolyte deposited by pulsed laser deposition (PLD). Initially, the open circuit voltages (OCVs) of the AAO-supported {mu}-SOFCs are in the range of 0.05 V to 0.78 V, which is much lower than the ideal value, depending on the average pore size of the AAO template and the thickness of the YSZ electrolyte. Transmission electron microscopy (TEM) analysis reveals the formation of pinholes in the electrolyte layer that originate from the porous nature of the underlying AAO membrane. In order to clog these pinholes, a 20-nm thick Al{sub 2}O{sub 3} layer is deposited by atomic layer deposition (ALD) on top of the 300-nm thick YSZ layer and another 600-nm thick YSZ layer is deposited after removing the top intermittent Al{sub 2}O{sub 3} layer. Fuel cell devices fabricated in this way manifest OCVs of 1.02 V, and a maximum power density of 350 mW cm{sup -2} at 500 C. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Dewetting based fabrication of fibrous micro-scaffolds as potential injectable cell carriers.

Science.gov (United States)

Song, Hokyung; Yin, Liya; Chilian, William M; Zhang Newby, Bi-Min

2015-03-01

Although regenerative medicine utilizing tissue scaffolds has made enormous strides in recent years, many constraints still hamper their effectiveness. A limitation of many scaffolds is that they form surface patches, which are not particularly effective for some types of "wounds" that are deep within tissues, e.g., stroke and myocardial infarction. In this study, we reported the generation of fibrous micro-scaffolds feasible for delivering cells by injection into the tissue parenchyma. The micro-scaffolds (widthsdewetting of poly(lactic-co-glycolic acid) thin films containing parallel strips, and cells were seeded to form cell/polymer micro-constructs during or post the micro-scaffold fabrication process. Five types of cells including rat induced vascular progenitor cells were assessed for the formation of the micro-constructs. Critical factors in forming fibrous micro-scaffolds via dewetting of polymer thin films were found to be properties of polymers and supporting substrates, temperature, and proteins in the culture medium. Also, the ability of cells to attach to the micro-scaffolds was essential in forming cell/polymer micro-constructs. Both in vitro and in vivo assessments of injecting these micro-scaffolding constructs showed, as compared to free cells, enhanced cell retention at the injected site, which could lead to improved tissue engineering and regeneration. Copyright © 2014 Elsevier B.V. All rights reserved.

Fabrication of elliptical SRF cavities

Science.gov (United States)

Singer, W.

2017-03-01

The technological and metallurgical requirements of material for high-gradient superconducting cavities are described. High-purity niobium, as the preferred metal for the fabrication of superconducting accelerating cavities, should meet exact specifications. The content of interstitial impurities such as oxygen, nitrogen, and carbon must be below 10 μg g-1. The hydrogen content should be kept below 2 μg g-1 to prevent degradation of the quality factor (Q-value) under certain cool-down conditions. The material should be free of flaws (foreign material inclusions or cracks and laminations) that can initiate a thermal breakdown. Traditional and alternative cavity mechanical fabrication methods are reviewed. Conventionally, niobium cavities are fabricated from sheet niobium by the formation of half-cells by deep drawing, followed by trim machining and electron beam welding. The welding of half-cells is a delicate procedure, requiring intermediate cleaning steps and a careful choice of weld parameters to achieve full penetration of the joints. A challenge for a welded construction is the tight mechanical and electrical tolerances. These can be maintained by a combination of mechanical and radio-frequency measurements on half-cells and by careful tracking of weld shrinkage. The main aspects of quality assurance and quality management are mentioned. The experiences of 800 cavities produced for the European XFEL are presented. Another cavity fabrication approach is slicing discs from the ingot and producing cavities by deep drawing and electron beam welding. Accelerating gradients at the level of 35-45 MV m-1 can be achieved by applying electrochemical polishing treatment. The single-crystal option (grain boundary free) is discussed. It seems that in this case, high performance can be achieved by a simplified treatment procedure. Fabrication of the elliptical resonators from a seamless pipe as an alternative is briefly described. This technology has yielded good

Fabrication and characterization of DBM/p-Si heterojunction solar cell

International Nuclear Information System (INIS)

El-Nahass, M.M.; Kamel, M.A.; Atta, A.A.; Huthaily, S.Y.

2013-01-01

Hybrid organic/inorganic solar cell was fabricated by depositing a thin film of p-N,N dimethylaminobenzylidenemalononitrile (DBM) onto p-Si substrate. DBM is a donor–acceptor disubstituted benzenes dye known as molecular rotors and highly polar molecular compounds. Its powder has a polycrystalline structure, while nano-crystallite rods are formed in the as-deposited film. The dark current density–voltage (J–V) characteristics of Au/DBM/p-Si/Al heterojunction device measured at different temperatures ranging from 291 to 353 K have been investigated. The operating conduction mechanisms, the series and shunt resistances, the rectification ratio, the ideality factor, the effective barrier height, and the total trap concentration were determined. The capacitance–voltage (C–V) characteristics indicated that the junction is of abrupt nature. The built-in voltage and the carrier concentration distributed through the depletion region were estimated. Under illumination, the DBM/p-Si cell showed photovoltaic properties and the photovoltaic parameters were evaluated. -- Highlights: ► The molecular rotors DBM dye can be used to manufacture D/A solar cells. ► Since D/A are situated in the DBM molecule, we ensure photoinduced D → A electron transfer. ► The DBM film is grown as nano-rods. ► The most of the DBM bulk of the cell contributes to the generation of external current.

Fabrication and characterization of DBM/p-Si heterojunction solar cell

Energy Technology Data Exchange (ETDEWEB)

El-Nahass, M.M.; Kamel, M.A. [Physics Department, Faculty of Education, Ain Shams University, Roxy, 11757 Cairo (Egypt); Atta, A.A. [Physics Department, Faculty of Education, Ain Shams University, Roxy, 11757 Cairo (Egypt); Physics Department, Faculty of Science, Taif University, Taif, 888 Taif (Saudi Arabia); Huthaily, S.Y., E-mail: s_huthaily@yahoo.com [Physics Department, Faculty of Education, Hodeidah University, Alduraihimi, 3114 Hodeidah (Yemen)

2013-01-15

Hybrid organic/inorganic solar cell was fabricated by depositing a thin film of p-N,N dimethylaminobenzylidenemalononitrile (DBM) onto p-Si substrate. DBM is a donor-acceptor disubstituted benzenes dye known as molecular rotors and highly polar molecular compounds. Its powder has a polycrystalline structure, while nano-crystallite rods are formed in the as-deposited film. The dark current density-voltage (J-V) characteristics of Au/DBM/p-Si/Al heterojunction device measured at different temperatures ranging from 291 to 353 K have been investigated. The operating conduction mechanisms, the series and shunt resistances, the rectification ratio, the ideality factor, the effective barrier height, and the total trap concentration were determined. The capacitance-voltage (C-V) characteristics indicated that the junction is of abrupt nature. The built-in voltage and the carrier concentration distributed through the depletion region were estimated. Under illumination, the DBM/p-Si cell showed photovoltaic properties and the photovoltaic parameters were evaluated. -- Highlights: Black-Right-Pointing-Pointer The molecular rotors DBM dye can be used to manufacture D/A solar cells. Black-Right-Pointing-Pointer Since D/A are situated in the DBM molecule, we ensure photoinduced D {yields} A electron transfer. Black-Right-Pointing-Pointer The DBM film is grown as nano-rods. Black-Right-Pointing-Pointer The most of the DBM bulk of the cell contributes to the generation of external current.

Fabrication of Aligned Carbon Nanotube/Polycaprolactone/Gelatin Nanofibrous Matrices for Schwann Cell Immobilization

Directory of Open Access Journals (Sweden)

Shiao-Wen Tsai

2014-01-01

Full Text Available In this study, we utilized a mandrel rotating collector consisting of two parallel, electrically conductive pieces of tape to fabricate aligned electrospun polycaprolactone/gelatin (PG and carbon nanotube/polycaprolactone/gelatin (PGC nanofibrous matrices. Furthermore, we examined the biological performance of the PGC nanofibrous and film matrices using an in vitro culture of RT4-D6P2T rat Schwann cells. Using cell adhesion tests, we found that carbon nanotube inhibited Schwann cell attachment on PGC nanofibrous and film matrices. However, the proliferation rates of Schwann cells were higher when they were immobilized on PGC nanofibrous matrices compared to PGC film matrices. Using western blot analysis, we found that NRG1 and P0 protein expression levels were higher for cells immobilized on PGC nanofibrous matrices compared to PG nanofibrous matrices. However, the carbon nanotube inhibited NRG1 and P0 protein expression in cells immobilized on PGC film matrices. Moreover, the NRG1 and P0 protein expression levels were higher for cells immobilized on PGC nanofibrous matrices compared to PGC film matrices. We found that the matrix topography and composition influenced Schwann cell behavior.

Constrained Sintering in Fabrication of Solid Oxide Fuel Cells

Science.gov (United States)

Lee, Hae-Weon; Park, Mansoo; Hong, Jongsup; Kim, Hyoungchul; Yoon, Kyung Joong; Son, Ji-Won; Lee, Jong-Ho; Kim, Byung-Kook

2016-01-01

Solid oxide fuel cells (SOFCs) are inevitably affected by the tensile stress field imposed by the rigid substrate during constrained sintering, which strongly affects microstructural evolution and flaw generation in the fabrication process and subsequent operation. In the case of sintering a composite cathode, one component acts as a continuous matrix phase while the other acts as a dispersed phase depending upon the initial composition and packing structure. The clustering of dispersed particles in the matrix has significant effects on the final microstructure, and strong rigidity of the clusters covering the entire cathode volume is desirable to obtain stable pore structure. The local constraints developed around the dispersed particles and their clusters effectively suppress generation of major process flaws, and microstructural features such as triple phase boundary and porosity could be readily controlled by adjusting the content and size of the dispersed particles. However, in the fabrication of the dense electrolyte layer via the chemical solution deposition route using slow-sintering nanoparticles dispersed in a sol matrix, the rigidity of the cluster should be minimized for the fine matrix to continuously densify, and special care should be taken in selecting the size of the dispersed particles to optimize the thermodynamic stability criteria of the grain size and film thickness. The principles of constrained sintering presented in this paper could be used as basic guidelines for realizing the ideal microstructure of SOFCs. PMID:28773795

Fabrication of Monolithic Dye-Sensitized Solar Cell Using Ionic Liquid Electrolyte

Directory of Open Access Journals (Sweden)

Seigo Ito

2012-01-01

Full Text Available To improve the durability of dye-sensitized solar cells (DSCs, monolithic DSCs with ionic liquid electrolyte were studied. Deposited by screen printing, a carbon layer was successfully fabricated that did not crack or peel when annealing was employed beforehand. Optimized electrodes exhibited photovoltaic characteristics of 0.608 V open-circuit voltage, 6.90 cm−2 mA short-circuit current, and 0.491 fill factor, yielding 2.06% power conversion efficiency. The monolithic DSC using ionic liquid electrolyte was thermally durable and operated stably for 1000 h at 80°C.

Porous SiO_2 nanofiber grafted novel bioactive glass–ceramic coating: A structural scaffold for uniform apatite precipitation and oriented cell proliferation on inert implant

International Nuclear Information System (INIS)

Das, Indranee; De, Goutam; Hupa, Leena; Vallittu, Pekka K.

2016-01-01

A composite bioactive glass–ceramic coating grafted with porous silica nanofibers was fabricated on inert glass to provide a structural scaffold favoring uniform apatite precipitation and oriented cell proliferation. The coating surfaces were investigated thoroughly before and after immersion in simulated body fluid. In addition, the proliferation behavior of fibroblast cells on the surface was observed for several culture times. The nanofibrous exterior of this composite bioactive coating facilitated homogeneous growth of flake-like carbonated hydroxyapatite layer within a short period of immersion. Moreover, the embedded porous silica nanofibers enhanced hydrophilicity which is required for proper cell adhesion on the surface. The cells proliferated well following a particular orientation on the entire coating by the assistance of nanofibrous scaffold-like structural matrix. This newly engineered composite coating was effective in creating a biological structural matrix favorable for homogeneous precipitation of calcium phosphate, and organized cell growth on the inert glass surface. - Highlights: • Fabricated porous SiO_2 nanofibers grafted composite bioactive glass–ceramic coating on inert glass. • The newly engineered coating facilitates uniformly dense apatite precipitation. • Embedded porous silica nanofibers enhance hydrophilicity of the coated surface. • Cells proliferate well on the entire coating following a particular orientation by the assistance of nanofibers. • The coatings have potential to be used as biological scaffold on the surface of implants.

High-temperature fabrication of Ag(In,Ga)Se{sub 2} thin films for applications in solar cells

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xianfeng [International Center for Science and Engineering Programs, Waseda University, Tokyo (Japan); Yamada, Akira [Department of Physical Electronics, Tokyo Institute of Technology, Tokyo (Japan); Kobayashi, Masakazu [Department of Electrical Engineering and Bioscience, Waseda University, Tokyo (Japan); Kagami Memorial Research Institute for Materials Science, Waseda University, Tokyo (Japan)

2017-10-15

Molecular beam epitaxy was used to fabricate Ag(In,Ga)Se{sub 2} (AIGS) thin films. To improve the diffusion of Ag, high-temperature deposition and high-temperature annealing methods were applied to fabricate AIGS films. The as-grown AIGS thin films were then used to make AIGS solar cells. We found that grain size and crystallinity of AIGS films were considerably improved by increasing the deposition and annealing temperature. For high-temperature deposition, temperatures over 600 C led to decomposition of the AIGS film, desorption of In, and deterioration of its crystallinity. The most appropriate deposition temperature was 590 C and a solar cell with a power conversion efficiency of 4.1% was obtained. High-temperature annealing of the AIGS thin films showed improved crystallinity as annealing temperature was increased and film decomposition and In desorption were prevented. A solar cell based on this film showed the highest conversion efficiency of 6.4% when annealed at 600 C. When the annealing temperature was further increased to 610 C, the performance of the cell deteriorated due to loss of the out-of-plane Ga gradient. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Fabrication of hydrogels with steep stiffness gradients for studying cell mechanical response.

Directory of Open Access Journals (Sweden)

Raimon Sunyer

Full Text Available Many fundamental cell processes, such as angiogenesis, neurogenesis and cancer metastasis, are thought to be modulated by extracellular matrix stiffness. Thus, the availability of matrix substrates having well-defined stiffness profiles can be of great importance in biophysical studies of cell-substrate interaction. Here, we present a method to fabricate biocompatible hydrogels with a well defined and linear stiffness gradient. This method, involving the photopolymerization of films by progressively uncovering an acrylamide/bis-acrylamide solution initially covered with an opaque mask, can be easily implemented with common lab equipment. It produces linear stiffness gradients of at least 115 kPa/mm, extending from ∼1 kPa to 240 kPa (in units of Young's modulus. Hydrogels with less steep gradients and narrower stiffness ranges can easily be produced. The hydrogels can be covalently functionalized with uniform coatings of proteins that promote cell adhesion. Cell spreading on these hydrogels linearly correlates with hydrogel stiffness, indicating that this technique effectively modifies the mechanical environment of living cells. This technique provides a simple approach that produces steeper gradients, wider rigidity ranges, and more accurate profiles than current methods.

Complete Procedure for Fabrication of a Fused Silica Ultrarapid Microfluidic Mixer Used in Biophysical Measurements

Directory of Open Access Journals (Sweden)

Dena Izadi

2017-01-01

Full Text Available In this paper we present a method to fabricate a fused silica microfluidic device by employing low viscosity KMPR photoresists. The resulting device is a continuous-flow microfluidic mixer based on hydrodynamic focusing. The advantages of this new fabrication method compared to the traditional approach using a poly-silicon mask are simplification, and time and cost reduction, while still preserving the quality and the performance of the mixers. This process results in devices in which the focusing channel has an aspect ratio of 10:1. The newly-fabricated mixer is successfully used to observe the folding of the Pin1 WW domain at the microsecond time scale.

Testing of a cathode fabricated by painting with a brush pen for anode-supported tubular solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Liu, Renzhu; Zhao, Chunhua; Li, Junliang; Wang, Shaorong; Wen, Zhaoyin; Wen, Tinglian [CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050 (China)

2010-01-15

We have studied the properties of a cathode fabricated by painting with a brush pen for use with anode-supported tubular solid oxide fuel cells (SOFCs). The porous cathode connects well with the electrolyte. A preliminary examination of a single tubular cell, consisting of a Ni-YSZ anode support tube, a Ni-ScSZ anode functional layer, a ScSZ electrolyte film, and a LSM-ScSZ cathode fabricated by painting with a brush pen, has been carried out, and an improved performance is obtained. The ohmic resistance of the cathode side clearly decreases, falling to a value only 37% of that of the comparable cathode made by dip-coating at 850 C. The single cell with the painted cathode generates a maximum power density of 405 mW cm{sup -2} at 850 C, when operating with humidified hydrogen. (author)

Porous SiO{sub 2} nanofiber grafted novel bioactive glass–ceramic coating: A structural scaffold for uniform apatite precipitation and oriented cell proliferation on inert implant

Energy Technology Data Exchange (ETDEWEB)

Das, Indranee [Nano-Structured Materials Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032 (India); De, Goutam, E-mail: gde@cgcri.res.in [Nano-Structured Materials Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032 (India); Hupa, Leena [Johan Gadolin Process Chemistry Centre, Åbo Akademi University, FI-20500 Åbo (Finland); Vallittu, Pekka K. [Turku Clinical Biomaterials Centre—TCBC, University of Turku, FI-20520 Turku (Finland); Institute of Dentistry, University of Turku, Department of Biomaterials Science and City of Turku, Welfare Division, Turku (Finland)

2016-05-01

A composite bioactive glass–ceramic coating grafted with porous silica nanofibers was fabricated on inert glass to provide a structural scaffold favoring uniform apatite precipitation and oriented cell proliferation. The coating surfaces were investigated thoroughly before and after immersion in simulated body fluid. In addition, the proliferation behavior of fibroblast cells on the surface was observed for several culture times. The nanofibrous exterior of this composite bioactive coating facilitated homogeneous growth of flake-like carbonated hydroxyapatite layer within a short period of immersion. Moreover, the embedded porous silica nanofibers enhanced hydrophilicity which is required for proper cell adhesion on the surface. The cells proliferated well following a particular orientation on the entire coating by the assistance of nanofibrous scaffold-like structural matrix. This newly engineered composite coating was effective in creating a biological structural matrix favorable for homogeneous precipitation of calcium phosphate, and organized cell growth on the inert glass surface. - Highlights: • Fabricated porous SiO{sub 2} nanofibers grafted composite bioactive glass–ceramic coating on inert glass. • The newly engineered coating facilitates uniformly dense apatite precipitation. • Embedded porous silica nanofibers enhance hydrophilicity of the coated surface. • Cells proliferate well on the entire coating following a particular orientation by the assistance of nanofibers. • The coatings have potential to be used as biological scaffold on the surface of implants.

Fabrication of dye-sensitized solar cell (DSSC) using annato seeds (Bixa orellana Linn)

Energy Technology Data Exchange (ETDEWEB)

Haryanto, Ditia Allindira; Landuma, Suarni; Purwanto, Agus [Department of Chemical Engineering, Sebelas Maret University, Surakarta 632112 (Indonesia)

2014-02-24

The Fabrication of dye sensitized solar cell (DSSC) using Annato seeds has been conducted in this study. Annato seeds (Bixa orellana Linn) used as a sensitizer for dye sensitized solar cell. The experimental parameter was concentration of natural dye. Annato seeds was extracted using etanol solution and the concentration was controlled by varying mass of Annato seeds. A semiconductor TiO{sub 2} was prepared by a screen printing method for coating glass use paste of TiO{sub 2}. Construction DSSC used layered systems (sandwich) consists of working electrode (TiO{sub 2} semiconductor-dye) and counter electrode (platina). Both are placed on conductive glass and electrolytes that occur electrons cycle. The characterization of thin layer of TiO{sub 2} was conducted using SEM (Scanning Electron Microscpy) analysis showed the surface morphology of TiO{sub 2} thin layer and the cross section of a thin layer of TiO{sub 2} with a thickness of 15–19 μm. Characterization of natural dye extract was determined using UV-Vis spectrometry analysis shows the wavelength range annato seeds is 328–515 nm, and the voltage (V{sub oc}) and electric current (I{sub sc}) resulted in keithley test for 30 gram, 40 gram, and 50 gram were 0,4000 V; 0,4251 V; 0,4502 V and 0,000074 A; 0,000458 A; 0,000857 A, respectively. The efficiencies of the fabricated solar cells using annato seeds as senstizer for each varying mass are 0,00799%, 0,01237%, and 0,05696%.

Fabrication of contacts for silicon solar cells including printing burn through layers

Science.gov (United States)

Ginley, David S; Kaydanova, Tatiana; Miedaner, Alexander; Curtis, Calvin J; Van Hest, Marinus Franciscus Antonius Maria

2014-06-24

A method for fabricating a contact (240) for a solar cell (200). The method includes providing a solar cell substrate (210) with a surface that is covered or includes an antireflective coating (220). For example, the substrate (210) may be positioned adjacent or proximate to an outlet of an inkjet printer (712) or other deposition device. The method continues with forming a burn through layer (230) on the coating (220) by depositing a metal oxide precursor (e.g., using an inkjet or other non-contact printing method to print or apply a volume of liquid or solution containing the precursor). The method includes forming a contact layer (240) comprising silver over or on the burn through layer (230), and then annealing is performed to electrically connect the contact layer (240) to the surface of the solar cell substrate (210) through a portion of the burn through layer (230) and the coating (220).

Fabrication of nanostructured ZnO film as a hole-conducting layer of organic photovoltaic cell

Science.gov (United States)

Kim, Hyomin; Kwon, Yiseul; Choe, Youngson

2013-05-01

We have investigated the effect of fibrous nanostructured ZnO film as a hole-conducting layer on the performance of polymer photovoltaic cells. By increasing the concentration of zinc acetate dihydrate, the changes of performance characteristics were evaluated. Fibrous nanostructured ZnO film was prepared by sol-gel process and annealed on a hot plate. As the concentration of zinc acetate dihydrate increased, ZnO fibrous nanostructure grew from 300 to 600 nm. The obtained ZnO nanostructured fibrous films have taken the shape of a maze-like structure and were characterized by UV-visible absorption, scanning electron microscopy, and X-ray diffraction techniques. The intensity of absorption bands in the ultraviolet region was increased with increasing precursor concentration. The X-ray diffraction studies show that the ZnO fibrous nanostructures became strongly (002)-oriented with increasing concentration of precursor. The bulk heterojunction photovoltaic cells were fabricated using poly(3-hexylthiophene-2,5-diyl) and indene-C60 bisadduct as active layer, and their electrical properties were investigated. The external quantum efficiency of the fabricated device increased with increasing precursor concentration.

Design and fabrication of a high performance inorganic tandem solar cell with 11.5% conversion efficiency

International Nuclear Information System (INIS)

Amiri, Omid; Mir, Noshin; Ansari, Fatemeh; Salavati-Niasari, Masoud

2017-01-01

Tandem solar cell is a design that combines two types of solar cells to benefit their advantages. We show a new concept for achieving highly efficient dye sensitized and quantum dot tandem solar cells. The new tandem cell further enhances the performance of the device, leading to a power conversion efficiency more than 11% under 1.5 Air Mass. To the best of our knowledge, this is the first time that the efficiency over 11 percent is achieved based on tandem solar cell. X-ray diffraction, Transmission Electron Microscopy, Scanning Electron Microscopy, Current-Voltage measurments, Intensity modulated photocurrent spectroscopy, intensity modulated photovoltage spectroscopy, Energy Dispersive X-ray spectroscopy, Brunauer-Emmett-Teller, Barrett-Joyner-Halenda and absorption spectroscopy were used to characterize the fabricated solar cells.

A multi-level capacitor-less memory cell fabricated on a nano-scale strained silicon-on-insulator

International Nuclear Information System (INIS)

Park, Jea-Gun; Kim, Seong-Je; Shin, Mi-Hee; Song, Seung-Hyun; Shim, Tae-Hun; Chung, Sung-Woong; Enomoto, Hirofumi

2011-01-01

A multi-level capacitor-less memory cell was fabricated with a fully depleted n-metal-oxide-semiconductor field-effect transistor on a nano-scale strained silicon channel on insulator (FD sSOI n-MOSFET). The 0.73% biaxial tensile strain in the silicon channel of the FD sSOI n-MOSFET enhanced the effective electron mobility to ∼ 1.7 times that with an unstrained silicon channel. This thereby enables both front- and back-gate cell operations, demonstrating eight-level volatile memory-cell operation with a 1 ms retention time and 12 μA memory margin. This is a step toward achieving a terabit volatile memory cell.

Fabrication of the superferric cyclotron gas-stopper magnet at NSCL at Michigan state university

International Nuclear Information System (INIS)

Chouhan, S S; Bollen, G; DeKamp, J; Green, M A; Magsig, C; Zeller, A F; Lawton, D; Morrissey, D J; Ottarson, J; Schwarz, S

2014-01-01

The magnet for the cyclotron gas stopper is a newly designed, large warm-iron superconducting cyclotron sector gradient dipole. The maximum field in the centre (gap = 0.18 m) is 2.7 T. The outer diameter of magnet yoke is 4.0 m, with a pole radius of 1.1 m and B * ρ = 1.8 T m. The fabrication and assembly of the iron return yoke and twelve pole pieces is complete. Separate coils are mounted on the return yokes that have a total mass of about 167 metric tons of iron. This paper illustrates the design and the fabrication process for the cyclotron gas-stopper magnet that is being fabricated at MSU.

The effects of fabrication temperature on current-voltage characteristics and energy efficiencies of quantum dot sensitized ZnOH-GO hybrid solar cells

International Nuclear Information System (INIS)

Islam, S. M. Z.; Gayen, Taposh; Tint, Naing; Alfano, Robert; Shi, Lingyan; Seredych, Mykola; Bandosz, Teresa J.

2014-01-01

The effects of fabrication temperature are investigated on the performance of CdSe quantum dot (QD)-sensitized hybrid solar cells of the composite material of zinc (hydr)oxide (ZnOH-GO)with 2 wt. % graphite oxide. The current-voltage (I-V) and photo-current measurements show that higher fabrication temperatures yield greater photovoltaic power conversion efficiencies that essentially indicate more efficient solar cells. Two Photon Fluorescence images show the effects of temperature on the internal morphologies of the solar devices based on such materials. The CdSe-QD sensitized ZnOH-GO hybrid solar cells fabricated at 450 °C showing conversion of ∼10.60% under a tungsten lamp (12.1 mW/cm 2 ) are reported here, while using potassium iodide as an electrolyte. The output photocurrent, I (μA) with input power, P (mW/cm 2 ) is found to be superlinear, showing a relation of I = P n , where n = 1.4.

Ultrasonic Substrate Vibration-Assisted Drop Casting (SVADC) for the Fabrication of Photovoltaic Solar Cell Arrays and Thin-Film Devices.

Science.gov (United States)

Eslamian, Morteza; Zabihi, Fatemeh

2015-12-01

A simple, low-cost, versatile, and potentially scalable casting method is proposed for the fabrication of micro- and nano-thin films, herein termed as ultrasonic "substrate vibration-assisted drop casting" (SVADC). The impingement of a solution drop onto a substrate in a simple process called drop casting, usually results in spreading of the liquid solution and the formation of a non-uniform thin solid film after solvent evaporation. Our previous and current supporting results, as well as few similar reports by others, confirm that imposing ultrasonic vibration on the substrate can simply convert the uncontrollable drop casting method into a controllable coating technique. Therefore, the SVADC may be used to fabricate an array of emerging thin-film solar cells, such as polymer, perovskite, and quantum-dot solar cells, as well as other small thin-film devices, in a roll-to-roll and automated fabrication process. The preliminary results demonstrate a ten-fold increase in electrical conductivity of PSS made by SVADC compared with the film made by conventional drop casting. Also, simple planar perovskite solar cells made here using SVADC show promising performance with an efficiency of over 3 % for a simple structure without performing process optimization or using expensive materials and treatments.

Fabrication of NaYF4:Yb,Er Nanoprobes for Cell Imaging Directly by Using the Method of Hydrion Rivalry Aided by Ultrasonic.

Science.gov (United States)

Li, Zhihua; Miao, Haixia; Fu, Ying; Liu, Yuxiang; Zhang, Ran; Tang, Bo

2016-12-01

A novel method of fabricating water-soluble bio-probes with ultra-small size such as NaYF 4 :Yb,Er (18 nm), NaGdF 4 :Yb,Er (8 nm), CaF 2 :Yb,Er (10 nm), PbS (7 nm), and ZnS (12 nm) has been developed to provide for the solubility switch of nanoparticles from oil-soluble to water-soluble in terms of hydrion rivalry aided by ultrasonic. Using NaYF 4 :Yb,Er (18 nm) as an example, we evaluate the properties of as-prepared water-soluble nanoparticles (NPs) by using thermogravimetric analyses (TGA), Fourier transform infrared spectroscopy (FTIR), zeta potential (ζ) testing, and 1H nuclear magnetic resonance ( 1 HNMR). The measured ζ value shows that the newly prepared hydrophilic NaYF 4 :Yb,Er NPs are the positively charged particles. Acting as reactive electrophilic moiety, the freshly prepared hydrophilic NaYF 4 :Yb,Er NPs have carried out the coupling with amino acids and fluorescence labeling and imaging of HeLa cells directly. Experiments indicate that the method of hydrion rivalry aided by ultrasonic provides a simple and novel opportunity to transform hydrophobic NPs into hydrophilic NPs with good reactivity, which can be imaging some specific biological targets directly.

Size and frequency of gaps in newly synthesized DNA of xeroderma pigmentosum human cells irradiated with ultraviolet light

International Nuclear Information System (INIS)

Meneghini, R.; Cordeiro-Stone, M.; Schumacher, R.I.

1981-01-01

Native newly synthesized DNA from human cells (xeroderma pigmentosum type) irradiated with ultraviolet light releases short pieces of DNA (L-DNA) when incubated with the single-strand specific S 1 nuclease. This is not observed in the case of unirradiated cells. Previous experiments had shown that the L-DNA resulted from the action of S 1 nuclease upon gaps, i.e., single-stranded DNA discontinuities in larger pieces of double-stranded DNA. We verified that the duplex L-DNA, that arises from the inter-gap regions upon S 1 nuclease treatment, has a size which approximates the distance between two pyrimidine dimers on the same strand. A method was devised to measure the size of the gaps. These parameters have been considered in the proposition of a model for DNA synthesis on a template containing pyrimidine dimers

Predictive value of pretreatment positron emission tomography/computed tomography in patients with newly diagnosed extranodal natural killer/T-cell lymphoma.

Science.gov (United States)

Bai, Bing; Huang, Hui-Qiang; Cai, Qi-Chun; Fan, Wei; Wang, Xiao-Xiao; Zhang, Xu; Lin, Ze-Xiao; Gao, Yan; Xia, Yun-Fei; Guo, Ying; Cai, Qing-Qing; Jiang, Wen-Qi; Lin, Tong-Yu

2013-03-01

The role of (18)Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in extranodal natural killer/T-cell lymphoma (ENKL) is not well established. This study aimed to investigate the prognostic role of the pretreatment maximum standardized uptake value (SUV(max)) on PET/CT in patients with newly diagnosed ENKL. Among 364 consecutive patients with newly diagnosed ENKL, 81 patients were included and reviewed. The impact of SUV(max) on survival and the relationship between SUV(max) and other clinicopathological parameters were analyzed. The median SUV(max) was 14.6 (range 2.0-45.4). The optimal cutoff value of SUV(max) to predict overall survival (OS) was 15. Patients with high SUV(max) (SUVmax >15) were associated with bulky disease (P KPI, P = 0.046), resistance to primary treatment (P = 0.014), poor OS (P 60 years (P = 0.001), stage III-IV (P = 0.023), SUV(max) >15 (P = 0.020), and bulky disease (>5 cm) (P = 0.002). By using the SUV(max), patients in most subgroups stratified by the KPI or the International Prognostic Index (IPI) were further discriminated in OS with significant statistical difference. Our results suggest the pretreatment SUV(max) is predictive of prognosis in patients with newly diagnosed ENKL. The SUV(max) may provide additional prognostic information for IPI and KPI.

Structural Component Fabrication and Characterization of Advanced Radiation Resistant ODS Steel for Next Generation Nuclear Systems

International Nuclear Information System (INIS)

Noh, Sang Hoon; Kim, Young Chun; Jin, Hyun Ju; Choi, Byoung Kwon; Kang, Suk Hoon; Kim, Tae Kyu

2016-01-01

In a sodium-cooled fast reactor (SFR), the coolant outlet temperature and peak temperature of the fuel cladding tube will be about 545 .deg. C and 700 .deg. C with 250 dpa of a very high neutron dose rate. To realize this system, it is necessary to develop an advanced structural material having high creep and irradiation resistance at high temperatures. Austenitic stainless steel may be one of the candidates because of good strength and corrosion resistance at the high temperatures, however irradiation swelling severely occurred to 120dpa at high temperatures and this eventually leads to a decrease of the mechanical properties and dimensional stability. Advanced radiation resistant ODS steel (ARROS) has been newly developed for the in-core structural components in SFR, which has very attractive microstructures to achieve both superior creep and radiation resistances at high temperatures [4]. Nevertheless, the use of ARROS as a structural material essentially requires the fabrication technology development for component parts such as sheet, plate and tube. In this study, plates and tubes were tentatively fabricated with a newly developed alloy, ARROS. Microstructures as well as mechanical properties were also investigated to determine the optimized condition of the fabrication processes.

Fabrication of ultrahigh density metal-cell-metal crossbar memory devices with only two cycles of lithography and dry-etch procedures

KAUST Repository

Zong, Baoyu

2013-05-20

A novel approach to the fabrication of metal-cell-metal trilayer memory devices was demonstrated by using only two cycles of lithography and dry-etch procedures. The fabricated ultrahigh density crossbar devices can be scaled down to ≤70 nm in half-pitch without alignment issues. Depending on the different dry-etch mechanisms in transferring high and low density nanopatterns, suitable dry-etch angles and methods are studied for the transfer of high density nanopatterns. Some novel process methods have also been developed to eliminate the sidewall and other conversion obstacles for obtaining high density of uniform metallic nanopatterns. With these methods, ultrahigh density trilayer crossbar devices (∼2 × 1010 bit cm-2-kilobit electronic memory), which are composed of built-in practical magnetoresistive nanocells, have been achieved. This scalable process that we have developed provides the relevant industries with a cheap means to commercially fabricate three-dimensional high density metal-cell-metal nanodevices. © 2013 IOP Publishing Ltd.

Analysis of mechanical fabrication experience with CEBAF's production SRF cavities

International Nuclear Information System (INIS)

Mammosser, J.; Kneisel, P.; Benesch, J.

1993-06-01

CEBAF has received a total of 360 five-cell niobium cavities, the largest group of industrially fabricated superconducting cavities so far. An extensive data base exists on the fabrication, surface treatment, assembly and cavity performance parameters. Analysis of the mechanical features of the cavities includes the following: the spread in fabrication tolerances of the cells derived from field profiles of the ''as fabricated'' cavities and the ''as fabricated'' external Q-values of the fundamental power coupler compared to dimensional deviations. A comparison is made of the pressure sensitivity of cavities made of materials from different manufacturers between 760 torr (4.2 K) and 23 torr (2 K)

Roll-coating fabrication of flexible large area small molecule solar cells with power conversion efficiency exceeding 1%

DEFF Research Database (Denmark)

Liu, Wenqing; Liu, Shiyong; Zawacka, Natalia Klaudia

2014-01-01

All solution-processed flexible large area small molecule bulk heterojunction solar cells were fabricated via roll-coating technology. Our devices were produced from slot-die coating on a lab-scale mini roll-coater under ambient conditions without the use of spin-coating or vacuum evaporation.......01%, combined with an open circuit voltage of 0.73 V, a short-circuit current density of 3.13 mA cm (2) and a fill factor of 44% were obtained for the device with SM1, which was the first example reported for efficient roll-coating fabrication of flexible large area small molecule solar cells with PCE exceeding...... methods. Four diketopyrrolopyrrole based small molecules (SMs 1-4) were utilized as electron donors with (6,6)phenyl- C61-butyric acid methyl ester as an acceptor and their photovoltaic performances based on roll-coated devices were investigated. The best power conversion efficiency (PCE) of 1...

Fabrication and Photovoltaic Characteristics of Coaxial Silicon Nanowire Solar Cells Prepared by Wet Chemical Etching

Directory of Open Access Journals (Sweden)

Chien-Wei Liu

2012-01-01

Full Text Available Nanostructured solar cells with coaxial p-n junction structures have strong potential to enhance the performances of the silicon-based solar cells. This study demonstrates a radial junction silicon nanowire (RJSNW solar cell that was fabricated simply and at low cost using wet chemical etching. Experimental results reveal that the reflectance of the silicon nanowires (SNWs declines as their length increases. The excellent light trapping was mainly associated with high aspect ratio of the SNW arrays. A conversion efficiency of ∼7.1% and an external quantum efficiency of ∼64.6% at 700 nm were demonstrated. Control of etching time and diffusion conditions holds great promise for the development of future RJSNW solar cells. Improving the electrode/RJSNW contact will promote the collection of carries in coaxial core-shell SNW array solar cells.

Quantum dot sensitized solar cells fabricated by means of a novel inorganic spinel nanoparticle

Science.gov (United States)

Jalali-Moghadam, Elnaz; Shariatinia, Zahra

2018-05-01

A novel inorganic spinel compound with formula Zn0.5184La0.7859Ce0.3994Al1.0026O4 (ZLCA) was synthesized by the gel combustion method and its exact formula was approved by the XPS analysis. The TEM image exhibited that the ZLCA NPs were very fine, spherical and slightly agglomerated particles with their particle size changed in the range of ∼5-20 nm. Then, several quantum dot-sensitized solar cells (QDSSCs) were fabricated using this new compound which was doped into the TiO2 pastes of photoanodes and subsequently the CdS, CdS and ZnS layers were deposited on the ZLCA-doped TiO2 layer by the SILAR and the CBD methods. Results indicated that the photovoltaic parameters of the optimized cell (η = 3.50%, JSC = 11.690 mA·cm-2) were boosted compared with those of the reference cell which was free of ZLCA NPs (η = 2.14%, JSC = 7.075 mA·cm-2) indicating rather high improvements of approximately 64 and 65% in the efficiency and short-circuit current density, respectively. The UV-Vis absorption spectra of all nanocomposite photoanodes revealed broad absorption bands between ∼320 and 600 nm. The lowest intensity of the photoluminescence peak for the CdSe cell fabricated using 0.6%ZLCA suggested that it had the least charge recombination and the easiest electron transfer which was confirmed by the J-V and efficiency results. The Electrochemical impedance spectra (EIS) illustrated that the charge transfer resistances (RCT) of cells were dropped by addition of the ZLCA into the TiO2 compared with that of the cell made without using ZLCA NPs. The RCT resistance was 1900 Ω for pure TiO2 but it was decreased to 81.6 Ω in the optimized cell containing 0.6%wt of ZLCA. Thus, it could be decided that doping 0.6%wt ZLCA was appropriate to attain suitable photocurrent efficiency for the QDSSCs because it was used in a minimum quantity to accelerate the electron transport, decrease the recombination and increase the cell efficiency.

Bioorthogonal Chemistry for the Isolation and Study of Newly Synthesized Histones and Their Modifications.

Science.gov (United States)

Arnaudo, Anna M; Link, A James; Garcia, Benjamin A

2016-03-18

The nucleosome is an octamer containing DNA wrapped around one histone H3-H4 tetramer and two histone H2A-H2B dimers. Within the nucleosome, histones are decorated with post-translational modifications. Previous studies indicate that the H3-H4 tetramer is conserved during DNA replication, suggesting that old tetramers serve as a template for the modification of newly synthesized tetramers. Here, we present a method that merges bioorthogonal chemistry with mass spectrometry for the study of modifications on newly synthesized histones in mammalian cells. HeLa S3 cells are dually labeled with the methionine analog azidohomoalanine and heavy (13)C6,(15)N4 isotope labeled arginine. Heavy amino acid labeling marks newly synthesized histones while azidohomoalanine incorporation allows for their isolation using bioorthogonal ligation. Labeled mononucleosomes were covalently linked via a copper catalyzed reaction to a FLAG-GGR-alkyne peptide, immunoprecipitated, and subjected to mass spectrometry for quantitative modification analysis. Mononucleosomes containing new histones were successfully isolated using this approach. Additionally, the development of this method highlights the potential deleterious effects of azidohomoalanine labeling on protein PTMs and cell cycle progression, which should be considered for future studies utilizing bioorthogonal labeling strategies in mammalian cells.

In Vitro Evaluation of Essential Mechanical Properties and Cell Behaviors of a Novel Polylactic-co-Glycolic Acid (PLGA-Based Tubular Scaffold for Small-Diameter Vascular Tissue Engineering

Directory of Open Access Journals (Sweden)

Nuoxin Wang

2017-07-01

Full Text Available In this paper, we investigate essential mechanical properties and cell behaviors of the scaffolds fabricated by rolling polylactic-co-glycolic acid (PLGA electrospinning (ES films for small-diameter vascular grafts (inner diameter < 6 mm. The newly developed strategy can be used to fabricate small diameter vascular grafts with or without pre-seeded cells, which are two main branches for small diameter vascular engineering. We demonstrate that the mechanical properties of our rolling-based scaffolds can be tuned flexibly by the number of layers. For cell-free scaffolds, with the increase of layer number, burst pressure and suture retention increase, elastic tensile modulus maintains unchanged statistically, but compliance and liquid leakage decrease. For cell-containing scaffolds, seeding cells will significantly decrease the liquid leakage, but there are no statistical differences for other mechanical properties; moreover, cells live and proliferate well in the scaffold after a 6-day culture.

Absorption spectra of localized surface plasmon resonance observed in an inline/picoliter spectrometer cell fabricated by a near ultraviolet femtosecond laser

Science.gov (United States)

Shiraishi, Masahiko; Nishiyama, Michiko; Watanabe, Kazuhiro; Kubodera, Shoichi

2018-03-01

Absorption spectra based on localized surface plasmon resonance (LSPR) were obtained with an inline/picoliter spectrometer cell. The spectrometer cell was fabricated into an optical glass fiber by focusing a near UV (NUV) femtosecond laser pulses at a wavelength of 400 nm with an energy of 30 μJ. The laser beam was focused from two directions opposite to each other to fabricate a through-hole spectrometer cell. A diameter of the cell was approximately 3 μm, and the length was approximately 62.5 μm, which was nearly equal to the core diameter of the optical fiber. Liquid solution of gold nanoparticles (GNPs) with a diameter of 5-10 nm was injected into the spectrometer cell with its volume of 0.4 pL. The absorption peak centered at 518 nm was observed. An increase of absorption associated with the increase of the number of nanoparticles was in agreement with the numerical calculation based on the Lambert-Beer law.

Development and fabrication of a new concept planar-tubular solid oxide fuel cell (PT-SOFC)

Energy Technology Data Exchange (ETDEWEB)

Chen, Y.; Chen, F. [CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, 230026 Anhui (China); Department of Mechanical Engineering, University of South Carolina, 300 Main Street, Columbia, SC 29208 (United States); Ding, D. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Gao, J. [CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, 230026 Anhui (China)

2011-06-15

The paper reports a new concept of planar-tubular solid oxide fuel cell (PT-SOFC). Emphasis is on the fabrication of the required complex configuration of Ni-yttria-stabilised zirconia (YSZ) porous anode support by tert-butyl alcohol (TBA) based gelcasting, particularly the effects of solid loading, amounts of monomers and dispersant on the rheological behaviour of suspension, the shrinkage of a wet gelcast green body upon drying, and the properties of final sample after sintering at 1350 C and reduction from NiO-YSZ to Ni-YSZ. The results show that the gelcasting is a powerful method for preparation of the required complex configuration anode support. The anode support resulted from an optimised suspension with the solid loading of 25 vol% has uniform microstructure with 37% porosity, bending strength of 44 MPa and conductivity of 300 S cm{sup -} {sup 1} at 700 C, meeting the requirements for an anode support of SOFC. Based on the as-prepared anode support, PT-SOFC single cell of Ni-YSZ/YSZ/LSCF has been fabricated by slurry coating and co-sintering technique. The cell peak power density reaches 63, 106 and 141 mW cm {sup -} {sup 2} at 700, 750 and 800 C, respectively, using hydrogen as fuel and ambient air as oxidant. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

SRF Cavity Fabrication and Materials

Energy Technology Data Exchange (ETDEWEB)

Singer, W [DESY (Germany)

2014-07-01

The technological and metallurgical requirements of material for highgradient superconducting cavities are described. High-purity niobium, as the preferred metal for the fabrication of superconducting accelerating cavities, should meet exact specifications. The content of interstitial impurities such as oxygen, nitrogen, and carbon must be below 10μg/g. The hydrogen content should be kept below 2μg/g to prevent degradation of the Q-value under certain cool-down conditions. The material should be free of flaws (foreign material inclusions or cracks and laminations) that can initiate a thermal breakdown. Defects may be detected by quality control methods such as eddy current scanning and identified by a number of special methods. Conventional and alternative cavity fabrication methods are reviewed. Conventionally, niobium cavities are fabricated from sheet niobium by the formation of half-cells by deep drawing, followed by trim machining and Electron-Beam Welding (EBW). The welding of half-cells is a delicate procedure, requiring intermediate cleaning steps and a careful choice of weld parameters to achieve full penetration of the joints. The equator welds are particularly critical. A challenge for a welded construction is the tight mechanical and electrical tolerances. These can be maintained by a combination of mechanical and radio-frequency measurements on halfcells and by careful tracking of weld shrinkage. The established procedure is suitable for large series production. The main aspects of quality assurance management are mentioned. Another cavity fabrication approach is slicing discs from the ingot and producing cavities by deep drawing and EBW. Accelerating gradients at the level of 35–45 MV·m–1 can be achieved by applying Electropolishing (EP) treatment. Furthermore, the single-crystal option (grain boundary free) is promising. It seems that in this case, high performance can be achieved by a simplified treatment procedure. Fabrication of the

Neural Cell Chip Based Electrochemical Detection of Nanotoxicity.

Science.gov (United States)

Kafi, Md Abdul; Cho, Hyeon-Yeol; Choi, Jeong Woo

2015-07-02

Development of a rapid, sensitive and cost-effective method for toxicity assessment of commonly used nanoparticles is urgently needed for the sustainable development of nanotechnology. A neural cell with high sensitivity and conductivity has become a potential candidate for a cell chip to investigate toxicity of environmental influences. A neural cell immobilized on a conductive surface has become a potential tool for the assessment of nanotoxicity based on electrochemical methods. The effective electrochemical monitoring largely depends on the adequate attachment of a neural cell on the chip surfaces. Recently, establishment of integrin receptor specific ligand molecules arginine-glycine-aspartic acid (RGD) or its several modifications RGD-Multi Armed Peptide terminated with cysteine (RGD-MAP-C), C(RGD)₄ ensure farm attachment of neural cell on the electrode surfaces either in their two dimensional (dot) or three dimensional (rod or pillar) like nano-scale arrangement. A three dimensional RGD modified electrode surface has been proven to be more suitable for cell adhesion, proliferation, differentiation as well as electrochemical measurement. This review discusses fabrication as well as electrochemical measurements of neural cell chip with particular emphasis on their use for nanotoxicity assessments sequentially since inception to date. Successful monitoring of quantum dot (QD), graphene oxide (GO) and cosmetic compound toxicity using the newly developed neural cell chip were discussed here as a case study. This review recommended that a neural cell chip established on a nanostructured ligand modified conductive surface can be a potential tool for the toxicity assessments of newly developed nanomaterials prior to their use on biology or biomedical technologies.

Neural Cell Chip Based Electrochemical Detection of Nanotoxicity

Directory of Open Access Journals (Sweden)

Md. Abdul Kafi

2015-07-01

Full Text Available Development of a rapid, sensitive and cost-effective method for toxicity assessment of commonly used nanoparticles is urgently needed for the sustainable development of nanotechnology. A neural cell with high sensitivity and conductivity has become a potential candidate for a cell chip to investigate toxicity of environmental influences. A neural cell immobilized on a conductive surface has become a potential tool for the assessment of nanotoxicity based on electrochemical methods. The effective electrochemical monitoring largely depends on the adequate attachment of a neural cell on the chip surfaces. Recently, establishment of integrin receptor specific ligand molecules arginine-glycine-aspartic acid (RGD or its several modifications RGD-Multi Armed Peptide terminated with cysteine (RGD-MAP-C, C(RGD4 ensure farm attachment of neural cell on the electrode surfaces either in their two dimensional (dot or three dimensional (rod or pillar like nano-scale arrangement. A three dimensional RGD modified electrode surface has been proven to be more suitable for cell adhesion, proliferation, differentiation as well as electrochemical measurement. This review discusses fabrication as well as electrochemical measurements of neural cell chip with particular emphasis on their use for nanotoxicity assessments sequentially since inception to date. Successful monitoring of quantum dot (QD, graphene oxide (GO and cosmetic compound toxicity using the newly developed neural cell chip were discussed here as a case study. This review recommended that a neural cell chip established on a nanostructured ligand modified conductive surface can be a potential tool for the toxicity assessments of newly developed nanomaterials prior to their use on biology or biomedical technologies.

A newly isolated probiotic Enterococcus faecalis strain from vagina microbiota enhances apoptosis of human cancer cells.

Science.gov (United States)

Nami, Y; Abdullah, N; Haghshenas, B; Radiah, D; Rosli, R; Yari Khosroushahi, A

2014-08-01

This study aimed to describe probiotic properties and bio-therapeutic effects of newly isolated Enterococcus faecalis from the human vaginal tract. The Enterococcus faecalis strain was originally isolated from the vaginal microbiota of Iranian women and was molecularly identified using 16SrDNA gene sequencing. Some biochemical methodologies were preliminarily used to characterize the probiotic potential of Ent. faecalis, including antibiotic susceptibility, antimicrobial activity, as well as acid and bile resistance. The bio-therapeutic effects of this strain's secreted metabolites on four human cancer cell lines (AGS, HeLa, MCF-7 and HT-29) and one normal cell line (HUVEC) were evaluated by cytotoxicity assay and apoptosis scrutiny. The characterization results demonstrated into the isolated bacteria strain revealed probiotic properties, such as antibiotic susceptibility, antimicrobial activity and resistance under conditions similar to those in the gastrointestinal tract. Results of bio-therapeutic efficacy assessments illustrated acceptable apoptotic effects on four human cancer cell lines and negligible side effects on assayed normal cell line. Our findings revealed that the apoptotic effect of secreted metabolites mainly depended on proteins secreted by Ent. faecalis on different cancer cells. These proteins can induce the apoptosis of cancer cells. The metabolites produced by this vaginal Ent. faecalis strain can be used as alternative pharmaceutical compounds with promising therapeutic indices because they are not cytotoxic to normal mammalian cells. Accordingly, the physicochemical, structural and functional properties of the secreted anticancer substances should be further investigated before using them as anticancer therapeutics. This study aim to screen total bacterial secreted metabolites as a wealthy source to find the new active compounds to introduce as anticancer therapeutics in the future. © 2014 The Society for Applied Microbiology.

SRF Cavity Fabrication and Materials

CERN Document Server

Singer, W

2014-07-17

The technological and metallurgical requirements of material for highgradient superconducting cavities are described. High-purity niobium, as the preferred metal for the fabrication of superconducting accelerating cavities, should meet exact specifications. The content of interstitial impurities such as oxygen, nitrogen, and carbon must be below 10μg/g. The hydrogen content should be kept below 2μg/g to prevent degradation of the Q-value under certain cool-down conditions. The material should be free of flaws (foreign material inclusions or cracks and laminations) that can initiate a thermal breakdown. Defects may be detected by quality control methods such as eddy current scanning and identified by a number of special methods. Conventional and alternative cavity fabrication methods are reviewed. Conventionally, niobium cavities are fabricated from sheet niobium by the formation of half-cells by deep drawing, followed by trim machining and Electron-Beam Welding (EBW). The welding of half-cells is a delicate...

Fabrication, Tuning, Treatment and Testing of Two 3.5 Cell Photo-Injector Cavities for the ELBE Linac

International Nuclear Information System (INIS)

Arnold, A.; Murcek, P.; Teichert, J.; Xiang, R.; Eremeev, G. V.; Kneisel, P.; Stirbet, M.; Turlington, L.

2011-01-01

As part of a CRADA (Cooperative Research and Development Agreement) between Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and Thomas Jefferson Lab National Accelerator Facility (TJNAF) we have fabricated and tested two 1.3 GHz 3.5 cell photo-injector cavities from polycrystalline RRR niobium and large grain RRR niobium, respectively. The cavity with the better performance will replace the presently used injector cavity in the ELBE linac. The cavities have been fabricated and pre-tuned at TJNAF, while the more sophisticated final field tuning, the adjustment of the external couplings and the field profile measurement of transverse electric modes for RF focusing was done at HZDR. The following standard surface treatment and the vertical test was carried out at TJNAF's production facilities. A major challenge turned out to be the rinsing of the cathode cell, which has small opening (O-slash10mm) to receive the cathode stalk. Another unexpected problem encountered after etching, since large visible defects appeared in the least accessible cathode cell. This contribution reports about our experiences, initial results and the on-going diagnostic work to understand and fix the problems

Porous niobium coatings fabricated with selective laser melting on titanium substrates: Preparation, characterization, and cell behavior

Energy Technology Data Exchange (ETDEWEB)

Zhang, Sheng [Science and Technology on Power Beam Processes Laboratory, Beijing Aeronautical Manufacturing Technology Research Institute (BAMTRI), Beijing 100024 (China); State Key Lab of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Cheng, Xian; Yao, Yao; Wei, Yehui [Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Han, Changjun; Shi, Yusheng [State Key Lab of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Wei, Qingsong, E-mail: wqs_xn@163.com [State Key Lab of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhang, Zhen, E-mail: zhangzhentitanium@163.com [State Key Lab of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China)

2015-08-01

Nb, an expensive and refractory element with good wear resistance and biocompatibility, is gaining more attention as a new metallic biomaterial. However, the high price of the raw material, as well as the high manufacturing costs because of Nb's strong oxygen affinity and high melting point have limited the widespread use of Nb and its compounds. To overcome these disadvantages, porous Nb coatings of various thicknesses were fabricated on Ti substrate via selective laser melting (SLM), which is a 3D printing technique that uses computer-controlled high-power laser to melt the metal. The morphology and microstructure of the porous Nb coatings, which had pores ranging from 15 to 50 μm in size, were characterized with scanning electron microscopy (SEM). The average hardness of the coating, which was measured with the linear intercept method, was 392 ± 37 HV. In vitro tests of the porous Nb coating which was monitored with SEM, immunofluorescence, and CCK-8 counts of cells, exhibited excellent cell morphology, attachment, and growth. The simulated body fluid test also proved the bioactivity of the Nb coating. Therefore, these new porous Nb coatings could potentially be used for enhanced early biological fixation to bone tissue. In addition, this study has shown that SLM technique could be used to fabricate coatings with individually tailored shapes and/or porosities from group IVB and VB biomedical metals and their alloys on stainless steel, Co–Cr, and other traditional biomedical materials without wasting raw materials. - Highlights: • Porous Nb coating was firstly fabricated on Ti substrate by SLM technique. • Morphology, microstructure and hardness of the coating were characterized. • In vitro test of the coating showed good cell attachment, morphology and growth.

Porous niobium coatings fabricated with selective laser melting on titanium substrates: Preparation, characterization, and cell behavior

International Nuclear Information System (INIS)

Zhang, Sheng; Cheng, Xian; Yao, Yao; Wei, Yehui; Han, Changjun; Shi, Yusheng; Wei, Qingsong; Zhang, Zhen

2015-01-01

Nb, an expensive and refractory element with good wear resistance and biocompatibility, is gaining more attention as a new metallic biomaterial. However, the high price of the raw material, as well as the high manufacturing costs because of Nb's strong oxygen affinity and high melting point have limited the widespread use of Nb and its compounds. To overcome these disadvantages, porous Nb coatings of various thicknesses were fabricated on Ti substrate via selective laser melting (SLM), which is a 3D printing technique that uses computer-controlled high-power laser to melt the metal. The morphology and microstructure of the porous Nb coatings, which had pores ranging from 15 to 50 μm in size, were characterized with scanning electron microscopy (SEM). The average hardness of the coating, which was measured with the linear intercept method, was 392 ± 37 HV. In vitro tests of the porous Nb coating which was monitored with SEM, immunofluorescence, and CCK-8 counts of cells, exhibited excellent cell morphology, attachment, and growth. The simulated body fluid test also proved the bioactivity of the Nb coating. Therefore, these new porous Nb coatings could potentially be used for enhanced early biological fixation to bone tissue. In addition, this study has shown that SLM technique could be used to fabricate coatings with individually tailored shapes and/or porosities from group IVB and VB biomedical metals and their alloys on stainless steel, Co–Cr, and other traditional biomedical materials without wasting raw materials. - Highlights: • Porous Nb coating was firstly fabricated on Ti substrate by SLM technique. • Morphology, microstructure and hardness of the coating were characterized. • In vitro test of the coating showed good cell attachment, morphology and growth

Perspective: Maintaining surface-phase purity is key to efficient open air fabricated cuprous oxide solar cells

Energy Technology Data Exchange (ETDEWEB)

Hoye, Robert L. Z., E-mail: rlzh2@cam.ac.uk, E-mail: jld35@cam.ac.uk; Ievskaya, Yulia; MacManus-Driscoll, Judith L., E-mail: rlzh2@cam.ac.uk, E-mail: jld35@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Brandt, Riley E.; Buonassisi, Tonio [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Heffernan, Shane [Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Musselman, Kevin P. [Department of Physics, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

2015-02-01

Electrochemically deposited Cu{sub 2}O solar cells are receiving growing attention owing to a recent doubling in efficiency. This was enabled by the controlled chemical environment used in depositing doped ZnO layers by atomic layer deposition, which is not well suited to large-scale industrial production. While open air fabrication with atmospheric pressure spatial atomic layer deposition overcomes this limitation, we find that this approach is limited by an inability to remove the detrimental CuO layer that forms on the Cu{sub 2}O surface. Herein, we propose strategies for achieving efficiencies in atmospherically processed cells that are equivalent to the high values achieved in vacuum processed cells.

Perspective: Maintaining surface-phase purity is key to efficient open air fabricated cuprous oxide solar cells

International Nuclear Information System (INIS)

Hoye, Robert L. Z.; Ievskaya, Yulia; MacManus-Driscoll, Judith L.; Brandt, Riley E.; Buonassisi, Tonio; Heffernan, Shane; Musselman, Kevin P.

2015-01-01

Electrochemically deposited Cu 2 O solar cells are receiving growing attention owing to a recent doubling in efficiency. This was enabled by the controlled chemical environment used in depositing doped ZnO layers by atomic layer deposition, which is not well suited to large-scale industrial production. While open air fabrication with atmospheric pressure spatial atomic layer deposition overcomes this limitation, we find that this approach is limited by an inability to remove the detrimental CuO layer that forms on the Cu 2 O surface. Herein, we propose strategies for achieving efficiencies in atmospherically processed cells that are equivalent to the high values achieved in vacuum processed cells

Fabrication, Tuning, Treatment and Testing of Two 3.5 Cell Photo-Injektor Cavities for the ELBE Linac

CERN Document Server

Arnold, A; Teichert, J; Xiang, R; Eremeev, G V; Kneisel, P; Stirbet, M; Turlington, L

2011-01-01

As part of a CRADA (Cooperative Research and Development Agreement) between Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and Thomas Jefferson Lab National Accelerator Facility (TJNAF) we have fabricated and tested two 1.3 GHz 3.5 cell photo-injector cavities from polycrystalline RRR niobium and large grain RRR niobium, respectively. The cavity with the better performance will replace the presently used injector cavity in the ELBE linac [1]. The cavities have been fabricated and pre-tuned at TJNAF, while the more sophisticated final field tuning; the adjustment of the external couplings and the field profile measurement of transverse electric modes for RF focusing [2] was done at HZDR. The following standard surface treatment and the vertical test were carried out at TJNAF’s production facilities. A major challenge turned out to be the rinsing of the cathode cell, which has small opening (Ø10 mm) to receive the cathode stalk. Another unexpected problem encountered after etching, since large visible defects a...

Roll-coating fabrication of flexible organic solar cells: comparison of fullerene and fullerene-free systems

DEFF Research Database (Denmark)

Liu, Kuan; Larsen-Olsen, Thue Trofod; Lin, Yuze

2016-01-01

Flexible organic solar cells (OSCs) based on a blend of low-bandgap polymer donor PTB7-TH and nonfullerene small molecule acceptor IEIC were fabricated via a roll-coating process under ambient atmosphere. Both an indium tin oxide (ITO)-free substrate and a flexible ITO substrate were employed...... in these inverted OSCs. OSCs with flexible ITO and ITO-free substrates exhibited power conversion efficiencies (PCEs) up to 2.26% and 1.79%, respectively, which were comparable to those of the reference devices based on fullerene acceptors under the same conditions. This is the first example for all roll......-coating fabrication procedures for flexible OSCs based on non-fullerene acceptors with the PCE exceeding 2%. The fullerene-free OSCs exhibited better dark storage stability than the fullerene-based control devices....

A new approach to characterize the effect of fabric deformation on thermal protective performance

International Nuclear Information System (INIS)

Li, Jun; Li, Xiaohui; Lu, Yehu; Wang, Yunyi

2012-01-01

It is very important to evaluate thermal protective performance (TPP) in laboratory-simulated fire scenes as accurately as possible. For this paper, to thoroughly understand the effect of fabric deformation on basic physical properties and TPP of flame-retardant fabrics exposed to flash fire, a new modified TPP testing apparatus was developed. Different extensions were employed to simulate the various extensions displayed during different body motions. The tests were also carried out with different air gaps. The results showed a significant decrease in air permeability after deformation. However, the change of thickness was slight. The fabric deformation had a complicated effect on thermal protection with different air gaps. The change of TPP depended on the balance between the surface contact area and the thermal insulation. The newly developed testing apparatus could be well employed to evaluate the effect of deformation on TPP of flame-resistant fabrics. (paper)

A new approach to characterize the effect of fabric deformation on thermal protective performance

Science.gov (United States)

Li, Jun; Li, Xiaohui; Lu, Yehu; Wang, Yunyi

2012-04-01

It is very important to evaluate thermal protective performance (TPP) in laboratory-simulated fire scenes as accurately as possible. For this paper, to thoroughly understand the effect of fabric deformation on basic physical properties and TPP of flame-retardant fabrics exposed to flash fire, a new modified TPP testing apparatus was developed. Different extensions were employed to simulate the various extensions displayed during different body motions. The tests were also carried out with different air gaps. The results showed a significant decrease in air permeability after deformation. However, the change of thickness was slight. The fabric deformation had a complicated effect on thermal protection with different air gaps. The change of TPP depended on the balance between the surface contact area and the thermal insulation. The newly developed testing apparatus could be well employed to evaluate the effect of deformation on TPP of flame-resistant fabrics.

Fabrication of keratin-silica hydrogel for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Kakkar, Prachi; Madhan, Balaraman, E-mail: bmadhan76@yahoo.co.in

2016-09-01

In the recent past, keratin has been fabricated into different forms of biomaterials like scaffold, gel, sponge, film etc. In lieu of the myriad advantages of the hydrogels for biomedical applications, a keratin-silica hydrogel was fabricated using tetraethyl orthosilicate (TEOS). Textural analysis shed light on the physical properties of the fabricated hydrogel, inturn enabling the optimization of the hydrogel. The optimized keratin-silica hydrogel was found to exhibit instant springiness, optimum hardness, with ease of spreadability. Moreover, the hydrogel showed excellent swelling with highly porous microarchitecture. MTT assay and DAPI staining revealed that keratin-silica hydrogel was biocompatible with fibroblast cells. Collectively, these properties make the fabricated keratin-silica hydrogel, a suitable dressing material for biomedical applications. - Highlights: • Keratin-silica hydrogel has been fabricated using sol–gel technique. • The hydrogel shows appropriate textural properties. • The hydrogel promotes fibroblast cells proliferation. • The hydrogel has potential soft tissue engineering applications like wound healing.

Fabrication of cathode supported tubular solid oxide electrolysis cell for high temperature steam electrolysis

Energy Technology Data Exchange (ETDEWEB)

Shao, Le; Wang, Shaorong; Qian, Jiqin; Xue, Yanjie; Liu, Renzhu

2011-01-15

In recent years, hydrogen has been identified as a potential alternative fuel and energy carrier for the future energy supply. Water electrolysis is one of the important hydrogen production technologies which do not emit carbon dioxide. High temperature steam electrolysis (HTSE) consumes even less electrical energy than low temperature water electrolysis. Theoretically, HTSE using solid oxide electrolysis cells (SOEC) can efficiently utilize renewable energy to produce hydrogen, and it is also possible to operate the SOEC in reverse mode as the solid oxide fuel cell (SOFC) to produce electricity. Tubular SOFC have been widely investigated. In this study, tubular solid oxide cells were fabricated by dip-coating and cosintering techniques. In SOEC mode, results suggested that steam ratio had a strong impact on the performance of the tubular cell; the tubular SOEC preferred to be operated at high steam ratio in order to avoid concentration polarization. The microstructure of the tubular SOEC should therefore be optimized for high temperature steam electrolysis.

Fabrication of bioinspired composite nanofiber membranes with robust superhydrophobicity for direct contact membrane distillation.

Science.gov (United States)

Liao, Yuan; Wang, Rong; Fane, Anthony G

2014-06-03

The practical application of membrane distillation (MD) for water purification is hindered by the absence of desirable membranes that can fulfill the special requirements of the MD process. Compared to the membranes fabricated by other methods, nanofiber membranes produced by electrospinning are of great interest due to their high porosity, low tortuosity, large surface pore size, and high surface hydrophobicity. However, the stable performance of the nanofiber membranes in the MD process is still unsatisfactory. Inspired by the unique structure of the lotus leaf, this study aimed to develop a strategy to construct superhydrophobic composite nanofiber membranes with robust superhydrophobicity and high porosity suitable for use in MD. The newly developed membrane consists of a superhydrophobic silica-PVDF composite selective skin formed on a polyvinylidene fluoride (PVDF) porous nanofiber scaffold via electrospinning. This fabrication method could be easily scaled up due to its simple preparation procedures. The effects of silica diameter and concentration on membrane contact angle, sliding angle, and MD performance were investigated thoroughly. For the first time, the direct contact membrane distillation (DCMD) tests demonstrate that the newly developed membranes are able to present stable high performance over 50 h of testing time, and the superhydrophobic selective layer exhibits excellent durability in ultrasonic treatment and a continuous DCMD test. It is believed that this novel design strategy has great potential for MD membrane fabrication.

Fabrication and characterization of a cathode-supported tubular solid oxide fuel cell

Energy Technology Data Exchange (ETDEWEB)

Zhao, Chunhua; Liu, Renzhu; Wang, Shaorong; Wang, Zhenrong; Qian, Jiqin; Wen, Tinglian [CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050 (China)

2009-07-15

A cathode-supported tubular solid oxide fuel cell (CTSOFC) with the length of 6.0 cm and outside diameter of 1.0 cm has been successfully fabricated via dip-coating and co-sintering techniques. A crack-free electrolyte film with a thickness of {proportional_to}14 {mu}m was obtained by co-firing of cathode/cathode active layer/electrolyte/anode at 1250 C. The relative low densifying temperature for electrolyte was attributed to the large shrinkage of the green tubular which assisted the densification of electrolyte. The assembled cell was electrochemically characterized with humidified H{sub 2} as fuel and O{sub 2} as oxidant. The open circuit voltages (OCV) were 1.1, 1.08 and 1.06 V at 750, 800 and 850 C, respectively, with the maximum power densities of 157, 272 and 358 mW cm{sup -2} at corresponding temperatures. (author)

Clinical and immunological status of a newly diagnosed HIV positive ...

African Journals Online (AJOL)

Objective: To evaluate the clinical and the immune status of newly HIV diagnosed patients, in Marrakech city and its neighboring area, in Morocco. Methods: We performed a retrospective study on 235 patients who have been previously confirmed for HIV infection, and underwent a CD4 T cells using flow cytometry ...

Fabrication of electrolytic cell for online post-column electrochemical derivatization in ion chromatography

Energy Technology Data Exchange (ETDEWEB)

Wu Shuchao [Department of Chemistry, Xixi Campus, Zhejiang University, Hangzhou 310028, Zhejiang (China); Xu Wei [State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310028, Zhejiang (China); Yang Bingcheng [School of Pharmacy, East China University of Science and Technology, Shanghai 200237 (China); Ye Mingli [Thermofisher scientific (China), Shanghai 201203 (China); Zhang Peimin [Department of Chemistry, Xixi Campus, Zhejiang University, Hangzhou 310028, Zhejiang (China); Shentu Chao [College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310015 (China); Zhu Yan, E-mail: zhuyan@zju.edu.cn [Department of Chemistry, Xixi Campus, Zhejiang University, Hangzhou 310028, Zhejiang (China)

2012-07-20

Highlight: Black-Right-Pointing-Pointer An electrolytic cell including ruthenium modified titanium electrode was fabricated. Black-Right-Pointing-Pointer Ion chromatography/electrochemical derivatization/fluorescence detection was developed. Black-Right-Pointing-Pointer Strong oxidation capacity of this EC was obtained by using the Ru/Ti electrode with large surface area. - Abstract: An electrolytic cell (EC), composed of two ruthenium-plated titanium electrodes separated by cation-exchange membranes, was fabricated and evaluated for online postcolumn derivatization in ion chromatography (IC). Folic acid (FA) and methotrexate (MTX) were preliminarily used as prototype analytes to test the performance of EC. After separation by an anion exchange column, FA and MTX, which emit very weak fluorescence when excited, were electrochemically oxidized online in the anode chamber of the EC. The compounds with strong fluorescence, which are oxidation products, were detected by the fluorescence detector. The phosphate buffer solution (100 mM KH{sub 2}PO{sub 4}) served as an optimal eluent for anion exchange chromatographic separation and a suitable supporting electrolyte for electro-oxidation, leading to ideal compatibility between IC separation and the postcolumn electrochemical derivatization. For the presently proposed method, the linear ranges were from 0.01 mg L{sup -1} to 5 mg L{sup -1} for both FA and MTX. The detection limits of FA and MTX were 1.8 and 2.1 {mu}g L{sup -1}, and the relative standard deviations (RSD, n = 7) were 2.9% and 3.6%, respectively. The method was applied for the simultaneous determination of FA and MTX in the plasma of patients being treated for rheumatoid arthritis. The determination of MTX in the urine of the patients of diffuse large B cell lymphoma was also demonstrated.

Fabrication of AgInSe2 heterojunction solar cell

Science.gov (United States)

Khudayer, Iman Hameed

2018-05-01

Silver, Indium Selenium thin film with a thickness (5001±30) nm, deposited by thermal evaporation methods at RT and annealing3temperature (Ta = 400, 500 and 600) K on a substrate of glass to study structural and optical properties of thin films and on p-Si wafer to fabricate the AgInSe2/p-Si heterojunction solar cell. XRD analysis shows that the AgInSe2 (AIS) deposited film at RT and annealing3temperature (Ta = 400, 500 and 600) K have polycrystalline structure. The average grain size has been estimated from AFM images. The energy gap was estimated from the optical transmittance using a spectrometer type (UV.-Visible 1800 spectra photometer). From I-V characterization, the photovoltaic parameters such as, open-circuit voltage, short-circuit current density, fill factor, ideality factor, and efficiencies, were computed. As well as the built-in potential, carrier concentration and depletion width were determined under RT and (Ta = 400, 500 and 600) K from C-V measurement.

Identification of GAD65 AA 114-122 reactive 'memory-like' NK cells in newly diagnosed Type 1 diabetic patients by HLA-class I pentamers.

Science.gov (United States)

Perri, Valentina; Gianchecchi, Elena; Cifaldi, Loredana; Pellegrino, Marsha; Giorda, Ezio; Andreani, Marco; Cappa, Marco; Fierabracci, Alessandra

2017-01-01

Type 1 diabetes is an autoimmune disease, in which pancreatic β cells are destroyed by autoreactive T cells in genetically predisposed individuals. Serum beta cell autoantibody specificities have represented the mainstay for classifying diabetes as autoimmune-mediated and for stratifying risk in first-degree relatives. In recent years, approaches were attempted to solve the difficult issue of detecting rare antigen-specific autoreactive T cells and their significance to etiopathogenesis such as the use of the MHC multimer technology. This tool allowed the specific detection of increased percentages of GAD65 autoreactive T cells by means of HLA A*02:01 GAD65 AA 114-122 pentamers in newly diagnosed diabetics. Here we provide evidence that GAD65 AA 114-122 pentamers can depict a GAD65 AA114-122 peptide expandable population of functionally and phenotypically skewed, preliminary characterized CD3-CD8dullCD56+ 'memory-like' NK cells in PBMC of newly diagnosed diabetics. Our data suggest that the NK cell subset could bind the HLA class I GAD65 AA 114-122 pentamer through ILT2 inhibitory receptor. CD107a expression revealed increased degranulation of CD3-CD8dullCD56+ NK cells in GAD65 AA 114-122 and FLU peptide expanded peripheral blood mononuclear cells of diabetics following GAD65 AA 114-122 peptide HLA A*02:01 presentation in respect to the unpulsed condition. CD107a expression was enriched in ILT2 positive NK cells. As opposite to basal conditions where similar percentages of CD3-CD56+ILT2+ cells were detected in diabetics and controls, CD3-CD56+CD107a+ and CD3-CD56+ILT2+CD107a+ cells were significantly increased in T1D PBMC either GAD65 AA 114-122 or FLU peptides stimulated after co-culture with GAD65 AA 114-122 pulsed APCs. As control, healthy donor NK cells showed similar degranulation against both GAD65 AA 114-122 pulsed and unpulsed APCs. The pathogenetic significance of the CD3-CD8dullCD56+ 'memory-like NK cell subset' with increased response upon secondary

Light-trapping in solar cells by photonic nanostructures. The need for benchmarking and fabrication assessments

Energy Technology Data Exchange (ETDEWEB)

Lenzmann, F.O.; Salpakari, J.; Weeber, A.W.; Olson, C.L. [ECN Solar Energy, Petten (Netherlands)

2013-07-15

Light-trapping in solar cells by photonic nanostructures, e.g., nano-textured surfaces or metallic and nonmetallic nanoparticles is a research area of great promise. A large multitude of configurations is being explored and there is a rising need for (a set of) assessment elements that help to narrow in on the most viable ones. This paper discusses two examples: benchmark devices and the assessment of fabrication aspects for the nanostructures.

Precise Morphology Control and Continuous Fabrication of Perovskite Solar Cells Using Droplet-Controllable Electrospray Coating System.

Science.gov (United States)

Hong, Seung Chan; Lee, Gunhee; Ha, Kyungyeon; Yoon, Jungjin; Ahn, Namyoung; Cho, Woohyung; Park, Mincheol; Choi, Mansoo

2017-03-08

Herein, we developed a novel electrospray coating system for continuous fabrication of perovskite solar cells with high performance. Our system can systemically control the size of CH 3 NH 3 PbI 3 precursor droplets by modulating the applied electrical potential, shown to be a crucial factor for the formation of perovskite films. As a result, we have obtained pinhole-free and large grain-sized perovskite solar cells, yielding the best PCE of 13.27% with little photocurrent hysteresis. Furthermore, the average PCE through the continuous coating process was 11.56 ± 0.52%. Our system demonstrates not only the high reproducibility but also a new way to commercialize high-quality perovskite solar cells.

Cadmium tolerant characteristic of a newly isolated Lactococcus lactis subsp. lactis.

Science.gov (United States)

Sheng, Yao; Wang, Ying; Yang, Xuan; Zhang, Boyang; He, Xiaoyun; Xu, Wentao; Huang, Kunlun

2016-12-01

Environmental contamination caused by heavy metals poses a major threat to the wildlife and human health for their toxicity and intrinsically persistent nature. Some specific food grade bacteria have properties that enable them to eliminate heavy metals from food and water. Lactococcus lactis subsp. lactis, newly isolated from pickles, is a cadmium (Cd) tolerant bacteria. Cd resistant properties of the lactis was evaluated under different Cd stresses. Cd accumulation in different cellular parts was determined by ICP-MS and cell morphology changes were measured by SEM-EDS and TEM-EDS. In addition, functional groups associated with Cd resistance were detected by infrared spectroscopic analysis. The results indicated that Cd mainly accumulated in the cell surface structures including cytoderm and cytomembrane. Functional groups such as OH and NH 2 in the cell surface played essential roles in Cd biosorption. The elements of O, P, S, and N of polysaccharide, membrane protein and phosphatidate in the cell surface structures might be responsible for Cd biosorption for their strong electronegativity. This study indicated that ultrastructural analysis can be a supplemental method to study heavy metal resistance mechanism of microorganism and the newly isolated lactococcus lactis subsp. lactis has great potential to be applied to decontamination of heavy metals. Copyright © 2016 Elsevier B.V. All rights reserved.

Fabrication of high aspect ratio nanocell lattices by ion beam irradiation

International Nuclear Information System (INIS)

Ishikawa, Osamu; Nitta, Noriko; Taniwaki, Masafumi

2016-01-01

Highlights: • Nanocell lattice with a high aspect ratio on InSb semiconductor surface was fabricated by ion beam irradiation. • The fabrication technique consisting of top-down and bottom-up processes was performed in FIB. • High aspect ratio of 2 was achieved in nanocell lattice with a 100 nm interval. • The intermediate-flux irradiation is favorable for fabrication of nanocell with a high aspect ratio. - Abstract: A high aspect ratio nanocell lattice was fabricated on the InSb semiconductor surface using the migration of point defects induced by ion beam irradiation. The fabrication technique consisting of the top-down (formation of voids and holes) and bottom-up (growth of voids and holes into nanocells) processes was performed using a focused ion beam (FIB) system. A cell aspect ratio of 2 (cell height/cell diameter) was achieved for the nanocell lattice with a 100 nm dot interval The intermediate-flux ion irradiation during the bottom-up process was found to be optimal for the fabrication of a high aspect ratio nanocell.

Newly-derived neuroblastoma cell lines propagated in serum-free media recapitulate the genotype and phenotype of primary neuroblastoma tumours.

Science.gov (United States)

Bate-Eya, Laurel T; Ebus, Marli E; Koster, Jan; den Hartog, Ilona J M; Zwijnenburg, Danny A; Schild, Linda; van der Ploeg, Ida; Dolman, M Emmy M; Caron, Huib N; Versteeg, Rogier; Molenaar, Jan J

2014-02-01

Recently protocols have been devised for the culturing of cell lines from fresh tumours under serum-free conditions in defined neural stem cell medium. These cells, frequently called tumour initiating cells (TICs) closely retained characteristics of the tumours of origin. We report the isolation of eight newly-derived neuroblastoma TICs from six primary neuroblastoma tumours and two bone marrow metastases. The primary tumours from which these TICs were generated have previously been fully typed by whole genome sequencing (WGS). Array comparative genomic hybridisation (aCGH) analysis showed that TIC lines retained essential characteristics of the primary tumours and exhibited typical neuroblastoma chromosomal aberrations such as MYCN amplification, gain of chromosome 17q and deletion of 1p36. Protein analysis showed expression for neuroblastoma markers MYCN, NCAM, CHGA, DBH and TH while haematopoietic markers CD19 and CD11b were absent. We analysed the growth characteristics and confirmed tumour-forming potential using sphere-forming assays, subcutaneous and orthotopic injection of these cells into immune-compromised mice. Affymetrix mRNA expression profiling of TIC line xenografts showed an expression pattern more closely mimicking primary tumours compared to xenografts from classical cell lines. This establishes that these neuroblastoma TICs cultured under serum-free conditions are relevant and useful neuroblastoma tumour models. Copyright © 2013 Elsevier Ltd. All rights reserved.

Aging studies on micro-fabricated alkali buffer-gas cells for miniature atomic clocks

International Nuclear Information System (INIS)

Abdullah, S.; Affolderbach, C.; Gruet, F.; Mileti, G.

2015-01-01

We report an aging study on micro-fabricated alkali vapor cells using neon as a buffer gas. An experimental atomic clock setup is used to measure the cell's intrinsic frequency, by recording the clock frequency shift at different light intensities and extrapolating to zero intensity. We find a drift of the cell's intrinsic frequency of (−5.2 ± 0.6) × 10 −11 /day and quantify deterministic variations in sources of clock frequency shifts due to the major physical effects to identify the most probable cause of the drift. The measured drift is one order of magnitude stronger than the total frequency variations expected from clock parameter variations and corresponds to a slow reduction of buffer gas pressure inside the cell, which is compatible with the hypothesis of loss of Ne gas from the cell due to its permeation through the cell windows. A negative drift on the intrinsic cell frequency is reproducible for another cell of the same type. Based on the Ne permeation model and the measured cell frequency drift, we determine the permeation constant of Ne through borosilicate glass as (5.7 ± 0.7) × 10 −22 m 2 s −1  Pa −1 at 81 °C. We propose this method based on frequency metrology in an alkali vapor cell atomic clock setup based on coherent population trapping for measuring permeation constants of inert gases

The influence of cell morphology on the compressive fatigue behavior of Ti-6Al-4V meshes fabricated by electron beam melting.

Science.gov (United States)

Zhao, S; Li, S J; Hou, W T; Hao, Y L; Yang, R; Misra, R D K

2016-06-01

Additive manufacturing technique is a promising approach for fabricating cellular bone substitutes such as trabecular and cortical bones because of the ability to adjust process parameters to fabricate different shapes and inner structures. Considering the long term safe application in human body, the metallic cellular implants are expected to exhibit superior fatigue property. The objective of the study was to study the influence of cell shape on the compressive fatigue behavior of Ti-6Al-4V mesh arrays fabricated by electron beam melting. The results indicated that the underlying fatigue mechanism for the three kinds of meshes (cubic, G7 and rhombic dodecahedron) is the interaction of cyclic ratcheting and fatigue crack growth on the struts, which is closely related to cumulative effect of buckling and bending deformation of the strut. By increasing the buckling deformation on the struts through cell shape design, the cyclic ratcheting rate of the meshes during cyclic deformation was decreased and accordingly, the compressive fatigue strength was increased. With increasing bending deformation of struts, fatigue crack growth in struts contributed more to the fatigue damage of meshes. Rough surface and pores contained in the struts significantly deteriorated the compressive fatigue strength of the struts. By optimizing the buckling and bending deformation through cell shape design, Ti-6Al-4V alloy cellular solids with high fatigue strength and low modulus can be fabricated by the EBM technique. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hydrothermally Activated Graphene Fiber Fabrics for Textile Electrodes of Supercapacitors.

Science.gov (United States)

Li, Zheng; Huang, Tieqi; Gao, Weiwei; Xu, Zhen; Chang, Dan; Zhang, Chunxiao; Gao, Chao

2017-11-28

Carbon textiles are promising electrode materials for wearable energy storage devices owing to their conductive, flexible, and lightweight features. However, there still lacks a perfect choice for high-performance carbon textile electrodes with sufficient electrochemical activity. Graphene fiber fabrics (GFFs) are newly discovered carbon textiles, exhibiting various attractive properties, especially a large variability on the microstructure. Here we report the fabrication of hierarchical GFFs with significantly enlarged specific surface area using a hydrothermal activation strategy. By carefully optimize the activation process, the hydrothermally activated graphene fiber fabrics (HAGFFs) could achieve an areal capacitance of 1060 mF cm -2 in a very thin thickness (150 μm) and the capacitance is easily magnified by overlaying several layers of HAGFFs, even up to a record value of 7398 mF cm -2 . Meanwhile, a good rate capability and a long cycle life are also attained. As compared with other carbon textiles, including the commercial carbon fiber cloths, our HAGFFs present much better capacitive performance. Therefore, the mechanically stable, flexible, conductive, and highly active HAGFFs have provided an option for high-performance textile electrodes.

Colloidal Sb2S3 Nanocrystals: Synthesis, Characterization and Fabrication of Solid-State Semiconductor Sensitized Solar Cell

KAUST Repository

Abulikemu, Mutalifu

2015-12-26

Inorganic nanocrystals composed of earth-abundant and non-toxic elements are crucial to fabricated sustainable photovoltaic devices in large scale. In this study, various-shaped and different phases of antimony sulfide nanocrystals, which is composed of non-scarce and non-toxic elements, are synthesized using hot-injection colloidal method. The effect of various synthetic parameters on the final morphology is explored. Also, foreign ion (Chlorine) effects on the morphology of Sb2S3 nanocrystals have been observed. Structural, optical and morphological properties of the nanocrystals were investigated, and Sb2S3 nanocrystal-based solid-state semiconductor-sensitized solar cells were fabricated using as-prepared nanocrystals. We achieved promising power conversion efficiencies of 1.48%.

Colloidal Sb2S3 Nanocrystals: Synthesis, Characterization and Fabrication of Solid-State Semiconductor Sensitized Solar Cell

KAUST Repository

Abulikemu, Mutalifu; Del Gobbo, Silvano; Anjum, Dalaver H.; Malik, Mohammad A; Bakr, Osman

2015-01-01

Inorganic nanocrystals composed of earth-abundant and non-toxic elements are crucial to fabricated sustainable photovoltaic devices in large scale. In this study, various-shaped and different phases of antimony sulfide nanocrystals, which is composed of non-scarce and non-toxic elements, are synthesized using hot-injection colloidal method. The effect of various synthetic parameters on the final morphology is explored. Also, foreign ion (Chlorine) effects on the morphology of Sb2S3 nanocrystals have been observed. Structural, optical and morphological properties of the nanocrystals were investigated, and Sb2S3 nanocrystal-based solid-state semiconductor-sensitized solar cells were fabricated using as-prepared nanocrystals. We achieved promising power conversion efficiencies of 1.48%.

Fabrication of large size alginate beads for three-dimensional cell-cluster culture

Science.gov (United States)

Zhang, Zhengtao; Ruan, Meilin; Liu, Hongni; Cao, Yiping; He, Rongxiang

2017-08-01

We fabricated large size alginate beads using a simple microfluidic device under a co-axial injection regime. This device was made by PDMS casting with a mold formed by small diameter metal and polytetrafluorothylene tubes. Droplets of 2% sodium alginate were generated in soybean oil through the device and then cross-linked in a 2% CaCl2 solution, which was mixed tween80 with at a concentration of 0.4 to 40% (w/v). Our results showed that the morphology of the produced alginate beads strongly depends on the tween80 concentration. With the increase of concentration of tween80, the shape of the alginate beads varied from semi-spherical to tailed-spherical, due to the decrease of interface tension between oil and cross-link solution. To access the biocompatibility of the approach, MCF-7 cells were cultured with the alginate beads, showing the formation of cancer cells clusters which might be useful for future studies.

Study on the effect of hypoxia on apoptosis of cultured newly born rat cardiac myocytes

International Nuclear Information System (INIS)

Su Weidong; Li Huiqiang; Yao Zhi

2005-01-01

Objective: To investigate the possible hypoxia-mediated cellular apoptosis after ischemic cardiac injury via a model of cultured newly born rat cardiac myocytes. Methods: Cardiac myocytes cultures from newly born rats (1-3d) were examined for apoptosis with HE stain and flow cytometry after cultured 96h and again examined after exposure to hypoxic environment for 16h. Results: Apoptotic changes were evident in the hypoxic culture cells. The HE stain revealed cellular shrinkage, nuclear chromosomal condensation with cytoplasmic eosinophilia. Also, distinct apoptosis peak was observed in the flow cytometry. Conclusion: This experiment proved that hypoxic model of cardiac myocyte culture showed definite apoptosis of the cells. (authors)

New Fabrication Strategies for Polymer Electrolyte Batteries

National Research Council Canada - National Science Library

Shriver, D

1997-01-01

.... The objective of this research was to fabricate lithium-polymer batteries by techniques that may produce a thin electrolyte and cathode films and with minimal contamination during fabrication. One such technique, ultrasonic spray was used. Another objective of this research was to test lithium cells that incorporate the new polymer electrolytes and polyelectrolytes.

MAPLE fabricated magnetite@eugenol and (3-hidroxybutyric acid-co-3-hidroxyvaleric acid)–polyvinyl alcohol microspheres coated surfaces with anti-microbial properties

Energy Technology Data Exchange (ETDEWEB)

Grumezescu, Valentina [Lasers Department, National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG-36, Magurele, Bucharest (Romania); Department of Science and Engineering of Oxidic Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 1–7 Polizu Street, 011061 Bucharest (Romania); Holban, Alina Maria [Microbiology Immunology Department, Faculty of Biology, University of Bucharest, 1–3 Portocalelor Lane, Sector 5, 77206Bucharest (Romania); Iordache, Florin [Institute of Cellular Biology and Pathology of Romanian Academy, “Nicolae Simionescu”, Department of Fetal and Adult Stem Cell Therapy, 8, B.P. Hasdeu, Bucharest 050568 (Romania); Socol, Gabriel [Lasers Department, National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG-36, Magurele, Bucharest (Romania); Mogoşanu, George Dan [Department of Pharmacognosy and Phytotherapy, Faculty of Pharmacy, University of Medicine and Pharmacy of Craiova, 2 PetruRareş Street, 200349 Craiova (Romania); Grumezescu, Alexandru Mihai, E-mail: grumezescu@yahoo.com [Department of Science and Engineering of Oxidic Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 1–7 Polizu Street, 011061 Bucharest (Romania); Ficai, Anton; Vasile, Bogdan Ştefan [Department of Science and Engineering of Oxidic Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 1–7 Polizu Street, 011061 Bucharest (Romania); Truşcă, Roxana [S.C. Metav-CD S.A., 31Rosetti Str., 020015 Bucharest (Romania); Chifiriuc, Mariana Carmen [Microbiology Immunology Department, Faculty of Biology, University of Bucharest, 1–3 Portocalelor Lane, Sector 5, 77206Bucharest (Romania); others, and

2014-07-01

This study reports the biological applications of a newly fabricated water dispersible nanostructure, based on magnetite (Fe{sub 3}O{sub 4}) and eugenol (E), prepared in a well-shaped spherical form by precipitation method. The presence of Fe{sub 3}O{sub 4}@E nanoparticles has been confirmed by transmission electron microscopy (TEM). Nanoparticles have been embedded into poly(3-hidroxybutyric acid-co-3-hidroxyvaleric acid)–polyvinyl alcohol (P(3HB-3HV)–PVA) microspheres by oil-in-water emulsion technique. Functionalized P(3HB-3HV)–PVA–Fe{sub 3}O{sub 4}@E microspheres coatings have been fabricated by matrix assisted pulsed laser evaporation (MAPLE). The coatings have been characterized by infrared microscopy (IRM) and scanning electron microscopy (SEM). In vitro biofilm formation by Staphylococcus aureus and Pseudomonas aeruginosa was assessed by the viable cell counts technique. Nanomaterial biocompatibility has been investigated by analyzing the phenotypic changes of cultured eukaryotic cells. Besides their excellent anti-adherence and anti-biofilm properties, the MAPLE coatings have the advantages of using bioactive natural compounds, which are less toxic and easily biodegradable than current antibiotics. This approach could be used as a successful alternative or adjuvant method to control and prevent microbial biofilms associated infections.

MAPLE fabricated magnetite@eugenol and (3-hidroxybutyric acid-co-3-hidroxyvaleric acid)–polyvinyl alcohol microspheres coated surfaces with anti-microbial properties

International Nuclear Information System (INIS)

Grumezescu, Valentina; Holban, Alina Maria; Iordache, Florin; Socol, Gabriel; Mogoşanu, George Dan; Grumezescu, Alexandru Mihai; Ficai, Anton; Vasile, Bogdan Ştefan; Truşcă, Roxana; Chifiriuc, Mariana Carmen

2014-01-01

This study reports the biological applications of a newly fabricated water dispersible nanostructure, based on magnetite (Fe 3 O 4 ) and eugenol (E), prepared in a well-shaped spherical form by precipitation method. The presence of Fe 3 O 4 @E nanoparticles has been confirmed by transmission electron microscopy (TEM). Nanoparticles have been embedded into poly(3-hidroxybutyric acid-co-3-hidroxyvaleric acid)–polyvinyl alcohol (P(3HB-3HV)–PVA) microspheres by oil-in-water emulsion technique. Functionalized P(3HB-3HV)–PVA–Fe 3 O 4 @E microspheres coatings have been fabricated by matrix assisted pulsed laser evaporation (MAPLE). The coatings have been characterized by infrared microscopy (IRM) and scanning electron microscopy (SEM). In vitro biofilm formation by Staphylococcus aureus and Pseudomonas aeruginosa was assessed by the viable cell counts technique. Nanomaterial biocompatibility has been investigated by analyzing the phenotypic changes of cultured eukaryotic cells. Besides their excellent anti-adherence and anti-biofilm properties, the MAPLE coatings have the advantages of using bioactive natural compounds, which are less toxic and easily biodegradable than current antibiotics. This approach could be used as a successful alternative or adjuvant method to control and prevent microbial biofilms associated infections.

Laser-assisted fabrication of batteries on wax paper

International Nuclear Information System (INIS)

Chitnis, G; Ziaie, B; Tan, T

2013-01-01

The functionality of paper-based diagnostic devices can be significantly enhanced by their integration with an on-board energy source. Here, we demonstrate the fabrication of paper-based electrochemical cells on wax paper using CO 2 laser surface treatment and micromachining. A four cell zinc–copper battery shows a steady open-circuit voltage of ∼3 V and can provide 0.25 mA for at least 30 min when connected to a 10 kΩ load. Higher voltages and current values can be obtained by adjusting the number and size of electrochemical cells in the battery without changing the fabrication process. (paper)

Fabrication and Characterization of a Perovskite-Type Solar Cell with a Substrate Size of 70 mm

Directory of Open Access Journals (Sweden)

Takeo Oku

2015-10-01

Full Text Available A perovskite-type solar cell with a substrate size of 70 mm × 70 mm was fabricated by a simple spin-coating method using a mixed solution. The photovoltaic properties of the TiO2/CH3NH3PbI3-based photovoltaic devices were investigated by current density-voltage characteristic and incident photon to current conversion efficiency measurements. Their short-circuit current densities were almost constant over a large area. The photoconversion efficiency was influenced by the open-circuit voltage, which depended on the distance from the center of the cell.

Fabrication and Characterization of New Composite Tio2 Carbon Nanofiber Anodic Catalyst Support for Direct Methanol Fuel Cell via Electrospinning Method

Science.gov (United States)

Abdullah, N.; Kamarudin, S. K.; Shyuan, L. K.; Karim, N. A.

2017-12-01

Platinum (Pt) is the common catalyst used in a direct methanol fuel cell (DMFC). However, Pt can lead towards catalyst poisoning by carbonaceous species, thus reduces the performance of DMFC. Thus, this study focuses on the fabrication of a new composite TiO2 carbon nanofiber anodic catalyst support for direct methanol fuel cells (DMFCs) via electrospinning technique. The distance between the tip and the collector (DTC) and the flow rate were examined as influencing parameters in the electrospinning technique. To ensure that the best catalytic material is fabricated, the nanofiber underwent several characterizations and electrochemical tests, including FTIR, XRD, FESEM, TEM, and cyclic voltammetry. The results show that D18, fabricated with a flow rate of 0.1 mLhr-1 and DTC of 18 cm, is an ultrafine nanofiber with the smallest average diameter, 136.73 ± 39.56 nm. It presented the highest catalyst activity and electrochemical active surface area value as 274.72 mAmg-1 and 226.75m2 g-1 PtRu, respectively, compared with the other samples.

Fabrication and characterization of perovskite-type solar cells with Nb-doped TiO{sub 2} layers

Energy Technology Data Exchange (ETDEWEB)

Saito, Jo; Oku, Takeo, E-mail: oku@mat.usp.ac.jp; Suzuki, Atsushi; Akiyama, Tsuyoshi [The University of Shiga Prefecture, Hikone, Shiga 522-8533 (Japan)

2016-02-01

Organic-inorganic hybrid heterojunction solar cells containing perovskite CH{sub 3}NH{sub 3}PbI{sub 3} using Nb-doped TiO{sub 2} as an electron-transporting layer were fabricated and characterized. Nb-doped TiO{sub 2} layer showed an improvement of the short-circuit current density and power conversion efficiency using Ti{sub 0.95}Nb{sub 0.05}O{sub 2}.

Fabrication of large area woodpile structure in polymer

Science.gov (United States)

Gupta, Jaya Prakash; Dutta, Neilanjan; Yao, Peng; Sharkawy, Ahmed S.; Prather, Dennis W.

2009-02-01

A fabrication process of three-dimensional Woodpile photonic crystals based on multilayer photolithography from commercially available photo resist SU8 have been demonstrated. A 6-layer, 2 mm × 2mm woodpile has been fabricated. Different factors that influence the spin thickness on multiple resist application have been studied. The fabrication method used removes, the problem of intermixing, and is more repeatable and robust than the multilayer fabrication techniques for three dimensional photonic crystal structures that have been previously reported. Each layer is developed before next layer photo resist spin, instead of developing the whole structure in the final step as used in multilayer process. The desired thickness for each layer is achieved by the calibration of spin speed and use of different photo resist compositions. Deep UV exposure confinement has been the defining parameter in this process. Layer uniformity for every layer is independent of the previous developed layers and depends on the photo resist planarizing capability, spin parameters and baking conditions. The intermixing problem, which results from the previous layers left uncrossed linked photo resist, is completely removed in this process as the previous layers are fully developed, avoiding any intermixing between the newly spun and previous layers. Also this process gives the freedom to redo every spin any number of times without affecting the previously made structure, which is not possible in other multilayer process where intermediate developing is not performed.

Investigation on cell biocompatible behaviors of polyaniline film fabricated via electroless surface polymerization

International Nuclear Information System (INIS)

Liu Sheng; Wang Jinqing; Zhang Dong; Zhang Puliang; Ou Junfei; Liu Bin; Yang Shengrong

2010-01-01

Considering for the potential application in tissue engineering, polyaniline (PANi) film was fabricated via a two-step route: a self-assembled monolayer of C 6 H 5 NHC 3 H 6 Si(OMe) 3 was firstly formed on the single-crystal Si substrate; the conducting PANi film was then prepared through electroless surface polymerization of the aniline molecules on the aniline monolayer-bearing silane surface in an acidic aqueous solution. The formation of PANi film on Si surface was confirmed by characterizations of X-ray photoelectron spectroscope (XPS) and specular reflectance Fourier transform infrared (SR-FTIR) spectrum, etc. At last, the proliferation behaviors of PC-12 cells on the PANi film surface were studied by the [3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) colorimetric assays, acridine orange fluorometric staining, and scanning electron microscope (SEM) observation, etc. The results demonstrate that the as-prepared PANi film provides high ability for cell proliferation, exhibiting promising potentials as surface coating to cultivate neuronal cells for applications in the tissue engineering.

Rapid fabrication of microfluidic polymer electrolyte membrane fuel cell in PDMS by surface patterning of perfluorinated ion-exchange resin

Energy Technology Data Exchange (ETDEWEB)

Song, Yong-Ak; Han, Jongyoon [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States); Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States); Batista, Candy [Roxbury Community College, 1234 Columbus Ave., Roxbury Crossing, MA 02120 (United States); Sarpeshkar, Rahul [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States)

2008-09-01

In this paper we demonstrate a simple and rapid fabrication method for a microfluidic polymer electrolyte membrane (PEM) fuel cell using polydimethylsiloxane (PDMS), which has become the de facto standard material in BioMEMS. Instead of integrating a Nafion sheet film between two layers of a PDMS device in a traditional ''sandwich format,'' we pattern a perfluorinated ion-exchange resin such as a Nafion resin on a glass substrate using a reversibly bonded PDMS microchannel to generate an ion-selective membrane between the fuel-cell electrodes. After this patterning step, the assembly of the microfluidic fuel cell is accomplished by simple oxygen plasma bonding between the PDMS chip and the glass substrate. In an example implementation, the planar PEM microfluidic fuel cell generates an open circuit voltage of 600-800 mV and delivers a maximum current output of nearly 4 {mu}A. To enhance the power output of the fuel cell we utilize self-assembled colloidal arrays as a support matrix for the Nafion resin. Such arrays allow us to increase the thickness of the ion-selective membrane to 20 {mu}m and increase the current output by 166%. Our novel fabrication method enables rapid prototyping of microfluidic fuel cells to study various ion-exchange resins for the polymer electrolyte membrane. Our work will facilitate the development of miniature, implantable, on-chip power sources for biomedical applications. (author)

Fabrication and Optoelectrical Properties of IZO/Cu2O Heterostructure Solar Cells by Thermal Oxidation

Directory of Open Access Journals (Sweden)

Cheng-Chiang Chen

2012-01-01

Full Text Available Indium zinc oxide (IZO/cupper oxide (Cu2O is a nontoxic nature and an attractive all-oxide candidate for low-cost photovoltaic (PV applications. The present paper reports on the fabrication of IZO/Cu2O heterostructure solar cells which the Cu2O layers were prepared by oxidation of Cu thin films deposited on glass substrate. The measured parameters of cells were the short-circuit current (Isc, the open-circuit voltage (Voc, the maximum output power (Pm, the fill factor (FF, and the efficiency (η, which had values of 0.11 mA, 0.136 V, 5.05 μW, 0.338, and 0.56%, respectively, under AM 1.5 illumination.

Novel electrospun gas diffusion layers for polymer electrolyte membrane fuel cells: Part I. Fabrication, morphological characterization, and in situ performance

Science.gov (United States)

Chevalier, S.; Lavielle, N.; Hatton, B. D.; Bazylak, A.

2017-06-01

In this first of a series of two papers, we report an in-depth analysis of the impact of the gas diffusion layer (GDL) structure on the polymer electrolyte membrane (PEM) fuel cell performance through the use of custom GDLs fabricated in-house. Hydrophobic electrospun nanofibrous gas diffusion layers (eGDLs) are fabricated with controlled fibre diameter and alignment. The eGDLs are rendered hydrophobic through direct surface functionalization, and this molecular grafting is achieved in the absence of structural alteration. The fibre diameter, chemical composition, and electrical conductivity of the eGDL are characterized, and the impact of eGDL structure on fuel cell performance is analysed. We observe that the eGDL facilitates higher fuel cell power densities compared to a commercial GDL (Toray TGP-H-60) at highly humidified operating conditions. The ohmic resistance of the fuel cell is found to significantly increase with increasing inter-fiber distance. It is also observed that the addition of a hydrophobic treatment enhances membrane hydration, and fibres perpendicularly aligned to the channel direction may enhance the contact area between the catalyst layer and the GDL.

Aligned carbon nanotubes. Physics, concepts, fabrication and devices

Energy Technology Data Exchange (ETDEWEB)

Ren, Zhifeng; Lan, Yucheng [Boston College, Chestnut Hill, MA (United States). Dept. of Physics; Wang, Yang [South China Normal Univ. Guangzhou (China). Inst. for Advanced Materials

2013-07-01

This book gives a survey of the physics and fabrication of carbon nanotubes and their applications in optics, electronics, chemistry and biotechnology. It focuses on the structural characterization of various carbon nanotubes, fabrication of vertically or parallel aligned carbon nanotubes on substrates or in composites, physical properties for their alignment, and applications of aligned carbon nanotubes in field emission, optical antennas, light transmission, solar cells, chemical devices, bio-devices, and many others. Major fabrication methods are illustrated in detail, particularly the most widely used PECVD growth technique on which various device integration schemes are based, followed by applications such as electrical interconnects, nanodiodes, optical antennas, and nanocoax solar cells, whereas current limitations and challenges are also be discussed to lay the foundation for future developments.

Fabrication and electromagnetic interference shielding effectiveness of polymeric composites filled with silver-coated microorganism cells

Energy Technology Data Exchange (ETDEWEB)

Lan, Mingming, E-mail: lan_mingming@163.com [College of Mechanical and Electrical Engineering, Henan Agricultural University, Zhengzhou 450002 (China); Zhang, Deyuan; Cai, Jun; Hu, Yanyan; Yuan, Liming [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China)

2014-07-01

In this paper, helical silver-coated Spirulina cells were used as conductive fillers for the fabrication of polymeric composites. The morphology and composition of the coated Spirulina cells were analyzed with scanning electron microscope and energy dispersive X-ray spectrometer. The densities of silver-coated Spirulina cells were measured using the standard Archimedes method with distilled water. The electrical resistivity was measured by four-probe technique using ammeter and voltmeter whereas electromagnetic interference shielding effectiveness was measured by four-port method using vector network analyzer and coaxial-airline sample holder. The results showed that the silver-coated Spirulina cells with different coating thickness were lightweight fillers compared to the other typical conductive particles. The polymeric composites could achieve good conductivity at the lower content of silver-coated Spirulina cells owing to their helical shape. The shielding effectiveness of polymeric composites had a strong dependence on their conductivity. At the coating thickness of 0.96 μm and the content of 40 vol%, the shielding effectiveness could reach above 74.3 dB in entire test wave band.

Enhanced Efficiency of GaAs Single-Junction Solar Cells with Inverted-Cone-Shaped Nanoholes Fabricated Using Anodic Aluminum Oxide Masks

Directory of Open Access Journals (Sweden)

Kangho Kim

2013-01-01

Full Text Available The GaAs solar cells are grown by low-pressure metalorganic chemical vapor deposition (LP-MOCVD and fabricated by photolithography, metal evaporation, annealing, and wet chemical etch processes. Anodized aluminum oxide (AAO masks are prepared from an aluminum foil by a two-step anodization method. Inductively coupled plasma dry etching is used to etch and define the nanoarray structures on top of an InGaP window layer of the GaAs solar cells. The inverted-cone-shaped nanoholes with a surface diameter of about 50 nm are formed on the top surface of the solar cells after the AAO mask removal. Photovoltaic and optical characteristics of the GaAs solar cells with and without the nanohole arrays are investigated. The reflectance of the AAO nanopatterned samples is lower than that of the planar GaAs solar cell in the measured range. The short-circuit current density increased up to 11.63% and the conversion efficiency improved from 10.53 to 11.57% under 1-sun AM 1.5 G conditions by using the nanohole arrays. Dependence of the efficiency enhancement on the etching depth of the nanohole arrays is also investigated. These results show that the nanohole arrays fabricated with an AAO technique may be employed to improve the light absorption and, in turn, the conversion efficiency of the GaAs solar cell.

Selective deposition contact patterning using atomic layer deposition for the fabrication of crystalline silicon solar cells

International Nuclear Information System (INIS)

Cho, Young Joon; Shin, Woong-Chul; Chang, Hyo Sik

2014-01-01

Selective deposition contact (SDC) patterning was applied to fabricate the rear side passivation of crystalline silicon (Si) solar cells. By this method, using screen printing for contact patterning and atomic layer deposition for the passivation of Si solar cells with Al 2 O 3 , we produced local contacts without photolithography or any laser-based processes. Passivated emitter and rear-contact solar cells passivated with ozone-based Al 2 O 3 showed, for the SDC process, an up-to-0.7% absolute conversion-efficiency improvement. The results of this experiment indicate that the proposed method is feasible for conversion-efficiency improvement of industrial crystalline Si solar cells. - Highlights: • We propose a local contact formation process. • Local contact forms a screen print and an atomic layer deposited-Al 2 O 3 film. • Ozone-based Al 2 O 3 thin film was selectively deposited onto patterned silicon. • Selective deposition contact patterning method can increase cell-efficiency by 0.7%

Precise fabrication of X-band accelerating structure

International Nuclear Information System (INIS)

Higo, T.; Sakai, H.; Higashi, Y.; Koike, S.; Takatomi, T.

1994-01-01

An accelerating structure with a/λ=0.16 is being fabricated to study a precise fabrication method. A frequency control of each cell better than 10 -4 level is required to realize a detuned structure. The present machining level is nearly 1 MHz/11.4 GHz in relative frequency error, which just satisfies the above requirement. To keep this machining precision, the diffusion bonding technique is found preferable to join the cells. Various diffusion conditions were tried. The frequency change can be less than 1 MHz/11.4 GHz and it can be controlled well better than that. (author)

Solar cells with PbS quantum dot sensitized TiO2-multiwalled carbon nanotube composites, sulfide-titania gel and tin sulfide coated C-fabric.

Science.gov (United States)

Kokal, Ramesh K; Deepa, Melepurath; Kalluri, Ankarao; Singh, Shrishti; Macwan, Isaac; Patra, Prabir K; Gilarde, Jeff

2017-10-04

Novel approaches to boost quantum dot solar cell (QDSC) efficiencies are in demand. Herein, three strategies are used: (i) a hydrothermally synthesized TiO 2 -multiwalled carbon nanotube (MWCNT) composite instead of conventional TiO 2 , (ii) a counter electrode (CE) that has not been applied to QDSCs until now, namely, tin sulfide (SnS) nanoparticles (NPs) coated over a conductive carbon (C)-fabric, and (iii) a quasi-solid-state gel electrolyte composed of S 2- , an inert polymer and TiO 2 nanoparticles as opposed to a polysulfide solution based hole transport layer. MWCNTs by virtue of their high electrical conductivity and suitably positioned Fermi level (below the conduction bands of TiO 2 and PbS) allow fast photogenerated electron injection into the external circuit, and this is confirmed by a higher efficiency of 6.3% achieved for a TiO 2 -MWCNT/PbS/ZnS based (champion) cell, compared to the corresponding TiO 2 /PbS/ZnS based cell (4.45%). Nanoscale current map analysis of TiO 2 and TiO 2 -MWCNTs reveals the presence of narrowly spaced highly conducting domains in the latter, which equips it with an average current carrying capability greater by a few orders of magnitude. Electron transport and recombination resistances are lower and higher respectively for the TiO 2 -MWCNT/PbS/ZnS cell relative to the TiO 2 /PbS/ZnS cell, thus leading to a high performance cell. The efficacy of SnS/C-fabric as a CE is confirmed from the higher efficiency achieved in cells with this CE compared to the C-fabric based cells. Lower charge transfer and diffusional resistances, slower photovoltage decay, high electrical conductance and lower redox potential impart high catalytic activity to the SnS/C-fabric assembly for sulfide reduction and thus endow the TiO 2 -MWCNT/PbS/ZnS cell with a high open circuit voltage (0.9 V) and a large short circuit current density (∼20 mA cm -2 ). This study attempts to unravel how simple strategies can amplify QDSC performances.

Nanofiber membrane-electrode-assembly and method of fabricating same

Energy Technology Data Exchange (ETDEWEB)

Pintauro, Peter N.; Ballengee, Jason; Brodt, Matthew

2018-01-23

In one aspect of the present invention, a method of fabricating a fuel cell membrane-electrode-assembly (MEA) having an anode electrode, a cathode electrode, and a membrane disposed between the anode electrode and the cathode electrode, includes fabricating each of the anode electrode, the cathode electrode, and the membrane separately by electrospinning; and placing the membrane between the anode electrode and the cathode electrode, and pressing then together to form the fuel cell MEA.

Flexible inverted polymer solar cells with an indium-free tri-layer cathode

International Nuclear Information System (INIS)

El Hajj, Ahmad; Lucas, Bruno; Schirr-Bonnans, Martin; Ratier, Bernard; Kraft, Thomas M.; Torchio, Philippe

2014-01-01

Indium tin oxide (ITO)-free inverted polymer solar cells (PSCs) have been fabricated without the need of an additional electron transport layer. The indium-free transparent electrode consists of a tri-layer stack ZnO (30 nm)/Ag (14 nm)/ZnO (30 nm) deposited on glass and plastic substrates via ion-beam sputtering. The tri-layer electrodes exhibit similar physical properties to its ITO counterpart, specifically yielding high transmittance and low resistivity (76.5% T at 550 nm, R sq of 8 Ω/◻) on plastic substrates. The novel tri-layer electrode allows for the fabrication of inverted PSCs without the additional ZnO interfacial layer commonly deposited between ITO and the photoactive layer. This allows for the preparation of thinner plastic solar cells using less material than conventional architectures. Initial studies involving the newly realized architecture (tri-layer electrode/P3HT:PCBM/PEDOT:PSS/Ag) have shown great promise for the transition from ITO to other viable electrodes in organic electronics

Carbon-Ring Microelectrode Arrays for Electrochemical Imaging of Single Cell Exocytosis: Fabrication and Characterization

Science.gov (United States)

Lin, Yuqing; Trouillon, Raphaël; Svensson, Maria I.; Keighron, Jacqueline D.; Cans, Ann-Sofie; Ewing, Andrew G.

2012-01-01

Fabrication of carbon microelectrode arrays, with up to 15 electrodes in total tips as small as 10 to 50 μm, is presented. The support structures of microelectrodes were obtained by pulling multiple quartz capillaries together to form hollow capillary arrays before carbon deposition. Carbon ring microelectrodes were deposited by pyrolysis of acetylene in the lumen of these quartz capillary arrays. Each carbon deposited array tip was filled with epoxy, followed by beveling of the tip of the array to form a deposited carbon-ring microelectrode array (CRMA). Both the number of the microelectrodes in the array and the tip size are independently tunable. These CRMAs have been characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, and electrogenerated chemiluminescence. Additionally, the electrochemical properties were investigated with steady-state voltammetry. In order to demonstrate the utility of these fabricated microelectrodes in neurochemistry, CRMAs containing eight microring electrodes were used for electrochemical monitoring of exocytotic events from single PC12 cells. Subcellular temporal heterogeneities in exocytosis (ie. cold spots vs. hot spots) were successfully detected with the CRMAs. PMID:22339586

Single Cell Oil Production from Hydrolysates of Inulin by a Newly Isolated Yeast Papiliotrema laurentii AM113 for Biodiesel Making.

Science.gov (United States)

Wang, Guangyuan; Liu, Lin; Liang, Wenxing

2018-01-01

Microbial oils are among the most attractive alternative feedstocks for biodiesel production. In this study, a newly isolated yeast strain, AM113 of Papiliotrema laurentii, was identified as a potential lipid producer, which could accumulate a large amount of intracellular lipids from hydrolysates of inulin. P. laurentii AM113 was able to produce 54.6% (w/w) of intracellular oil in its cells and 18.2 g/l of dry cell mass in a fed-batch fermentation. The yields of lipid and biomass were 0.14 and 0.25 g per gram of consumed sugar, respectively. The lipid productivity was 0.092 g of oil per hour. Compositions of the fatty acids produced were C 14:0 (0.9%), C 16:0 (10.8%), C 16:1 (9.7%), C 18:0 (6.5%), C 18:1 (60.3%), and C 18:2 (11.8%). Biodiesel obtained from the extracted lipids could be burnt well. This study not only provides a promising candidate for single cell oil production, but will also probably facilitate more efficient biodiesel production.

Research on fabrication technology for thin film solar cells for practical use. Survey on the commercialization analysis; Usumaku taiyo denchi seizo gijutsu no jitsuyoka kenkyu. Jitsuyoka kaiseki ni kansuru chosa kenkyu

Energy Technology Data Exchange (ETDEWEB)

Tatsuta, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

1994-12-01

This paper reports the survey results on the technological trend, safety and latest technologies of thin film solar cells in fiscal 1994. As the fabrication technology for amorphous film solar cells, three-electrode plasma CVD was surveyed as fabrication method for high-mobility materials, and hydrogen radical CVD as fabrication method for high-photostable films. Current foreign and domestic reliability tests were surveyed for reliability evaluation of solar cells. In order to ascertain the performance, efficiency, physical properties and optimum structure of polycrystalline Si thin film solar cells, previously reported test results on physical properties such as carrier concentration, carrier lifetime and mobility of films were surveyed together with device simulation results. In addition, technologies for high-efficiency CuInSe2 system and CdTe system solar cells, technologies for cost reduction and mass production, and environmental influence were surveyed. Estimation of production costs for cell modules, and safety of thin film solar cells were also surveyed.

An Ethology of Urban Fabric(s)

DEFF Research Database (Denmark)

Fritsch, Jonas; Thomsen, Bodil Marie Stavning

2014-01-01

The article explores a non-metaphorical understanding of urban fabric(s), shifting the attention from a bird’s eye perspective to the actual, textural manifestations of a variety of urban fabric(s) to be studied in their real, processual, ecological and ethological complexity within urban life. We...... effectuate this move by bringing into resonance a range of intersecting fields that all deal with urban fabric(s) in complementary ways (interaction design and urban design activism, fashion, cultural theory, philosophy, urban computing)....

Fabrication of thin yttria-stabilized-zirconia dense electrolyte layers by inkjet printing for high performing solid oxide fuel cells

DEFF Research Database (Denmark)

Esposito, Vincenzo; Gadea, Christophe; Hjelm, Johan

2015-01-01

In this work, we present how a low-cost HP Deskjet 1000 inkjet printer was used to fabricate a 1.2 mm thin, dense and gas tight 16 cm2 solid oxide fuel cells (SOFC) electrolyte. The electrolyte was printed using an ink made of highly diluted (

Single source precursors for fabrication of I-III-VI{sub 2} thin-film solar cells via spray CVD

Energy Technology Data Exchange (ETDEWEB)

Hollingsworth, J.A.; Banger, K.K.; Jin, M.H.-C.; Harris, J.D.; Cowen, J.E.; Bohannan, E.W.; Switzer, J.A.; Buhro, W.E.; Hepp, A.F

2003-05-01

The development of thin-film solar cells on flexible, lightweight, space-qualified substrates provides an attractive cost solution to fabricating solar arrays with high specific power (W/kg). Thin-film fabrication studies demonstrate that ternary single source precursors can be used in either a hot, or cold-wall spray chemical vapour deposition reactor, for depositing CuInS{sub 2}, CuGaS{sub 2} and CuGaInS{sub 2} at reduced temperatures (400-450 sign C), which display good electrical and optical properties suitable for photovoltaic devices. X-ray diffraction studies, energy dispersive spectroscopy and scanning electron microscopy confirmed the formation of the single phase CIS, CGS, CIGS thin-films on various substrates at reduced temperatures.

The fabrication of front electrodes of Si solar cell by dispensing printing

International Nuclear Information System (INIS)

Kim, Do-Hyung; Ryu, Sung-Soo; Shin, Dongwook; Shin, Jung-Han; Jeong, Jwa-Jin; Kim, Hyeong-Jun; Chang, Hyo Sik

2012-01-01

Highlights: ► We propose the process for the front silver electrode by employing dispensing method. ► The dispensing method is a non-contact printing process. ► The electrode by dispensing method has more uniform and narrower shape. ► The dispensing method helped to enhance the efficiency of solar cell by 0.8% absolute. - Abstract: The dispensing printing was applied to fabricate the front electrodes of silicon solar cell. In this method, a micro channel nozzle and normal Ag paste were employed. The aspect ratio and line width of electrodes could be controlled by the process variables such as the inner diameter of nozzle, dispensing speed, discharge pressure, and the gap between wafer and nozzle. For the nozzle with the inner diameter of 50 μm, the line width and aspect ratio of electrode were under 90 μm and more than ∼0.2, respectively. When comparing the efficiency of solar cell prepared by conventional screen printing and the dispensing printing, the latter exhibited 19.1%, which is 0.8% absolute higher than the former even with the same Ag paste. This is because the electrode by dispensing printing has uniform aspect ratio and narrow line width over the length of electrode.

CMOS compatible fabrication of flexible and semi-transparent FeRAM on ultra-thin bulk monocrystalline silicon (100) fabric

KAUST Repository

Ghoneim, Mohamed T.; Hanna, Amir; Hussain, Muhammad Mustafa

2014-01-01

Commercialization of flexible electronics requires reliable, high performance, ultra-compact and low power devices. To achieve them, we fabricate traditional electronics on bulk mono-crystalline silicon (100) and transform the top portion into an ultra-thin flexible silicon fabric with prefabricated devices, preserving ultra-large-scale-integration density and same device performance. This can be done in a cost effective manner due to its full compatibility with standard CMOS processes. In this paper, using the same approach, for the first time we demonstrate a ferroelectric random access memory (FeRAM) cell on flexible silicon fabric platform and assess its functionality and practical potential.

CMOS compatible fabrication of flexible and semi-transparent FeRAM on ultra-thin bulk monocrystalline silicon (100) fabric

KAUST Repository

Ghoneim, Mohamed T.

2014-08-01

Commercialization of flexible electronics requires reliable, high performance, ultra-compact and low power devices. To achieve them, we fabricate traditional electronics on bulk mono-crystalline silicon (100) and transform the top portion into an ultra-thin flexible silicon fabric with prefabricated devices, preserving ultra-large-scale-integration density and same device performance. This can be done in a cost effective manner due to its full compatibility with standard CMOS processes. In this paper, using the same approach, for the first time we demonstrate a ferroelectric random access memory (FeRAM) cell on flexible silicon fabric platform and assess its functionality and practical potential.

A newly identified essential complex, Dre2-Tah18, controls mitochondria integrity and cell death after oxidative stress in yeast.

Directory of Open Access Journals (Sweden)

Laurence Vernis

Full Text Available A mutated allele of the essential gene TAH18 was previously identified in our laboratory in a genetic screen for new proteins interacting with the DNA polymerase delta in yeast [1]. The present work shows that Tah18 plays a role in response to oxidative stress. After exposure to lethal doses of H(2O(2, GFP-Tah18 relocalizes to the mitochondria and controls mitochondria integrity and cell death. Dre2, an essential Fe/S cluster protein and homologue of human anti-apoptotic Ciapin1, was identified as a molecular partner of Tah18 in the absence of stress. Moreover, Ciapin1 is able to replace yeast Dre2 in vivo and physically interacts with Tah18. Our results are in favour of an oxidative stress-induced cell death in yeast that involves mitochondria and is controlled by the newly identified Dre2-Tah18 complex.

Evaluation of cell viability and functionality in vessel-like bioprintable cell-laden tubular channels.

Science.gov (United States)

Yu, Yin; Zhang, Yahui; Martin, James A; Ozbolat, Ibrahim T

2013-09-01

Organ printing is a novel concept recently introduced in developing artificial three-dimensional organs to bridge the gap between transplantation needs and organ shortage. One of the major challenges is inclusion of blood-vessellike channels between layers to support cell viability, postprinting functionality in terms of nutrient transport, and waste removal. In this research, we developed a novel and effective method to print tubular channels encapsulating cells in alginate to mimic the natural vascular system. An experimental investigation into the influence on cartilage progenitor cell (CPCs) survival, and the function of printing parameters during and after the printing process were presented. CPC functionality was evaluated by checking tissue-specific genetic marker expression and extracellular matrix production. Our results demonstrated the capability of direct fabrication of cell-laden tubular channels by our newly designed coaxial nozzle assembly and revealed that the bioprinting process could induce quantifiable cell death due to changes in dispensing pressure, coaxial nozzle geometry, and biomaterial concentration. Cells were able to recover during incubation, as well as to undergo differentiation with high-level cartilage-associated gene expression. These findings may not only help optimize our system but also can be applied to biomanufacturing of 3D functional cellular tissue engineering constructs for various organ systems.

Fabrication and Characterization of Graded Anodes for Anode-Supported Solid Oxide Fuel Cells by Tape Casting and Lamination

DEFF Research Database (Denmark)

Beltran-Lopez, J.F.; Laguna-Bercero, M.A.; Gurauskis, Jonas

2014-01-01

Graded anodes for anode-supported solid oxide fuel cells (SOFCs) are fabricated by tape casting and subsequent cold lamination of plates using different compositions. Rheological parameters are adjusted to obtain stable suspensions for tape casting. The conditions for the tape casting and laminat......Graded anodes for anode-supported solid oxide fuel cells (SOFCs) are fabricated by tape casting and subsequent cold lamination of plates using different compositions. Rheological parameters are adjusted to obtain stable suspensions for tape casting. The conditions for the tape casting...... and lamination will be described. Flexural strength of the reduced cermets measured using three-point bending configuration is 468±37MPa. The graded anode supports are characterized by scanning electron microscope observations, mercury porosimetry intrusion, and resistivity measurements, showing an adequate...... of tapes at room temperature without using plasticizers. This is made by the combination of two different binders with varying Tg (glass transition temperature) which resulted in plastic deformation at room temperature. Those results indicate that the proposed process is a cost-effective method...

Does the presence of tumor-induced cortical bone destruction at CT have any prognostic value in newly diagnosed diffuse large B-cell lymphoma?

Energy Technology Data Exchange (ETDEWEB)

Adams, Hugo J.A.; Nievelstein, Rutger A.J.; Kwee, Thomas C. [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine, Utrecht (Netherlands); Klerk, John M.H. de [Meander Medical Center, Department of Nuclear Medicine, Amersfoort (Netherlands); Fijnheer, Rob [Meander Medical Center, Department of Hematology, Amersfoort (Netherlands); Heggelman, Ben G.F. [Meander Medical Center, Department of Radiology, Amersfoort (Netherlands); Dubois, Stefan V. [Meander Medical Center, Department of Pathology, Amersfoort (Netherlands)

2015-05-01

To determine the prognostic value of tumor-induced cortical bone destruction at computed tomography (CT) in newly diagnosed diffuse large B-cell lymphoma (DLBCL). This retrospective study included 105 patients with newly diagnosed DLBCL who had undergone CT and bone marrow biopsy (BMB) before R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin, Oncovin, and prednisolone) chemo-immunotherapy. Cox regression analyses were used to determine the associations of cortical bone status at CT (absence vs. presence of tumor-induced cortical bone destruction), BMB findings (negative vs. positive for lymphomatous involvement), and dichotomized National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) strata (low risk vs. high risk) with progression-free survival (PFS) and overall survival (OS). Univariate Cox regression analysis indicated that cortical bone status at CT was no significant predictor of either PFS or OS (p = 0.358 and p = 0.560, respectively), whereas BMB findings (p = 0.002 and p = 0.013, respectively) and dichotomized NCCN-IPI risk strata (p = 0.002 and p = 0.003, respectively) were significant predictors of both PFS and OS. In the multivariate Cox proportional hazards model, only the dichotomized NCCN-IPI score was an independent predictive factor of PFS and OS (p = 0.004 and p = 0.003, respectively). The presence of tumor-induced cortical bone destruction at CT was not found to have any prognostic implications in newly diagnosed DLBCL. (orig.)

High-Rate Fabrication of a-Si-Based Thin-Film Solar Cells Using Large-Area VHF PECVD Processes

Energy Technology Data Exchange (ETDEWEB)

Deng, Xunming [University of Toledo; Fan, Qi Hua

2011-12-31

The University of Toledo (UT), working in concert with it’s a-Si-based PV industry partner Xunlight Corporation (Xunlight), has conducted a comprehensive study to develop a large-area (3ft x 3ft) VHF PECVD system for high rate uniform fabrication of silicon absorber layers, and the large-area VHF PECVD processes to achieve high performance a-Si/a-SiGe or a-Si/nc-Si tandem junction solar cells during the period of July 1, 2008 to Dec. 31, 2011, under DOE Award No. DE-FG36-08GO18073. The project had two primary goals: (i) to develop and improve a large area (3 ft × 3 ft) VHF PECVD system for high rate fabrication of > = 8 Å/s a-Si and >= 20 Å/s nc-Si or 4 Å/s a-SiGe absorber layers with high uniformity in film thicknesses and in material structures. (ii) to develop and optimize the large-area VHF PECVD processes to achieve high-performance a-Si/nc-Si or a-Si/a-SiGe tandem-junction solar cells with >= 10% stable efficiency. Our work has met the goals and is summarized in “Accomplishments versus goals and objectives”.

Practicing on Newly Dead

Directory of Open Access Journals (Sweden)

Jewel Abraham

2015-07-01

Full Text Available A newly dead cadaver simulation is practiced on the physical remains of the dead before the onset of rigor mortis. This technique has potential benefits for providing real-life in-situ experience for novice providers in health care practices. Evolving ethical views in health care brings into question some of the ethical aspects associated with newly dead cadaver simulation in terms of justification for practice, autonomy, consent, and the need of disclosure. A clear statement of policies and procedures on newly dead cadaver simulation has yet to be implemented. Although there are benefits and disadvantages to an in-situ cadaver simulation, such practices should not be carried out in secrecy as there is no compelling evidence that suggests such training as imperative. Secrecy in these practices is a violation of honor code of nursing ethics. As health care providers, practitioners are obliged to be ethically honest and trustworthy to their patients. The author explores the ethical aspects of using newly dead cadaver simulation in training novice nursing providers to gain competency in various lifesaving skills, which otherwise cannot be practiced on a living individual. The author explores multiple views on cadaver simulation in relation to ethical theories and practices such as consent and disclosure to family.

Fabrication of fluorescent silica nanoparticles with aggregation-induced emission luminogens for cell imaging.

Science.gov (United States)

Chen, Sijie; Lam, Jacky W Y; Tang, Ben Zhong

2013-01-01

Fluorescence-based techniques have found wide applications in life science. Among various luminogenic materials, fluorescent nanoparticles have attracted much attention due to their fabulous emission properties and potential applications as sensors. Here, we describe the fabrication of fluorescent silica nanoparticles (FSNPs) containing aggregation-induced emission (AIE) luminogens. By employing surfactant-free sol-gel reaction, FSNPs with uniform size and high surface charge and colloidal stability are generated. The FSNPs emit strong light upon photoexcitation, due to the AIE characteristic of the silole -aggregates in the hybrid nanoparticles. The FSNPs are cytocompatible and can be utilized as fluorescent visualizer for intracellular imaging for HeLa cells.

Lowering data retention voltage in static random access memory array by post fabrication self-improvement of cell stability by multiple stress application

Science.gov (United States)

Mizutani, Tomoko; Takeuchi, Kiyoshi; Saraya, Takuya; Kobayashi, Masaharu; Hiramoto, Toshiro

2018-04-01

We propose a new version of the post fabrication static random access memory (SRAM) self-improvement technique, which utilizes multiple stress application. It is demonstrated that, using a device matrix array (DMA) test element group (TEG) with intrinsic channel fully depleted (FD) silicon-on-thin-buried-oxide (SOTB) six-transistor (6T) SRAM cells fabricated by the 65 nm technology, the lowering of data retention voltage (DRV) is more effectively achieved than using the previously proposed single stress technique.

Solid-state ZnS quantum dot-sensitized solar cell fabricated by the Dip-SILAR technique

International Nuclear Information System (INIS)

Mehrabian, M; Mirabbaszadeh, K; Afarideh, H

2014-01-01

Solid-state quantum dot sensitized solar cells (QDSSCs) were fabricated with zinc sulfide quantum dots (ZnS QDs), which served as the light absorber and the recombination blocking layer simultaneously. ZnS QDs were prepared successfully by a novel successive ionic layer adsorption and reaction technique based on dip-coating (Dip-SILAR). The dependences of the photovoltaic parameters on the number of SILAR cycles (n) were investigated. The cell with n = 6 (particle average size ∼9 nm) showed an energy conversion efficiency of 2.72% under the illumination of one sun (AM 1.5, 100 mW cm −2 ). Here we investigate also the cohesion between ZnS QDs and ZnO film to obtain a well-covering QD layer. (paper)

A Review on Fabricating Tissue Scaffolds using Vat Photopolymerization.

Science.gov (United States)

Chartrain, Nicholas A; Williams, Christopher B; Whittington, Abby R

2018-05-09

Vat Photopolymerization (stereolithography, SLA), an Additive Manufacturing (AM) or 3D printing technology, holds particular promise for the fabrication of tissue scaffolds for use in regenerative medicine. Unlike traditional tissue scaffold fabrication techniques, SLA is capable of fabricating designed scaffolds through the selective photopolymerization of a photopolymer resin on the micron scale. SLA offers unprecedented control over scaffold porosity and permeability, as well as pore size, shape, and interconnectivity. Perhaps even more significantly, SLA can be used to fabricate vascular networks that may encourage angio and vasculogenesis. Fulfilling this potential requires the development of new photopolymers, the incorporation of biochemical factors into printed scaffolds, and an understanding of the effects scaffold geometry have on cell viability, proliferation, and differentiation. This review compares SLA to other scaffold fabrication techniques, highlights significant advances in the field, and offers a perspective on the field's challenges and future directions. Engineering de novo tissues continues to be challenging due, in part, to our inability to fabricate complex tissue scaffolds that can support cell proliferation and encourage the formation of developed tissue. The goal of this review is to first introduce the reader to traditional and Additive Manufacturing scaffold fabrication techniques. The bulk of this review will then focus on apprising the reader of current research and provide a perspective on the promising use of vat photopolymerization (stereolithography, SLA) for the fabrication of complex tissue scaffolds. Copyright © 2018. Published by Elsevier Ltd.

Plastic Electronics and Optoelectronics: New Science and Technology from Soluble Semiconducting Polymers and Bulk Heterojunction Solar Cells Fabricated from Soluble Semiconducting Polymers

Science.gov (United States)

2011-11-03

Seifter, A. J. Heeger, Adv. Mater., 23, 1679–1683 (2011). 8. Efficient, Air-Stable Bulk Heterojunction Polymer Solar Cells Using MoOx as the Anode...distribution is unlimited. 13. SUPPLEMENTARY NOTES None 14. ABSTRACT Bulk heterojunction (BHJ) solar cells were invented at UC Santa Barbara after the...Bulk Heterojunction Solar Cells Fabricated from Soluble Semiconducting Polymers Grant number: AFOSR FA9550-08-1-0248 Dr. Charle Lee, Program

The fabrication and cell culture of three-dimensional rolled scaffolds with complex micro-architectures

International Nuclear Information System (INIS)

Liu Yaxiong; Li Xiao; Qu Xiaoli; Zhu Lin; He Jiankang; Zhao Qian; Wu Wanquan; Li Dichen

2012-01-01

Cell cultures for tissue engineering are traditionally prepared on two-dimensional or three-dimensional scaffolds with simple pores; however, this limits mass transportation, which is necessary for cell viability and function. In this paper, an innovative method is proposed for fabricating porous scaffolds with designed complex micro-architectures. Channels devised by computer-aided design were used to simulate features of blood vessels in native rat liver. Rapid prototyping and microreplication were used to produce a negative polydimethylsiloxane mold, and then a planar porous scaffold with predefined microchannel parameters was obtained by freeze-drying a silk fibroin/gelatin solution of an optimized concentration. After seeding with rat primary hepatocytes, the planar scaffold was rolled up to build spatial channels. By reconstructing the three-dimensional channel model in the scaffold in the form of micro-computed topography data and observing the cross-sections of the scroll, we confirmed that the bent channels were still interconnected, with restricted deviations. A comparison of the primary hepatocyte culture in the scaffolds with and without the devised channels proved that our design influenced cell organization and improved cell survival and proliferation. This method can be used for the construction of complex tissues for implantation and for culturing cells in vitro for biological tests and observations.

The Study of Fabric Performance for Car Seats

Directory of Open Access Journals (Sweden)

Antonin Havelka

2017-09-01

Full Text Available This paper deals with the investigation of the performance of car seat fabrics in terms of physiological comfort of sitting, specifi cally their water vapour resistance and air permeability. The current work presents an alternative approach to increasing the effectiveness of car seat fabrics through a combination of newly designed middle layer with forced convection achieved by a supplementary suction ventilation device. The supplementary device was designed to measure water vapour permeability by means of the sweating guarded hot plate (SGHP system. It consists of two parts: a frame to grip a tested sample for measurements within the SGHP system and two suction ventilators which are arranged at one end of the mentioned frame in order to provide suction into the tested fabric plane during the SGHP test. The results of this investigation show that water vapour transport is increased by approximately 20% compared to the standard way of measurement by means of SGHP because of forced air flow in the plane of ribbed – channelled structure of the car seat middle layer. The findings of this study have a number of important implications for future practice. The combination of a car seat cover with channelled structure and forced air fl ow improves physiological comfort of sitting which is a key issue for both drivers and manufacturers. The suggested device for forced air flow convection in the plane of a car seat fabric has not yet been part of an actual car seat, however it is possible to use its principles in a smart car seat prototype.

3D Photo-Fabrication for Tissue Engineering and Drug Delivery

Directory of Open Access Journals (Sweden)

Rúben F. Pereira

2015-03-01

Full Text Available The most promising strategies in tissue engineering involve the integration of a triad of biomaterials, living cells, and biologically active molecules to engineer synthetic environments that closely mimic the healing milieu present in human tissues, and that stimulate tissue repair and regeneration. To be clinically effective, these environments must replicate, as closely as possible, the main characteristics of the native extracellular matrix (ECM on a cellular and subcellular scale. Photo-fabrication techniques have already been used to generate 3D environments with precise architectures and heterogeneous composition, through a multi-layer procedure involving the selective photocrosslinking reaction of a light-sensitive prepolymer. Cells and therapeutic molecules can be included in the initial hydrogel precursor solution, and processed into 3D constructs. Recently, photo-fabrication has also been explored to dynamically modulate hydrogel features in real time, providing enhanced control of cell fate and delivery of bioactive compounds. This paper focuses on the use of 3D photo-fabrication techniques to produce advanced constructs for tissue regeneration and drug delivery applications. State-of-the-art photo-fabrication techniques are described, with emphasis on the operating principles and biofabrication strategies to create spatially controlled patterns of cells and bioactive factors. Considering its fast processing, spatiotemporal control, high resolution, and accuracy, photo-fabrication is assuming a critical role in the design of sophisticated 3D constructs. This technology is capable of providing appropriate environments for tissue regeneration, and regulating the spatiotemporal delivery of therapeutics.

Gene expression profiling for molecular classification of multiple myeloma in newly diagnosed patients

NARCIS (Netherlands)

Broyl, Annemiek; Hose, Dirk; Lokhorst, Henk; de Knegt, Yvonne; Peeters, Justine; Jauch, Anna; Bertsch, Uta; Buijs, Arjan; Stevens-Kroef, Marian; Beverloo, H. Berna; Vellenga, Edo; Zweegman, Sonja; Kersten, Marie-Josée; van der Holt, Bronno; el Jarari, Laila; Mulligan, George; Goldschmidt, Hartmut; van Duin, Mark; Sonneveld, Pieter

2010-01-01

To identify molecularly defined subgroups in multiple myeloma, gene expression profiling was performed on purified CD138(+) plasma cells of 320 newly diagnosed myeloma patients included in the Dutch-Belgian/German HOVON-65/GMMG-HD4 trial. Hierarchical clustering identified 10 subgroups; 6

Fabrication and performance of the Pt-Ru/Ni-P/FTO counter electrode for dye-sensitized solar cells

International Nuclear Information System (INIS)

Ma, Huanmei; Tian, Jianhua; Bai, Shuming; Liu, Xiaodong; Shan, Zhongqiang

2014-01-01

Highlights: • Pt-Ru alloy acts as the catalyst of counter electrodes in dye-sensitized solar cell. • Ni-P/FTO (fluorine-doped SnO 2 ) substrate is prepared by electroless plating method. • Pt-Ru/Ni-P/FTO counter electrode is fabricated by electrodeposition method. • The Ni-P sublayer improves the conductivity and light reflectance of FTO substrate. • The cell with Pt-Ru/Ni-P/FTO counter electrode exhibits an improved efficiency. - Abstract: In this paper, Pt-Ru/Ni-P/FTO has been designed and fabricated as the counter electrode for dye-sensitized solar cells. The Pt-Ru catalytic layer and Ni-P alloy sublayer are prepared by traditional electrodeposition method and a simple electroless plating method, respectively, and the preparation conditions have been optimized. The scanning electron microscopy (SEM) images show that the Pt-Ru particles are evenly distributed on FTO and Ni-P/FTO substrate. By X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), it is confirmed that the Ni-P amorphous alloy has been formed, and no other compounds involved Ni and P have been formed. The electrochemical measurement results reveal that the Pt-Ru electrode has higher catalytic activity and stability towards tri-iodine reduction reaction than Pt electrode in the organic medium. The Ni-P sublayer deposited on FTO glasses increases the conductivity and light-reflection ability of the counter electrode, and this contributes to lowering the inner resistance of the cell and improving the light utilization efficiency. Through the photovoltaic test, it is confirmed that the energy conversion efficiency of a single DSSC with the optimized Pt-Ru/Ni-P/FTO counter electrode is increased by 29% compared with that of the cell based on the Pt/FTO counter electrode under the same conditions

Fabrication and Optimization of Polymer Solar Cells Based on P3HT:PC70BM System

Directory of Open Access Journals (Sweden)

Huangzhong Yu

2016-01-01

Full Text Available Efficient bulk heterojunction (BHJ polymer solar cells (PSCs based on P3HT:PC70BM were fabricated by optimizing the processing parameters. The optimized thickness and annealing temperature have been found to be about 200 nm and 130°C. The effect of cathode interfacial layers on device performance is related to the formation of interfacial dipole. Furthermore, the effect of optimum ZnO interfacial thickness (~30 nm on device performance is attributed to good interfacial conductivity and its optical property. The metal electrode deposited in the slow rate has a better influence on device performance. Based on these optimal conditions, the best power conversion efficiency (PCE of 3.91% was obtained under AM 1.5G and 100 mW/cm2 illumination. This detailed investigation provides an important reference for the fabrication and optimization of polymer photovoltaic devices.

Multilayered sulphonated polysulfone/silica composite membranes for fuel cell applications

International Nuclear Information System (INIS)

Padmavathi, Rajangam; Karthikumar, Rajendhiran; Sangeetha, Dharmalingam

2012-01-01

Highlights: ► Multilayered membranes were fabricated with SPSu. ► Aminated polysulfone and silica were used as the layers in order to prevent the crossover of methanol. ► The methanol permeability and selectivity ratio proved a strong influence on DMFC application. ► The suitability of the multilayered membranes was studied in the lab made set-ups of PEMFC and DMFC. - Abstract: Polymer electrolyte membranes used in proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC) suffer from low dimensional stability. Hence multilayered membranes using sulfonated polysulfone (SPSu) and silica (SiO 2 ) were fabricated to alter such properties. The introduction of an SiO 2 layer between two layers of SPSu to form the multilayered composite membrane enhanced its dimensional stability, but slightly lowered its proton conductivity when compared to the conventional SPSu/SiO 2 composite membrane. Additionally, higher water absorption, lower methanol permeability and higher flame retardancy were also observed in this newly fabricated multilayered membrane. The performance evaluation of the 2 wt% SiO 2 loaded multilayered membrane in DMFC showed a maximum power density of 86.25 mW cm −2 , which was higher than that obtained for Nafion 117 membrane (52.8 mW cm −2 ) in the same single cell test assembly. Hence, due to the enhanced dimensional stability, reduced methanol permeability and higher maximum power density, the SPSu/SiO 2 /SPSu multilayered membrane can be a viable and a promising candidate for use as an electrolyte membrane in DMFC applications, when compared to Nafion.

Fabrication of ordered bulk heterojunction organic photovoltaic cells using nanopatterning and electrohydrodynamic spray deposition methods.

Science.gov (United States)

Park, Sung-Eun; Kim, Sehwan; Kim, Kangmin; Joe, Hang-Eun; Jung, Buyoung; Kim, Eunkyoung; Kim, Woochul; Min, Byung-Kwon; Hwang, Jungho

2012-12-21

Organic photovoltaic cells with an ordered heterojunction (OHJ) active layer are expected to show increased performance. In the study described here, OHJ cells were fabricated using a combination of nanoimprinting and electrohydrodynamic (EHD) spray deposition methods. After an electron donor material was nanoimprinted with a PDMS stamp (valley width: 230 nm, period: 590 nm) duplicated from a Si nanomold, an electron acceptor material was deposited onto the nanoimprinted donor layer using an EHD spray deposition method. The donor-acceptor interface layer was observed by obtaining cross-sectional images with a focused ion beam (FIB) microscope. The photocurrent generation performance of the OHJ cells was evaluated with the current density-voltage curve under air mass (AM) 1.5 conditions. It was found that the surface morphology of the electron acceptor layer affected the current and voltage outputs of the photovoltaic cells. When an electron acceptor layer with a smooth thin (250 nm above the valley of the electron donor layer) surface morphology was obtained, power conversion efficiency was as high as 0.55%. The electrohydrodynamic spray deposition method used to produce OHJ photovoltaic cells provides a means for the adoption of large area, high throughput processes.

Neural engineering from advanced biomaterials to 3D fabrication techniques

CERN Document Server

Kaplan, David

2016-01-01

This book covers the principles of advanced 3D fabrication techniques, stem cells and biomaterials for neural engineering. Renowned contributors cover topics such as neural tissue regeneration, peripheral and central nervous system repair, brain-machine interfaces and in vitro nervous system modeling. Within these areas, focus remains on exciting and emerging technologies such as highly developed neuroprostheses and the communication channels between the brain and prostheses, enabling technologies that are beneficial for development of therapeutic interventions, advanced fabrication techniques such as 3D bioprinting, photolithography, microfluidics, and subtractive fabrication, and the engineering of implantable neural grafts. There is a strong focus on stem cells and 3D bioprinting technologies throughout the book, including working with embryonic, fetal, neonatal, and adult stem cells and a variety of sophisticated 3D bioprinting methods for neural engineering applications. There is also a strong focus on b...

Reduction of bonding resistance of two-terminal III-V/Si tandem solar cells fabricated using smart-stack technology

Science.gov (United States)

Baba, Masaaki; Makita, Kikuo; Mizuno, Hidenori; Takato, Hidetaka; Sugaya, Takeyoshi; Yamada, Noboru

2017-12-01

This paper describes a method that remarkably reduces the bonding resistance of mechanically stacked two-terminal GaAs/Si and InGaP/Si tandem solar cells, where the top and bottom cells are bonded using a Pd nanoparticle array. A transparent conductive oxide (TCO) layer, which partially covers the surface of the Si bottom cell below the electrodes of the III-V top cell, significantly enhances the fill factor (FF) and cell conversion efficiency. The partial TCO layer reduces the bonding resistance and thus, increases the FF and efficiency of InGaP/Si by factors of 1.20 and 1.11, respectively. Eventually, the efficiency exceeds 15%. Minimizing the optical losses at the bonding interfaces of the TCO layer is important in the fabrication of high-efficiency solar cells. To help facilitate this, the optical losses in the tandem solar cells are thoroughly characterized through optical simulations and experimental verifications.

Fabrication and Testing of Deflecting Cavities for APS

Energy Technology Data Exchange (ETDEWEB)

Mammosser, John; Wang, Haipeng; Rimmer, Robert; Jim, Henry; Katherine, Wilson; Dhakal, Pashupati; Ali, Nassiri; Jim, Kerby; Jeremiah, Holzbauer; Genfa, Wu; Joel, Fuerst; Yawei, Yang; Zenghai, Li

2013-09-01

Jefferson Lab (Newport News, Virginia) in collaboration with Argonne National Laboratory (Argonne, IL) has fabricated and tested four first article, 2.8 GHz, deflecting SRF cavities, for Argonne's Short-Pulse X-ray (SPX) project. These cavities are unique in many ways including the fabrication techniques in which the cavity cell and waveguides were fabricated. These cavity subcomponents were milled from bulk large grain niobium ingot material directly from 3D CAD files. No forming of sub components was used with the exception of the beam-pipes. The challenging cavity and helium vessel design and fabrication results from the stringent RF performance requirements required by the project and operation in the APS ring. Production challenges and fabrication techniques as well as testing results will be discussed in this paper.

Newly graduated nurses' use of knowledge sources

DEFF Research Database (Denmark)

Voldbjerg, Siri Lygum; Grønkjaer, Mette; Sørensen, Erik Elgaard

2016-01-01

AIM: To advance evidence on newly graduated nurses' use of knowledge sources. BACKGROUND: Clinical decisions need to be evidence-based and understanding the knowledge sources that newly graduated nurses use will inform both education and practice. Qualitative studies on newly graduated nurses' use...... underscoring progression in knowledge use and perception of competence and confidence among newly graduated nurses. CONCLUSION: The transition phase, feeling of confidence and ability to use critical thinking and reflection, has a great impact on knowledge sources incorporated in clinical decisions....... The synthesis accentuates that for use of newly graduated nurses' qualifications and skills in evidence-based practice, clinical practice needs to provide a supportive environment which nurtures critical thinking and questions and articulates use of multiple knowledge sources....

Design, fabrication, and characterization of polymer based bulk heterojunction solar cells with enhanced efficiencies

Science.gov (United States)

Lu, Haiwei

Polymer based bulk heterojunction (BHJ) solar cells offer promising technological advantages for actualization of low-cost and large-area fabrication on flexible substrates. To reach the envisaged market entry figure of 10% power conversion efficiency (PCE), it is crucial that more solar energy is utilized in the active layer, requiring both higher energy conversion efficiency and expansion of the absorption spectrum of the active layer to near infrared (NIR) region. The research introduced in this dissertation is an effort to increase PCE of solar cells from the aforementioned two directions. In the first method, carbon nanotubes (CNTs) were incorporated into polymer-fullerene BHJ solar cells to increase the hole-collection efficiency. Devices with CNT monolayer networks placed at different positions were fabricated, and the impact of CNTs on device performance was studied. It was demonstrated that CNTs placed on the hole-collection side of the device resulted in optimized performance, with PCE increased from 4% to 4.9%. To realize the controlled deposition of a uniform layer of CNTs on different positions, a mild plasma treatment of the active-layer was employed, and the influence of plasma treatment on device performance was also studied. In the second strategy, I developed an approach to expand the absorption spectrum to NIR region. In this case, hybrid polymer based BHJ solar cells composed of pyridine-capped PbS (PbS-py) quantum dots (QDs) and poly(3-hexylthiophene) (P3HT) were proposed. With pyridines as capping ligands, devices showed superior performance compared to with conventionally used oleate agents. PbS QDs with bandgaps of ˜1.13-1.38 eV offered the advantage of energetically favorable charge separation between P3HT and PbS QDs for photoexcitons in both visible and NIR regions. It was also found that thermal annealing leads to the removal of excess and interfacial pyridine ligands in polymer/QDs composites, and thus provides intimate electrical

A sacrificial process for fabrication of biodegradable polymer membranes with submicron thickness.

Science.gov (United States)

Beardslee, Luke A; Stolwijk, Judith; Khaladj, Dimitrius A; Trebak, Mohamed; Halman, Justin; Torrejon, Karen Y; Niamsiri, Nuttawee; Bergkvist, Magnus

2016-08-01

A new sacrificial molding process using a single mask has been developed to fabricate ultrathin 2-dimensional membranes from several biocompatible polymeric materials. The fabrication process is similar to a sacrificial microelectromechanical systems (MEMS) process flow, where a mold is created from a material that can be coated with a biodegradable polymer and subsequently etched away, leaving behind a very thin polymer membrane. In this work, two different sacrificial mold materials, silicon dioxide (SiO2 ) and Liftoff Resist (LOR) were used. Three different biodegradable materials; polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and polyglycidyl methacrylate (PGMA), were chosen as model polymers. We demonstrate that this process is capable of fabricating 200-500 nm thin, through-hole polymer membranes with various geometries, pore-sizes and spatial features approaching 2.5 µm using a mold fabricated via a single contact photolithography exposure. In addition, the membranes can be mounted to support rings made from either SU8 or PCL for easy handling after release. Cell culture compatibility of the fabricated membranes was evaluated with human dermal microvascular endothelial cells (HDMECs) seeded onto the ultrathin porous membranes, where the cells grew and formed confluent layers with well-established cell-cell contacts. Furthermore, human trabecular meshwork cells (HTMCs) cultured on these scaffolds showed similar proliferation as on flat PCL substrates, further validating its compatibility. All together, these results demonstrated the feasibility of our sacrificial fabrication process to produce biocompatible, ultra-thin membranes with defined microstructures (i.e., pores) with the potential to be used as substrates for tissue engineering applications. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1192-1201, 2016. © 2015 Wiley Periodicals, Inc.

Fabrication of recyclable superhydrophobic cotton fabrics

Science.gov (United States)

Han, Sang Wook; Park, Eun Ji; Jeong, Myung-Geun; Kim, Il Hee; Seo, Hyun Ook; Kim, Ju Hwan; Kim, Kwang-Dae; Kim, Young Dok

2017-04-01

Commercial cotton fabric was coated with SiO2 nanoparticles wrapped with a polydimethylsiloxane (PDMS) layer, and the resulting material surface showed a water contact angle greater than 160°. The superhydrophobic fabric showed resistance to water-soluble contaminants and maintained its original superhydrophobic properties with almost no alteration even after many times of absorption-washing cycles of oil. Moreover, superhydrophobic fabric can be used as a filter to separate oil from water. We demonstrated a simple method of fabrication of superhydrophobic fabric with potential interest for use in a variety of applications.

Roll-to-Roll Fabricated Polymer Solar Cells: Towards Low Environmental Impact and Reporting Consensus

DEFF Research Database (Denmark)

Larsen-Olsen, Thue Trofod

The sun is by far the largest source of renewable energy available; consequently solar cells, which are able to convert light into electricity, have the technical potential to cover the global energy needs. Polymer solar cells (PSCs) on flexible plastic substrate have a low embodied energy and can...... be processed by fast roll-to-roll (R2R) methods, using earth abundant materials, and thus deliver the prospects to fulfil this potential. A strong polarization in PSC research efforts have led to diverging and non-comparable results: While very high power conversion efficiencies (PCEs) above 10% have been......, through R2R processing of tandem PSCs. A final focus area of the thesis is the investigation into the extrinsic variability in standard J-V characterizations done on PSCs, and towards ways to minimize it. Organic solvents are predominant process solvents used for fabricating the active layer of a PSC...

Rapid fabricating technique for multi-layered human hepatic cell sheets by forceful contraction of the fibroblast monolayer.

Directory of Open Access Journals (Sweden)

Yusuke Sakai

Full Text Available Cell sheet engineering is attracting attention from investigators in various fields, from basic research scientists to clinicians focused on regenerative medicine. However, hepatocytes have a limited proliferation potential in vitro, and it generally takes a several days to form a sheet morphology and multi-layered sheets. We herein report our rapid and efficient technique for generating multi-layered human hepatic cell (HepaRG® cell sheets using pre-cultured fibroblast monolayers derived from human skin (TIG-118 cells as a feeder layer on a temperature-responsive culture dish. Multi-layered TIG-118/HepaRG cell sheets with a thick morphology were harvested on day 4 of culturing HepaRG cells by forceful contraction of the TIG-118 cells, and the resulting sheet could be easily handled. In addition, the human albumin and alpha 1-antitrypsin synthesis activities of TIG-118/HepaRG cells were approximately 1.2 and 1.3 times higher than those of HepaRG cells, respectively. Therefore, this technique is considered to be a promising modality for rapidly fabricating multi-layered human hepatocyte sheets from cells with limited proliferation potential, and the engineered cell sheet could be used for cell transplantation with highly specific functions.

Fabrication of Polymeric Antireflection Film Manufactured by Anodic Aluminum Oxide Template on Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Jenn-Kai Tsai

2017-03-01

Full Text Available In this study, high energy conversion efficient dye-sensitized solar cells (DSSCs were successfully fabricated by attaching a double anti-reflection (AR layer, which is composed of a subwavelength moth-eye structured polymethyl methacrylate (PMMA film and a polydimethylsiloxane (PDMS film. An efficiency of up to 6.79% was achieved. The moth-eye structured PMMA film was fabricated by using an anodic aluminum oxide (AAO template which is simple, low-cost and scalable. The nano-pattern of the AAO template was precisely reproduced onto the PMMA film. The photoanode was composed of Titanium dioxide (TiO2 nanoparticles (NPs with a diameter of 25 nm deposited on the fluorine-doped tin oxide (FTO glass substrate and the sensitizer N3. The double AR layer was proved to effectively improve the short-circuit current density (JSC and conversion efficiency from 14.77 to 15.79 mA/cm2 and from 6.26% to 6.79%, respectively.

Fabrication, characterization and applications of iron selenide

Energy Technology Data Exchange (ETDEWEB)

Hussain, Raja Azadar, E-mail: hussainazadar@yahoo.com [Department of Chemistry, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Badshah, Amin [Department of Chemistry, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Lal, Bhajan [Department of Energy Systems Engineering, Sukkur Institute of Business Administration (Pakistan)

2016-11-15

This review article presents fabrication of FeSe by solid state reactions, solution chemistry routes, chemical vapor deposition, spray pyrolysis and chemical vapor transport. Different properties and applications such as crystal structure and phase transition, band structure, spectroscopy, superconductivity, photocatalytic activity, electrochemical sensing, and fuel cell activity of FeSe have been discussed. - Graphical abstract: Iron selenide can be synthesized by solid state reactions, chemical vapor deposition, solution chemistry routes, chemical vapor transport and spray pyrolysis. - Highlights: • Different fabrication methods of iron selenide (FeSe) have been reviewed. • Crystal structure, band structure and spectroscopy of FeSe have been discussed. • Superconducting, catalytic and fuel cell application of FeSe have been presented.

Design, fabrication and actuation of a MEMS-based image stabilizer for photographic cell phone applications

International Nuclear Information System (INIS)

Chiou, Jin-Chern; Hung, Chen-Chun; Lin, Chun-Ying

2010-01-01

This work presents a MEMS-based image stabilizer applied for anti-shaking function in photographic cell phones. The proposed stabilizer is designed as a two-axis decoupling XY stage 1.4 × 1.4 × 0.1 mm 3 in size, and adequately strong to suspend an image sensor for anti-shaking photographic function. This stabilizer is fabricated by complex fabrication processes, including inductively coupled plasma (ICP) processes and flip-chip bonding technique. Based on the special designs of a hollow handle layer and a corresponding wire-bonding assisted holder, electrical signals of the suspended image sensor can be successfully sent out with 32 signal springs without incurring damage during wire-bonding packaging. The longest calculated traveling distance of the stabilizer is 25 µm which is sufficient to resolve the anti-shaking problem in a three-megapixel image sensor. Accordingly, the applied voltage for the 25 µm moving distance is 38 V. Moreover, the resonant frequency of the actuating device with the image sensor is 1.123 kHz.

A Review on the Fabrication of Electrospun Polymer Electrolyte Membrane for Direct Methanol Fuel Cell

Directory of Open Access Journals (Sweden)

Hazlina Junoh

2015-01-01

Full Text Available Proton exchange membrane (PEM is an electrolyte which behaves as important indicator for fuel cell’s performance. Research and development (R&D on fabrication of desirable PEM have burgeoned year by year, especially for direct methanol fuel cell (DMFC. However, most of the R&Ds only focus on the parent polymer electrolyte rather than polymer inorganic composites. This might be due to the difficulties faced in producing good dispersion of inorganic filler within the polymer matrix, which would consequently reduce the DMFC’s performance. Electrospinning is a promising technique to cater for this arising problem owing to its more widespread dispersion of inorganic filler within the polymer matrix, which can reduce the size of the filler up to nanoscale. There has been a huge development on fabricating electrolyte nanocomposite membrane, regardless of the effect of electrospun nanocomposite membrane on the fuel cell’s performance. In this present paper, issues regarding the R&D on electrospun sulfonated poly (ether ether ketone (SPEEK/inorganic nanocomposite fiber are addressed.

One-Step Printable Perovskite Films Fabricated under Ambient Conditions for Efficient and Reproducible Solar Cells.

Science.gov (United States)

Jung, Yen-Sook; Hwang, Kyeongil; Heo, Youn-Jung; Kim, Jueng-Eun; Lee, Donmin; Lee, Cheol-Ho; Joh, Han-Ik; Yeo, Jun-Seok; Kim, Dong-Yu

2017-08-23

Despite the potential of roll-to-roll processing for the fabrication of perovskite films, the realization of highly efficient and reproducible perovskite solar cells (PeSCs) through continuous coating techniques and low-temperature processing is still challenging. Here, we demonstrate that efficient and reliable CH 3 NH 3 PbI 3 (MAPbI 3 ) films fabricated by a printing process can be achieved through synergetic effects of binary processing additives, N-cyclohexyl-2-pyrrolidone (CHP) and dimethyl sulfoxide (DMSO). Notably, these perovskite films are deposited from premixed perovskite solutions for facile one-step processing under a room-temperature and ambient atmosphere. The CHP molecules result in the uniform and homogeneous perovskite films even in the one-step slot-die system, which originate from the high boiling point and low vapor pressure of CHP. Meanwhile, the DMSO molecules facilitate the growth of perovskite grains by forming intermediate states with the perovskite precursor molecules. Consequently, fully printed PeSC based on the binary additive system exhibits a high PCE of 12.56% with a high reproducibility.

Fabrication and characterization of inverted organic solar cells using shuttle cock-type metal phthalocyanine and PCBM:P3HT

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Atsushi, E-mail: suzuki@mat.usp.ac.jp; Furukawa, Ryo, E-mail: suzuki@mat.usp.ac.jp; Akiyama, Tsuyoshi, E-mail: suzuki@mat.usp.ac.jp; Oku, Takeo, E-mail: suzuki@mat.usp.ac.jp [Department of Materials Science, The University of Shiga Prefecture 2500 Hassaka, Hikone, Shiga 522-8533 (Japan)

2015-02-27

Inverted organic solar cells using shuttle cock-type phthalocyanine, semiconducting polymer and fullerenes were fabricated and characterized. Photovoltaic and optical properties of the solar cells with inverted structures were investigated by optical absorption, current density-voltage characteristics. The photovoltaic properties of the tandem organic solar cell using titanyl phthalocyanine, vanadyl phthalocyanine, poly(3-hexylthiophene) (P3HT) and [6, 6]-phenyl C{sub 61}-butyric acid methyl ester (PCBM) were improved. Effect of annealing and solvent treatment on surface morphologies of the active layer was investigated. The photovoltaic mechanisms, energy levels and band gap of active layers were discussed for improvement of the photovoltaic performance.

Fabrication and characterization of inverted organic solar cells using shuttle cock-type metal phthalocyanine and PCBM:P3HT

International Nuclear Information System (INIS)

Suzuki, Atsushi; Furukawa, Ryo; Akiyama, Tsuyoshi; Oku, Takeo

2015-01-01

Inverted organic solar cells using shuttle cock-type phthalocyanine, semiconducting polymer and fullerenes were fabricated and characterized. Photovoltaic and optical properties of the solar cells with inverted structures were investigated by optical absorption, current density-voltage characteristics. The photovoltaic properties of the tandem organic solar cell using titanyl phthalocyanine, vanadyl phthalocyanine, poly(3-hexylthiophene) (P3HT) and [6, 6]-phenyl C 61 -butyric acid methyl ester (PCBM) were improved. Effect of annealing and solvent treatment on surface morphologies of the active layer was investigated. The photovoltaic mechanisms, energy levels and band gap of active layers were discussed for improvement of the photovoltaic performance

Fabrication of gas diffusion layer based on x-y robotic spraying technique for proton exchange membrane fuel cell application

International Nuclear Information System (INIS)

Sitanggang, Ramli; Mohamad, Abu Bakar; Daud, Wan Ramli Wan; Kadhum, Abdul Amir H.; Iyuke, S.E.

2009-01-01

The x-y robotic spraying technique developed in the Universiti Kebangsaan Malaysia is capable of fabricating various sizes of thickness and porosity of gas diffusion layer (GDL) used in the proton exchange membrane fuel cell (PEMFC). These parameters are obtained by varying the characteristic spray numbers of the robotic spraying machine. This investigation results were adequately represented with mathematical equations for hydrogen gas distribution in GDL. Volumetric modulus (M) parameter is used to determine the value of current density produced on the electrode of a single cell PEMFC. Thus the M parameter can be employed as indicator for a successful GDL fabrication. GDL type 4 has three variables of layer design that can be optimized to function as gas distributor, gas storage, flooding preventer on GDL surface, to evacuate water from the electrode and to control the electrical conductivity. The gas distribution in GDL was mathematically represented with average error of 15.5%. The M value of GDL type 4 according to the model was 0.22 cm 3 /s and yielded a current density of 750 A/m 2 .

A novel fabrication of MEH-PPV/Al:ZnO nanorod arrays based ordered bulk heterojunction hybrid solar cells

Energy Technology Data Exchange (ETDEWEB)

Malek, M.F., E-mail: firz_solarzelle@yahoo.com [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Sahdan, M.Z.; Mamat, M.H.; Musa, M.Z. [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Khusaimi, Z.; Husairi, S.S. [NANO-SciTech Centre (NST), Institute of Science (IOS), Universiti Teknologi MARA -UiTM, 40450 Shah Alam, Selangor (Malaysia); Md Sin, N.D. [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); Rusop, M. [NANO-ElecTronic Centre (NET), Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor (Malaysia); NANO-SciTech Centre (NST), Institute of Science (IOS), Universiti Teknologi MARA - UiTM, 40450 Shah Alam, Selangor (Malaysia)

2013-06-15

Vertically aligned Al:ZnO nanorod arrays has been used as window layer in the fabrication of ordered bulk heterojuction hybrid solar cells. The utilization of the nanorod arrays will enhance the electron transport in vertical direction and also for light harvesting applications for high performance devices. The performance of this hybrid polymer/metal oxide photovoltaic devices based on MEH-PPV [poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene)] and oriented Al:ZnO nanorod arrays is studied. The Al:ZnO nanorod arrays with a diameter of about 70–80 nm and thickness of approximately 500 nm were successfully grown on Al:ZnO-coated ITO substrate by sonicated sol–gel immersion technique. The photovoltaic performance of a short-circuit current density of 5.320 mA/cm{sup 2}, an open-circuit voltage of 195 mV and a fill factor of 27.71%, with a power conversion efficiency of about 0.287% under AM 1.5 illumination (100 mW/cm{sup 2}). To the best of our knowledge, preparation of aligned Al:ZnO nanorod arrays for this type of solar cell fabrication has not been reported by any research group.

Blazed vector grating liquid crystal cells with photocrosslinkable polymeric alignment films fabricated by one-step polarizer rotation method

Science.gov (United States)

Kawai, Kotaro; Kuzuwata, Mitsuru; Sasaki, Tomoyuki; Noda, Kohei; Kawatsuki, Nobuhiro; Ono, Hiroshi

2014-12-01

Blazed vector grating liquid crystal (LC) cells, in which the directors of low-molar-mass LCs are antisymmetrically distributed, were fabricated by one-step exposure of an empty glass cell inner-coated with a photocrosslinkable polymer LC (PCLC) to UV light. By adopting a LC cell structure, twisted nematic (TN) and homogeneous (HOMO) alignments were obtained in the blazed vector grating LC cells. Moreover, the diffraction efficiency of the blazed vector grating LC cells was greatly improved by increasing the thickness of the device in comparison with that of a blazed vector grating with a thin film structure obtained in our previous study. In addition, the diffraction efficiency and polarization states of ±1st-order diffracted beams from the resultant blazed vector grating LC cells were controlled by designing a blazed pattern in the alignment films, and these diffraction properties were well explained on the basis of Jones calculus and the elastic continuum theory of nematic LCs.

Fabricating microfluidic valve master molds in SU-8 photoresist

Science.gov (United States)

Dy, Aaron J.; Cosmanescu, Alin; Sluka, James; Glazier, James A.; Stupack, Dwayne; Amarie, Dragos

2014-05-01

Multilayer soft lithography has become a powerful tool in analytical chemistry, biochemistry, material and life sciences, and medical research. Complex fluidic micro-circuits require reliable components that integrate easily into microchips. We introduce two novel approaches to master mold fabrication for constructing in-line micro-valves using SU-8. Our fabrication techniques enable robust and versatile integration of many lab-on-a-chip functions including filters, mixers, pumps, stream focusing and cell-culture chambers, with in-line valves. SU-8 created more robust valve master molds than the conventional positive photoresists used in multilayer soft lithography, but maintained the advantages of biocompatibility and rapid prototyping. As an example, we used valve master molds made of SU-8 to fabricate PDMS chips capable of precisely controlling beads or cells in solution.

Fabricating microfluidic valve master molds in SU-8 photoresist

International Nuclear Information System (INIS)

Dy, Aaron J; Cosmanescu, Alin; Sluka, James; Glazier, James A; Amarie, Dragos; Stupack, Dwayne

2014-01-01

Multilayer soft lithography has become a powerful tool in analytical chemistry, biochemistry, material and life sciences, and medical research. Complex fluidic micro-circuits require reliable components that integrate easily into microchips. We introduce two novel approaches to master mold fabrication for constructing in-line micro-valves using SU-8. Our fabrication techniques enable robust and versatile integration of many lab-on-a-chip functions including filters, mixers, pumps, stream focusing and cell-culture chambers, with in-line valves. SU-8 created more robust valve master molds than the conventional positive photoresists used in multilayer soft lithography, but maintained the advantages of biocompatibility and rapid prototyping. As an example, we used valve master molds made of SU-8 to fabricate PDMS chips capable of precisely controlling beads or cells in solution. (technical note)

Fabrication of silicon solar cell with >18% efficiency using spin-on-film processing for phosphorus diffusion and SiO{sub 2}/graded index TiO{sub 2} anti-reflective coating

Energy Technology Data Exchange (ETDEWEB)

Lee, Yi-Yu; Ho, Wen-Jeng, E-mail: wjho@ntut.edu.tw; Yeh, Chien-Wu

2015-11-01

Highlights: • Employed SOF technology for both phosphorus diffusion and multi-layer ARCs. • Optical properties of TiO{sub 2}, SiO{sub 2}, and SiO{sub 2}/TiO{sub 2}/TiO{sub 2} films are characterized. • Photovoltaic performances of the fabricated solar cells are measured and compared. • An impressive efficiency of 18.25% was obtained by using the SOF processes. - Abstract: This study employed spin-on film (SOF) technology for the fabrication of phosphorus diffusion and multi-layer anti-reflective coatings (ARCs) with a graded index on silicon (Si) wafers. Low cost and high efficiency solar cells are important issues for the operating cost of a photovoltaic system. SOF technology for the fabrication of solar cells can be for the achievement of this goal. This study succeeded in the application of SOF technology in the preparation of both phosphorus diffusion and SiO{sub 2}/graded index TiO{sub 2} ARCs for Si solar cells. Optical properties of TiO{sub 2}, SiO{sub 2}, and multi-layer SiO{sub 2}/TiO{sub 2} deposition by SOF are characterized. Electrical and optical characteristics of the fabricated solar cells are measured and compared. An impressive efficiency of 18.25% was obtained by using the SOF processes.

Association of Sendai virion envelope and a mouse surface membrane polypeptide on newly infected cells: lack of association with H-2K/D or alteration of viral immunogenicity

International Nuclear Information System (INIS)

Zarling, D.A.; Miskimen, J.A.; Fan, D.P; Fujimoto, E.K.; Smith, P.K.

1982-01-01

The reagent N-succinimidyl 4-azidophenyl-1,3'-dithiopropionate (SADP) was synthesized and then coupled to purified Sendai virions by the amino-reactive end of the SADP molecule. This SADP-coupled virus was fused into the membranes of surface radioiodinated P815 cells, and target structures were allowed to form. Next, the photosensitive group on SADP was activated with ultraviolet light to covalently couple the viral proteins to any neighboring cell surface proteins. The cellular neighbors were isolated from detergent extracts of membrane proteins after immunoprecipitation with antibody specific for Sendai virion proteins. The covalent cross-links between the nonradioactive Sendai proteins and the radioiodinated cellular polypeptide neighbors were broken, and the host cell polypeptides were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and detected by autoradiography. One of these neighboring cellular proteins had an apparent m.w. of 17,000, and none was found with the characteristic size and tryptic map of either the H-2K or D gene products. Thus, the H-2K or D proteins are unlikely to be SADP- detectable neighbors of Sendai viral antigens recognized by CTL. In further experiments, the complexes of Sendai virion proteins crosslinked to cellular polypeptide neighbors were isolated from the membrane of newly infected cells and were shown to be able to stimulate CTL in vitro with approximately the same efficiency as uncross-linked Sendai virion proteins. Thus, Sendai viral proteins in the membrane of newly infected cells do not appear to be in highly immunogenic complexes with either H-2K/D or any other cellular proteins

Behavior of the potential-induced degradation of photovoltaic modules fabricated using flat mono-crystalline silicon cells with different surface orientations

Science.gov (United States)

Yamaguchi, Seira; Masuda, Atsushi; Ohdaira, Keisuke

2016-04-01

This paper deals with the dependence of the potential-induced degradation (PID) of flat, p-type mono-crystalline silicon solar cell modules on the surface orientation of solar cells. The investigated modules were fabricated from p-type mono-crystalline silicon cells with a (100) or (111) surface orientation using a module laminator. PID tests were performed by applying a voltage of -1000 V to shorted module interconnector ribbons with respect to an Al plate placed on the cover glass of the modules at 85 °C. A decrease in the parallel resistance of the (100)-oriented cell modules is more significant than that of the (111)-oriented cell modules. Hence, the performance of the (100)-oriented-cell modules drastically deteriorates, compared with that of the (111)-oriented-cell modules. This implies that (111)-oriented cells offer a higher PID resistance.

Response of murine bone marrow-derived mesenchymal stromal cells to dry-etched porous silicon scaffolds.

Science.gov (United States)

Hajj-Hassan, Mohamad; Khayyat-Kholghi, Maedeh; Wang, Huifen; Chodavarapu, Vamsy; Henderson, Janet E

2011-11-01

Porous silicon shows great promise as a bio-interface material due to its large surface to volume ratio, its stability in aqueous solutions and to the ability to precisely regulate its pore characteristics. In the current study, porous silicon scaffolds were fabricated from single crystalline silicon wafers by a novel xenon difluoride dry etching technique. This simplified dry etch fabrication process allows selective formation of porous silicon using a standard photoresist as mask material and eliminates the post-formation drying step typically required for the wet etching techniques, thereby reducing the risk of damaging the newly formed porous silicon. The porous silicon scaffolds supported the growth of primary cultures of bone marrow derived mesenchymal stromal cells (MSC) plated at high density for up to 21 days in culture with no significant loss of viability, assessed using Alamar Blue. Scanning electron micrographs confirmed a dense lawn of cells at 9 days of culture and the presence of MSC within the pores of the porous silicon scaffolds. Copyright © 2011 Wiley Periodicals, Inc.

Novel highly sensitive and wearable pressure sensors from conductive three-dimensional fabric structures

International Nuclear Information System (INIS)

Li, Jianfeng; Xu, Bingang

2015-01-01

Pressure sensors based on three-dimensional fabrics have all the excellent properties of the textile substrate: excellent compressibility, good air permeability and moisture transmission ability, which will find applications ranging from the healthcare industry to daily usage. In this paper, novel pressure sensors based on 3D spacer fabrics have been developed by a proposed multi-coating method. By this coating method, carbon black can be coated uniformly on the silicon elastomer which is attached and slightly cured on the 3D fabric surface beforehand. The as-made pressure sensors have good conductivity and can measure external pressure up to 283 kPa with an electrical conductivity range of 9.8 kΩ. The sensitivity of 3D fabric pressure sensors can be as high as 50.31×10 −3 kPa −1 , which is better than other textile based pressure sensors. When the as-made sensors are pressed, their electrical resistance will decrease because of more conductive connections and bending of fibers in the spacer layer. The sensing mechanism related to fiber bending has been explored by using an equivalent resistance model. The newly developed 3D sensor devices can be designed to exhibit different sensing performances by simply changing the structures of fabric substrate, which endows this kind of device more flexibility in related applications. (paper)

Characterization of newly isolated lytic bacteriophages active against Acinetobacter baumannii.

Directory of Open Access Journals (Sweden)

Maia Merabishvili

Full Text Available Based on genotyping and host range, two newly isolated lytic bacteriophages, myovirus vB_AbaM_Acibel004 and podovirus vB_AbaP_Acibel007, active against Acinetobacter baumannii clinical strains, were selected from a new phage library for further characterization. The complete genomes of the two phages were analyzed. Both phages are characterized by broad host range and essential features of potential therapeutic phages, such as short latent period (27 and 21 min, respectively, high burst size (125 and 145, respectively, stability of activity in liquid culture and low frequency of occurrence of phage-resistant mutant bacterial cells. Genomic analysis showed that while Acibel004 represents a novel bacteriophage with resemblance to some unclassified Pseudomonas aeruginosa phages, Acibel007 belongs to the well-characterized genus of the Phikmvlikevirus. The newly isolated phages can serve as potential candidates for phage cocktails to control A. baumannii infections.

Can the exposure of Apis mellifera (Hymenoptera, Apiadae) larvae to a field concentration of thiamethoxam affect newly emerged bees?

Science.gov (United States)

Friol, Priscila Sepúlveda; Catae, Aline Fernanda; Tavares, Daiana Antonia; Malaspina, Osmar; Roat, Thaisa Cristina

2017-10-01

The use of insecticides on crops can affect non-target insects, such as bees. In addition to the adult bees, larvae can be exposed to the insecticide through contaminated floral resources. Therefore, this study aimed to investigate the possible effects of the exposure of A. mellifera larvae to a field concentration of thiamethoxam (0.001 ng/μL thiamethoxam) on larval and pupal survival and on the percentage of adult emergence. Additionally, its cytotoxic effects on the digestive cells of midgut, Malpighian tubules cells and Kenyon cells of the brain of newly emerged A. mellifera bees were analyzed. The results showed that larval exposure to this concentration of thiamethoxam did not influence larval and pupal survival or the percentage of adult bee emergence. However, this exposure caused ultra-structural alterations in the target and non-target organs of newly emerged bees. The digestive cell of bees that were exposed to the insecticide exhibited a basal labyrinth without long and thin channels and compromised mitochondria. In Malpighian tubules cells, disorganized basal labyrinth, dilated mitochondria with a deformed shape and a loss of cristae, and disorganized microvilli were observed. The results showed that the exposed bees presented Kenyon cells with alterations in the nucleus and mitochondria. These alterations indicate possible tissue degeneration, demonstrating the cytotoxicity of thiamethoxam in the target and non-target organs of newly emerged bees. Such results suggest cellular organelle impairment that can compromise cellular function of the midgut cells, Malpighian tubules cells and Kenyon cells, and, consequently, can compromise the longevity of the bees of the whole colony. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of Ni-YSZ anodes for solid oxide fuel cells fabricated by suspension plasma spraying with axial feedstock injection

Science.gov (United States)

Metcalfe, Craig; Kuhn, Joel; Kesler, Olivera

2013-12-01

Composite Ni-Y0.15Zr0.85O1.925 anodes were fabricated by axial-injection suspension plasma spraying in open atmosphere conditions. The composition of the anode is controllable by adjustment of the plasma gas composition, stand-off distance, and suspension feed rate. The total porosity is controllable through the addition of carbon black to the suspension as a sacrificial pore-forming material as well as by adjustment of the suspension feed rate. The size of the NiO particles in suspension affects both the composition and total porosity, with larger NiO particles leading to increased Ni content and porosity in the deposited coatings. The surface roughness increases with a decrease of the in-flight droplet momentum, which results from both smaller NiO particles in suspension and the addition of low density pore-forming materials. A solid oxide fuel cell was fabricated with both electrodes and electrolyte fabricated by axial-injection plasma spraying. Peak power densities of 0.718 W cm-2 and 1.13 W cm-2 at 750 °C and 850 °C, respectively, were achieved.

A chemically defined culture medium containing Rho kinase inhibitor Y-27632 for the fabrication of stratified squamous epithelial cell grafts

International Nuclear Information System (INIS)

Aslanova, Afag; Takagi, Ryo; Yamato, Masayuki; Okano, Teruo; Yamamoto, Masakazu

2015-01-01

With the development of a culture method for stratified squamous epithelial cells, tissue-engineered epithelial cell sheets have been successfully applied as clinical cell grafts. However, the implementation of these cell sheets without the use of any animal-derived materials is highly desirable. In this study, Rho-associated protein kinase inhibitor Y-27632 was used to develop a chemically defined culture medium for the fabrication of stratified epithelial cell grafts consisting of human epidermal and oral keratinocytes, and the proliferation activity, cell morphology, and gene expressions of the keratinocytes were analyzed. The results of a colorimetric assay indicated that Y-27632 significantly promoted the proliferation of the keratinocytes in culture media both with and without fetal bovine serum (FBS), although there were no indications of Y-27632 efficacy on cell morphology and stratification of the keratinocytes in culture medium without any animal-derived materials. The results of quantitative RT-PCR revealed that gene expressions correlated with cell adhesion, cell–cell junction, proliferation markers, and stem/progenitor markers in cultured keratinocytes were not strongly affected by the addition of Y-27632 to the culture medium. Moreover, gene expressions of differentiation markers in stratified keratinocytes cultured in medium without FBS were nearly identical to those of keratinocytes co-cultured with 3T3 feeder cells. Interestingly, the expressions of differentiation markers in cultured stratified keratinocytes were suppressed by FBS, whereas they were reconstructed by either co-culture of a 3T3 feeder layer or addition of Y-27632 into the culture medium containing FBS. These findings indicate that Y-27632 is a useful supplement for the development of a chemically defined culture medium for fabrication of stratified epithelial cell grafts for clinical applications for the purpose of developing the culture medium with a lower risk of pathogen

A chemically defined culture medium containing Rho kinase inhibitor Y-27632 for the fabrication of stratified squamous epithelial cell grafts

Energy Technology Data Exchange (ETDEWEB)

Aslanova, Afag [Department of Surgery, Institute of Gastroenterology, Tokyo Women' s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666 (Japan); Institute of Advanced Biomedical Engineering and Science, Tokyo Women' s Medical University, TWIns, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666 (Japan); Takagi, Ryo; Yamato, Masayuki; Okano, Teruo [Institute of Advanced Biomedical Engineering and Science, Tokyo Women' s Medical University, TWIns, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666 (Japan); Yamamoto, Masakazu, E-mail: yamamoto.ige@twmu.ac.jp [Department of Surgery, Institute of Gastroenterology, Tokyo Women' s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666 (Japan)

2015-05-01

With the development of a culture method for stratified squamous epithelial cells, tissue-engineered epithelial cell sheets have been successfully applied as clinical cell grafts. However, the implementation of these cell sheets without the use of any animal-derived materials is highly desirable. In this study, Rho-associated protein kinase inhibitor Y-27632 was used to develop a chemically defined culture medium for the fabrication of stratified epithelial cell grafts consisting of human epidermal and oral keratinocytes, and the proliferation activity, cell morphology, and gene expressions of the keratinocytes were analyzed. The results of a colorimetric assay indicated that Y-27632 significantly promoted the proliferation of the keratinocytes in culture media both with and without fetal bovine serum (FBS), although there were no indications of Y-27632 efficacy on cell morphology and stratification of the keratinocytes in culture medium without any animal-derived materials. The results of quantitative RT-PCR revealed that gene expressions correlated with cell adhesion, cell–cell junction, proliferation markers, and stem/progenitor markers in cultured keratinocytes were not strongly affected by the addition of Y-27632 to the culture medium. Moreover, gene expressions of differentiation markers in stratified keratinocytes cultured in medium without FBS were nearly identical to those of keratinocytes co-cultured with 3T3 feeder cells. Interestingly, the expressions of differentiation markers in cultured stratified keratinocytes were suppressed by FBS, whereas they were reconstructed by either co-culture of a 3T3 feeder layer or addition of Y-27632 into the culture medium containing FBS. These findings indicate that Y-27632 is a useful supplement for the development of a chemically defined culture medium for fabrication of stratified epithelial cell grafts for clinical applications for the purpose of developing the culture medium with a lower risk of pathogen

Localization of foot-and-mouth disease - RNA synthesis on newly formed cellular smooth membranous vacuoles

International Nuclear Information System (INIS)

Polatnick, J.; Wool, S.H.

1982-01-01

Viral RNA synthesis in foot-and-mouth disease infected bovine kidney cell cultures was associated throughout the infectious period with newly formed smooth membranous vacuoles. Membrane formation was measured by choline uptake. The site of RNA synthesis was determined by electron microscopic examination of autoradiograms of incorporated [ 3 H] uridine. Both membrane formation and RNA synthesis became signifcant at 2.5 hours postinfection, but membrane formation increased steadily to 4.5 hours while RNA synthesis peaked at 3.5 hours. Percent density distributions of developed silver grains on autoradiograms showed that almost all RNA synthesis was concentrated on the smooth vacuoles of infected cells. Histogram analysis of grain density distributions established that the site of RNA synthesis was the vacuolar membrane. The newly formed smooth membrane-bound vacuoles were not seen to coalesce into the large vacuolated areas typical of poliovirus cytopathogenicity. (Author)

Localization of foot-and-mouth disease - RNA synthesis on newly formed cellular smooth membranous vacuoles

Energy Technology Data Exchange (ETDEWEB)

Polatnick, J.; Wool, S.H. (United States Department of Agriculture, Science and Education, Greenport, New York (USA). Agricultural Research, Plum Island Animal Disease Center)

1982-01-01

Viral RNA synthesis in foot-and-mouth disease infected bovine kidney cell cultures was associated throughout the infectious period with newly formed smooth membranous vacuoles. Membrane formation was measured by choline uptake. The site of RNA synthesis was determined by electron microscopic examination of autoradiograms of incorporated (/sup 3/H) uridine. Both membrane formation and RNA synthesis became signifcant at 2.5 hours postinfection, but membrane formation increased steadily to 4.5 hours while RNA synthesis peaked at 3.5 hours. Percent density distributions of developed silver grains on autoradiograms showed that almost all RNA synthesis was concentrated on the smooth vacuoles of infected cells. Histogram analysis of grain density distributions established that the site of RNA synthesis was the vacuolar membrane. The newly formed smooth membrane-bound vacuoles were not seen to coalesce into the large vacuolated areas typical of poliovirus cytopathogenicity.

Phase I/II Trial of Autologous Bone Marrow Stem Cell Transplantation with a Three-Dimensional Woven-Fabric Scaffold for Periodontitis

Directory of Open Access Journals (Sweden)

Shunsuke Baba

2016-01-01

Full Text Available Regenerative medicine is emerging as a promising option, but the potential of autologous stem cells has not been investigated well in clinical settings of periodontal treatment. In this clinical study, we evaluated the safety and efficacy of a new regenerative therapy based on the surgical implantation of autologous mesenchymal stem cells (MSCs with a biodegradable three-dimensional (3D woven-fabric composite scaffold and platelet-rich plasma (PRP. Ten patients with periodontitis, who required a surgical procedure for intrabony defects, were enrolled in phase I/II trial. Once MSCs were implanted in each periodontal intrabony defect, the patients were monitored during 36 months for a medical exam including laboratory tests of blood and urine samples, changes in clinical attachment level, pocket depth, and linear bone growth (LBG. All three parameters improved significantly during the entire follow-up period (p<0.0001, leading to an average LBG of 4.7 mm after 36 months. Clinical mobility measured by Periotest showed a decreasing trend after the surgery. No clinical safety problems attributable to the investigational MSCs were identified. This clinical trial suggests that the stem cell therapy using MSCs-PRP/3D woven-fabric composite scaffold may constitute a novel safe and effective regenerative treatment option for periodontitis.

JLab SRF Cavity Fabrication Errors, Consequences and Lessons Learned

International Nuclear Information System (INIS)

Marhauser, Frank

2011-01-01

Today, elliptical superconducting RF (SRF) cavities are preferably made from deep-drawn niobium sheets as pursued at Jefferson Laboratory (JLab). The fabrication of a cavity incorporates various cavity cell machining, trimming and electron beam welding (EBW) steps as well as surface chemistry that add to forming errors creating geometrical deviations of the cavity shape from its design. An analysis of in-house built cavities over the last years revealed significant errors in cavity production. Past fabrication flaws are described and lessons learned applied successfully to the most recent in-house series production of multi-cell cavities.

Fabrication of novel cryomill for synthesis of high purity metallic nanoparticles

Science.gov (United States)

Kumar, Nirmal; Biswas, Krishanu

2015-08-01

The successful preparation of free standing metal nanoparticles with high purity in bulk quantity is the pre-requisite for any potential application. This is possible by using ball milling at cryogenic temperature. However, the most of ball mills available in the market do not allow preparing high purity metal nanoparticles by this route. In addition, it is not possible to carry out in situ measurements of process parameters as well as diagnostic of the process. In the present investigation, we present a detailed study on the fabrication of a cryomill, which is capable of avoiding contaminations in the product. It also provides in situ measurements and diagnostic of the low temperature milling process. Online monitoring of the milling temperature and observation of ball motion are the important aspects in the newly designed mill. The nanoparticles prepared using this fabricated mill have been found to be free standing and also free from contaminations.

Facile and Scalable Fabrication of Highly Efficient Lead Iodide Perovskite Thin-Film Solar Cells in Air Using Gas Pump Method.

Science.gov (United States)

Ding, Bin; Gao, Lili; Liang, Lusheng; Chu, Qianqian; Song, Xiaoxuan; Li, Yan; Yang, Guanjun; Fan, Bin; Wang, Mingkui; Li, Chengxin; Li, Changjiu

2016-08-10

Control of the perovskite film formation process to produce high-quality organic-inorganic metal halide perovskite thin films with uniform morphology, high surface coverage, and minimum pinholes is of great importance to highly efficient solar cells. Herein, we report on large-area light-absorbing perovskite films fabrication with a new facile and scalable gas pump method. By decreasing the total pressure in the evaporation environment, the gas pump method can significantly enhance the solvent evaporation rate by 8 times faster and thereby produce an extremely dense, uniform, and full-coverage perovskite thin film. The resulting planar perovskite solar cells can achieve an impressive power conversion efficiency up to 19.00% with an average efficiency of 17.38 ± 0.70% for 32 devices with an area of 5 × 2 mm, 13.91% for devices with a large area up to 1.13 cm(2). The perovskite films can be easily fabricated in air conditions with a relative humidity of 45-55%, which definitely has a promising prospect in industrial application of large-area perovskite solar panels.

Fabrication of agarose concave petridish for 3D-culture microarray method for spheroids formation of hepatic cells.

Science.gov (United States)

Zhang, Binbin; Li, Yang; Wang, Gaoshang; Jia, Zhidong; Li, Haiyan; Peng, Qing; Gao, Yi

2018-04-19

Liver is one of the most important organ in the body. But there are many limitations about liver transplantation for liver failure. It is quite important to develop the xenogeneic biological liver for providing an alternation to transplantation or liver regeneration. In this paper, we proposed a method to construct a novel kind of agarose 3D-culture concave microwell array for spheroids formation of hepatic cells. Using the 3D printing method, the microwell array was fabricated with an overall size of 6.4 mm × 6.4 mm, containing 121 microwells with 400 μm width/400 μm thickness. By exploiting the Polydimethylsiloxane (PDMS) membranes as a bridge, we finally fabricated the agarose one. We co-cultured three types of liver cells with bionics design in the microwell arrays. Using the methods described above, the resulting co-formed hepatocyte spheroids maintained the high viability and stable liver-specific functions. This engineered agarose concave microwell array could be a potentially useful tool for forming the elements for biological liver support. After developing the complete system, we also would consider to scale up the application of this system. It will be not only applied to the therapy of human organ damage, but also to the development of disease models and drug screening models.

Rapid fabrication of mesoporous TiO2 thin films by pulsed fibre laser for dye sensitized solar cells

Science.gov (United States)

Hadi, Aseel; Alhabradi, Mansour; Chen, Qian; Liu, Hong; Guo, Wei; Curioni, Michele; Cernik, Robert; Liu, Zhu

2018-01-01

In this paper we demonstrate for the first time that a fibre laser with a wavelength of 1070 nm and a pulse width of milliseconds can be applied to generate mesoporous nanocrystalline (nc) TiO2 thin films on ITO coated glass in ambient atmosphere, by complete vaporisation of organic binder and inter-connection of TiO2 nanoparticles, without thermally damaging the ITO layer and the glass substrate. The fabrication of the mesoporous TiO2 thin films was achieved by stationary laser beam irradiation of 1 min. The dye sensitized solar cell (DSSC) with the laser-sintered TiO2 photoanode reached higher power conversion efficiency (PCE) of 3.20% for the TiO2 film thickness of 6 μm compared with 2.99% for the furnace-sintered. Electrochemical impedance spectroscopy studies revealed that the laser sintering under the optimised condition effectively decreased charge transfer resistance and increased electron lifetime of the TiO2 thin films. The use of the fibre laser with over 40% wall-plug efficiency offers an economically-feasible, industrial viable solution to the major challenge of rapid fabrication of large scale, mass production of mesoporous metal oxide thin film based solar energy systems, potentially for perovskite and monolithic tandem solar cells, in the future.

Low temperature fabrication of ZnO compact layer for high performance plastic dye-sensitized ZnO solar cells

International Nuclear Information System (INIS)

Hu Fangyi; Xia Yujing; Guan Zisheng; Yin Xiong; He Tao

2012-01-01

Highlights: ► ZnO compact layer is prepared via simple electrochemical method at low temperature. ► Compact layer can effectively block electron transfer from TCO to electrolyte. ► DSC PCE is improved by 17% when ZnO compact layer is introduced. ► Plastic DSCs with ZnO compact layer show a PCE of 3.29% under AM1.5 100 mW cm −2 . ► The above efficiency is comparable to that with high temperature sintering step. - Abstract: ZnO compact layer has been fabricated on transparent conducting oxide glass and plastic polymer substrates at low temperature via electrodeposition. The results of dark current and cyclic voltammetric measurements demonstrate that the compact layer can effectively reduce the short circuit from transparent conducting oxide to electrolyte in dye-sensitized ZnO solar cells, leading to an increase of open-circuit photovoltage and fill factor of the devices and, thereby, the power conversion efficiency. The resultant plastic dye-sensitized ZnO solar cell presents an efficiency of 3.29% under illumination of 100 mW cm −2 , AM 1.5G. This indicates that electrodeposition is a viable method to fabricate ZnO compact layer for high performance flexible devices.

A Review on the Fabrication of Electro spun Polymer Electrolyte Membrane for Direct Methanol Fuel Cell

International Nuclear Information System (INIS)

Junoh, H.; Jaafar, J.; Norddin, M.N.A.M.; Ismail, A.F.; Othman, M.H.D.; Rahman, M.A.; Yusof, N.; Salleh, W.N.W.; Junoh, H.; Jaafar, J.; Norddin, M.N.A.M.; Ismail, A.F.; Othman, M.H.D.; Rahman, M.A.; Yusof, N.; Salleh, W.N.W.; Hamid Ilbeygi, H.

2014-01-01

Proton exchange membrane (PEM) is an electrolyte which behaves as important indicator for fuel cell’s performance. Research and development (R and D) on fabrication of desirable PEM have burgeoned year by year, especially for direct methanol fuel cell (DMFC). However, most of the R and Ds only focus on the parent polymer electrolyte rather than polymer inorganic composites. This might be due to the difficulties faced in producing good dispersion of inorganic filler within the polymer matrix, which would consequently reduce the DMFC’s performance. Electro spinning is a promising technique to cater for this arising problem owing to its more widespread dispersion of inorganic filler within the polymer matrix, which can reduce the size of the filler up to nano scale. There has been a huge development on fabricating electrolyte nano composite membrane, regardless of the effect of electro spun nano composite membrane on the fuel cell’s performance. In this present paper, issues regarding the R and D on electro spun sulfonated poly (ether ether ketone) (SPEEK)/inorganic nano composite fiber are addressed.

Fabrication of perforated isoporous membranes via a transfer-free strategy: enabling high-resolution separation of cells.

Science.gov (United States)

Ou, Yang; Lv, Chang-Jiang; Yu, Wei; Mao, Zheng-Wei; Wan, Ling-Shu; Xu, Zhi-Kang

2014-12-24

Thin perforated membranes with ordered pores are ideal barriers for high-resolution and high-efficiency selective transport and separation of biological species. However, for self-assembled thin membranes with a thickness less than several micrometers, an additional step of transferring the membranes onto porous supports is generally required. In this article, we present a facile transfer-free strategy for fabrication of robust perforated composite membranes via the breath figure process, and for the first time, demonstrate the application of the membranes in high-resolution cell separation of yeasts and lactobacilli without external pressure, achieving almost 100% rejection of yeasts and more than 70% recovery of lactobacilli with excellent viability. The avoidance of the transfer step simplifies the fabrication procedure of composite membranes and greatly improves the membrane homogeneity. Moreover, the introduction of an elastic triblock copolymer increases the interfacial strength between the membrane and the support, and allows the preservation of composite membranes in a dry state. Such perforated ordered membranes can also be applied in other size-based separation systems, enabling new opportunities in bioseparation and biosensors.

Newly Homeless Youth Typically Return Home

OpenAIRE

Milburn, Norweeta G.; Rosenthal, Doreen; Rotheram-Borus, Mary Jane; Mallett, Shelley; Batterham, Philip; Rice, Eric; Solorio, Rosa

2007-01-01

165 newly homeless adolescents from Melbourne, Australia and 261 from Los Angeles, United States were surveyed and followed for two years. Most newly homeless adolescents returned home (70% U.S., 47% Australia) for significant amounts of time (39% U.S., 17% Australia more than 12 months) within two years of becoming homeless.

Solid freeform fabrication of biological materials

Science.gov (United States)

Wang, Jiwen

functionally graded materials. The volume and composition of the suspensions printed in droplets at a small area are controlled by the inkjet Cyan-Magenta-Yellow-Black color printing principle. The potential of this newly-developed method for fabricating FGMs with arbitrarily designed three-dimensional composition profiles is demonstrated. Sintering investigation focuses on dental porcelain and hydroxyapatite (HA) bodies. Proper sintering conditions have been established for dental porcelain bodies to maintain dimensional accuracy and to prevent slumping. For sintering of HA bodies, a novel approach for sintering of HA bodies at temperatures as low as 900°C has been developed. Low temperature sintering of HA bodies is critical for the success of fabricating functionally graded HA/Ti-6Al-4V materials for orthopedic implant applications because co-sintering of HA and Ti-4Al-4V at temperatures above 950°C can result in the formation of soluble tricalcium phosphate and severe oxidation of Ti-6Al4V. The low temperature sintering of nanocrystalline HA developed in this study, based on the morphology driven anisotropic crystal coarsening mechanism, opens up the opportunity to fabricate functionally graded HA/Ti-6Al-4V materials with no decomposition of HA and oxidation of Ti-6Al-4V and to improve the quality of HA coatings on Ti alloys.

Automatic Fabric Defect Detection with a Multi-Scale Convolutional Denoising Autoencoder Network Model.

Science.gov (United States)

Mei, Shuang; Wang, Yudan; Wen, Guojun

2018-04-02

Fabric defect detection is a necessary and essential step of quality control in the textile manufacturing industry. Traditional fabric inspections are usually performed by manual visual methods, which are low in efficiency and poor in precision for long-term industrial applications. In this paper, we propose an unsupervised learning-based automated approach to detect and localize fabric defects without any manual intervention. This approach is used to reconstruct image patches with a convolutional denoising autoencoder network at multiple Gaussian pyramid levels and to synthesize detection results from the corresponding resolution channels. The reconstruction residual of each image patch is used as the indicator for direct pixel-wise prediction. By segmenting and synthesizing the reconstruction residual map at each resolution level, the final inspection result can be generated. This newly developed method has several prominent advantages for fabric defect detection. First, it can be trained with only a small amount of defect-free samples. This is especially important for situations in which collecting large amounts of defective samples is difficult and impracticable. Second, owing to the multi-modal integration strategy, it is relatively more robust and accurate compared to general inspection methods (the results at each resolution level can be viewed as a modality). Third, according to our results, it can address multiple types of textile fabrics, from simple to more complex. Experimental results demonstrate that the proposed model is robust and yields good overall performance with high precision and acceptable recall rates.

Automatic Fabric Defect Detection with a Multi-Scale Convolutional Denoising Autoencoder Network Model

Directory of Open Access Journals (Sweden)

Shuang Mei

2018-04-01

Full Text Available Fabric defect detection is a necessary and essential step of quality control in the textile manufacturing industry. Traditional fabric inspections are usually performed by manual visual methods, which are low in efficiency and poor in precision for long-term industrial applications. In this paper, we propose an unsupervised learning-based automated approach to detect and localize fabric defects without any manual intervention. This approach is used to reconstruct image patches with a convolutional denoising autoencoder network at multiple Gaussian pyramid levels and to synthesize detection results from the corresponding resolution channels. The reconstruction residual of each image patch is used as the indicator for direct pixel-wise prediction. By segmenting and synthesizing the reconstruction residual map at each resolution level, the final inspection result can be generated. This newly developed method has several prominent advantages for fabric defect detection. First, it can be trained with only a small amount of defect-free samples. This is especially important for situations in which collecting large amounts of defective samples is difficult and impracticable. Second, owing to the multi-modal integration strategy, it is relatively more robust and accurate compared to general inspection methods (the results at each resolution level can be viewed as a modality. Third, according to our results, it can address multiple types of textile fabrics, from simple to more complex. Experimental results demonstrate that the proposed model is robust and yields good overall performance with high precision and acceptable recall rates.

Solid freeform-fabricated scaffolds designed to carry multicellular mesenchymal stem cell spheroids for cartilage regeneration

Directory of Open Access Journals (Sweden)

G-S Huang

2013-10-01

Full Text Available Three-dimensional (3D cellular spheroids have recently emerged as a new trend to replace suspended single cells in modern cell-based therapies because of their greater regeneration capacities in vitro. They may lose the 3D structure during a change of microenvironment, which poses challenges to their translation in vivo. Besides, the conventional microporous scaffolds may have difficulty in accommodating these relatively large spheroids. Here we revealed a novel design of microenvironment for delivering and sustaining the 3D spheroids. Biodegradable scaffolds with macroporosity to accommodate mesenchymal stem cell (MSC spheroids were made by solid freeform fabrication (SFF from the solution of poly(D,L-lactide-co-glycolide. Their internal surface was modified with chitosan following air plasma treatment in order to preserve the morphology of the spheroids. It was demonstrated that human MSC spheroids loaded in SFF scaffolds produced a significantly larger amount of cartilage-associated extracellular matrix in vitro and in NOD/SCID mice compared to single cells in the same scaffolds. Implantation of MSC spheroid-loaded scaffolds into the chondral defects of rabbit knees showed superior cartilage regeneration. This study establishes new perspectives in designing the spheroid-sustaining microenvironment within a tissue engineering scaffold for in vivo applications.

Theory and Examples of Mathematical Modeling for Fine Weave Pierced Fabric

Directory of Open Access Journals (Sweden)

ZHOU Yu-bo

2017-04-01

Full Text Available A mathematical abstraction and three-dimensional modeling method of three-dimensional woven fabric structure was developed for the fine weave pierced fabric, taking parametric continuity splines as the track function of tow. Based on the significant parameters of fine weave pierced fabric measured by MicroCT, eight kinds of the three-dimensional digital models of the fabric structure were established with two kinds of tow sections and four kinds of tow trajectory characteristic functions. There is a good agreement between the three-dimensional digital models and real fabric by comparing their structures and porosities. This mathematical abstraction and three-dimensional modeling method can be applied in micro models for sub unit cell and macro models for macroscopic scale fabrics, with high adaptability.

Biomimetic Materials and Fabrication Approaches for Bone Tissue Engineering.

Science.gov (United States)

Kim, Hwan D; Amirthalingam, Sivashanmugam; Kim, Seunghyun L; Lee, Seunghun S; Rangasamy, Jayakumar; Hwang, Nathaniel S

2017-12-01

Various strategies have been explored to overcome critically sized bone defects via bone tissue engineering approaches that incorporate biomimetic scaffolds. Biomimetic scaffolds may provide a novel platform for phenotypically stable tissue formation and stem cell differentiation. In recent years, osteoinductive and inorganic biomimetic scaffold materials have been optimized to offer an osteo-friendly microenvironment for the osteogenic commitment of stem cells. Furthermore, scaffold structures with a microarchitecture design similar to native bone tissue are necessary for successful bone tissue regeneration. For this reason, various methods for fabricating 3D porous structures have been developed. Innovative techniques, such as 3D printing methods, are currently being utilized for optimal host stem cell infiltration, vascularization, nutrient transfer, and stem cell differentiation. In this progress report, biomimetic materials and fabrication approaches that are currently being utilized for biomimetic scaffold design are reviewed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabrication and characterization of UV-emitting nanoparticles as novel radiation sensitizers targeting hypoxic tumor cells

Science.gov (United States)

Squillante, Michael R.; Jüstel, Thomas; Anderson, R. Rox; Brecher, Charles; Chartier, Daniel; Christian, James F.; Cicchetti, Nicholas; Espinoza, Sara; McAdams, Daniel R.; Müller, Matthias; Tornifoglio, Brooke; Wang, Yimin; Purschke, Martin

2018-06-01

Radiation therapy is one of the primary therapeutic techniques for treating cancer, administered to nearly two-thirds of all cancer patients. Although largely effective in killing cancer cells, radiation therapy, like other forms of cancer treatment, has difficulty dealing with hypoxic regions within solid tumors. The incomplete killing of cancer cells can lead to recurrence and relapse. The research presented here is investigating the enhancement of the efficacy of radiation therapy by using scintillating nanoparticles that emit UV photons. UV photons, with wavelengths between 230 nm and 280 nm, are able to inactivate cells due to their direct interaction with DNA, causing a variety of forms of damage. UV-emitting nanoparticles will enhance the treatment in two ways: first by generating UV photons in the immediate vicinity of cancer cells, leading to direct and oxygen-independent DNA damage, and second by down-converting the applied higher energy X-rays into softer X-rays and particles that are more efficiently absorbed in the targeted tumor region. The end result will be nanoparticles with a higher efficacy in the treatment of hypoxic cells in the tumor, filling an important, unmet clinical need. Our preliminary experiments show an increase in cell death using scintillating LuPO4:Pr nanoparticles over that achieved by the primary radiation alone. This work describes the fabrication of the nanoparticles, their physical characterization, and the spectroscopic characterization of the UV emission. The work also presents in vitro results that demonstrate an enhanced efficacy of cell killing with x-rays and a low unspecific toxicity of the nanoparticles.

Fabrication of Thermo-Responsive Molecular Layers from Self-Assembling Elastin-Like Oligopeptides Containing Cell-Binding Domain for Tissue Engineering

Directory of Open Access Journals (Sweden)

Tomoyuki Koga

2015-01-01

Full Text Available Novel thermo-responsive elastin-like oligopeptides containing cell-binding epitope (Arg-Gly-Asp-Ser sequence; arginine-glycine-aspartic acid-serine (RGDS-elastin-like peptides (ELP and RGDS-deg-ELP; were newly prepared as building blocks of self-assembled molecular layer for artificial extra cellular matrix. A detailed analysis of the conformation of the oligo(ELPs in water and their self-assembling behavior onto hydrophobic surfaces were performed by using circular dichroism, Fourier transform infrared spectroscopy (FTIR, atomic force microscopy and water contact angle measurements. The experimental results revealed that both oligo(ELPs self-assembled onto hydrophobic surfaces and formed molecular layers based on their thermo-responsive conformational change from hydrous random coil to dehydrated β-turn structure. Effective cell adhesion and spreading behaviors were observed on these self-assembled oligo(ELP layers. In addition, attached cells were found to be recovered successfully as a cell-sheet by temperature-induced disassembly of oligo(ELP layer. This achievement provides an important insight to construct novel oligopeptide-based nano-surfaces for the design of smart artificial extra-cellular matrix.

Novel Solvent-free Perovskite Deposition in Fabrication of Normal and Inverted Architectures of Perovskite Solar Cells

Science.gov (United States)

Nejand, Bahram Abdollahi; Gharibzadeh, Saba; Ahmadi, Vahid; Shahverdi, H. Reza

2016-01-01

We introduced a new approach to deposit perovskite layer with no need for dissolving perovskite precursors. Deposition of Solution-free perovskite (SFP) layer is a key method for deposition of perovskite layer on the hole or electron transport layers that are strongly sensitive to perovskite precursors. Using deposition of SFP layer in the perovskite solar cells would extend possibility of using many electron and hole transport materials in both normal and invert architectures of perovskite solar cells. In the present work, we synthesized crystalline perovskite powder followed by successful deposition on TiO2 and cuprous iodide as the non-sensitve and sensitive charge transport layers to PbI2 and CH3NH3I solution in DMF. The post compressing step enhanced the efficiency of the devices by increasing the interface area between perovskite and charge transport layers. The 9.07% and 7.71% cell efficiencies of the device prepared by SFP layer was achieved in respective normal (using TiO2 as a deposition substrate) and inverted structure (using CuI as deposition substrate) of perovskite solar cell. This method can be efficient in large-scale and low cost fabrication of new generation perovskite solar cells. PMID:27640991

Development of high-power laser technology. Fabrication of a dye cell of the high power dye laser and development of the measurement technology of the fluid velocities in a dye cell

Energy Technology Data Exchange (ETDEWEB)

Jo, Jae Heung; Chang, Soo; Lim, Kwon; Kim, Jee Teak; Choi, Wan Hae [Hannam University, Taejon (Korea, Republic of)

1995-08-01

The computer simulation code for the simulation of the steady-state flow in a dye cell is developed by using the finite element method. The situation of the fluid flow is measured by the diode laser LDV system and compared with results of the computer simulation. The small size Fiber-Optic LDV with a directional coupler is designed and fabricated for the real time measurement of fluid velocities in a dye cell. (author). 13 refs.

Route to one-step microstructure mold fabrication for PDMS microfluidic chip

Science.gov (United States)

Lv, Xiaoqing; Geng, Zhaoxin; Fan, Zhiyuan; Wang, Shicai; Su, Yue; Fang, Weihao; Pei, Weihua; Chen, Hongda

2018-04-01

The microstructure mold fabrication for PDMS microfluidic chip remains complex and time-consuming process requiring special equipment and protocols: photolithography and etching. Thus, a rapid and cost-effective method is highly needed. Comparing with the traditional microfluidic chip fabricating process based on the micro-electromechanical system (MEMS), this method is simple and easy to implement, and the whole fabrication process only requires 1-2 h. Different size of microstructure from 100 to 1000 μm was fabricated, and used to culture four kinds of breast cancer cell lines. Cell viability and morphology was assessed when they were cultured in the micro straight channels, micro square holes and the bonding PDMS-glass microfluidic chip. The experimental results indicate that the microfluidic chip is good and meet the experimental requirements. This method can greatly reduce the process time and cost of the microfluidic chip, and provide a simple and effective way for the structure design and in the field of biological microfabrications and microfluidic chips.

Impaired mastication reduced newly generated neurons at the accessory olfactory bulb and pheromonal responses in mice.

Science.gov (United States)

Utsugi, Chizuru; Miyazono, Sadaharu; Osada, Kazumi; Matsuda, Mitsuyoshi; Kashiwayanagi, Makoto

2014-12-01

A large number of neurons are generated at the subventricular zone (SVZ) even during adulthood. In a previous study, we have shown that a reduced mastication impairs both neurogenesis in the SVZ and olfactory functions. Pheromonal signals, which are received by the vomeronasal organ, provide information about reproductive and social states. Vomeronasal sensory neurons project to the accessory olfactory bulb (AOB) located on the dorso-caudal surface of the main olfactory bulb. Newly generated neurons at the SVZ migrate to the AOB and differentiate into granule cells and periglomerular cells. This study aimed to explore the effects of changes in mastication on newly generated neurons and pheromonal responses. Bromodeoxyuridine-immunoreactive (BrdU-ir; a marker of DNA synthesis) and Fos-ir (a marker of neurons excited) structures in sagittal sections of the AOB after exposure to urinary odours were compared between the mice fed soft and hard diets. The density of BrdU-ir cells in the AOB in the soft-diet-fed mice after 1 month was essentially similar to that of the hard-diet-fed mice, while that was lower in the soft-diet-fed mice for 3 or 6 months than in the hard-diet-fed mice. The density of Fos-ir cells in the soft-diet-fed mice after 2 months was essentially similar to that in the hard-diet-fed mice, while that was lower in the soft-diet-fed mice for 4 months than in the hard-diet-fed mice. The present results suggest that impaired mastication reduces newly generated neurons at the AOB, which in turn impairs olfactory function at the AOB. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of thermal budget in n-type bifacial solar cell fabrication processes on effective lifetime of crystalline silicon

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Tomihisa Tachibana

2017-04-01

Full Text Available The effects of residual C on cell properties are investigated from the view point of thermal budget in the n-type bifacial cell processes. Implied Voc obtained from wafers with same Oi concentration depend on the thermal budgets decreases as the Cs concentration increases. The Voc values vary depending on the wafer with different growth cooling rate. To analyze the effect of thermal budget correspond to solar cell fabrication process, CZ wafers with almost the same Oi concentrations are prepared. One of the wafers with relatively high residual Cs concentration shows the longer lifetime than the initial value after the 950 oC annealing step. On the other hand, the lifetime of a wafer with relatively low Cs concentration dramatically decreased by the same process due to the O segregation. These results suggest that it is important to choose appropriate wafer specification, starting with feedstock material, for increasing the solar cell efficiency.

Fabrication of orderly nanostructured PLGA scaffolds using anodic aluminum oxide templates.

Science.gov (United States)

Wang, Gou-Jen; Lin, Yan-Cheng; Li, Ching-Wen; Hsueh, Cheng-Chih; Hsu, Shan-Hui; Hung, Huey-Shan

2009-08-01

In this research, two simple fabrication methods to fabricate orderly nanostructured PLGA scaffolds using anodic aluminum oxide (AAO) template were conducted. In the vacuum air-extraction approach, the PLGA solution was cast on an AAO template first. The vacuum air-extraction process was then applied to suck the semi-congealed PLGA into the nanopores of the AAO template to form a bamboo sprouts array of PLGA. The surface roughness of the nanostructured scaffolds, ranging from 20 nm to 76 nm, can be controlled by the sucking time of the vacuum air-extraction process. In the replica molding approach, the PLGA solution was cast on the orderly scraggy barrier-layer surface of an AAO membrane to fabricate a PLGA scaffold of concave nanostructure. Cell culture experiments using the bovine endothelial cells (BEC) demonstrated that the nanostructured PLGA membrane can increase the cell growing rate, especially for the bamboo sprouts array scaffolds with smaller surface roughness.

CTSH regulates β-cell function and disease progression in newly diagnosed type 1 diabetes patients

DEFF Research Database (Denmark)

Fløyel, Tina; Brorsson, Caroline; Nielsen, Lotte B

2014-01-01

expression and increased insulin secretion. Additionally, islets from Ctsh(-/-) mice contained less insulin than islets from WT mice. Importantly, the TT genotype was associated with higher daily insulin dose and faster disease progression in newly diagnosed T1D patients, indicating agreement between...

Quantification of newly produced B and T lymphocytes in untreated chronic lymphocytic leukemia patients

Directory of Open Access Journals (Sweden)

Caimi Luigi

2010-11-01

Full Text Available Abstract Background The immune defects occurring in chronic lymphocytic leukemia are responsible for the frequent occurrence of infections and autoimmune phenomena, and may be involved in the initiation and maintenance of the malignant clone. Here, we evaluated the quantitative defects of newly produced B and T lymphocytes. Methods The output of B and T lymphocytes from the production and maturation sites was analyzed in chronic lymphocytic leukemia patients and healthy controls by quantifying kappa-deleting recombination excision circles (KRECs and T-cell receptor excision circles (TRECs by a Real-Time PCR assay that simultaneously detects both targets. T-lymphocyte subsets were analyzed by six-color flow cytometric analysis. Data comparison was performed by two-sided Mann-Whitney test. Results KRECs level was reduced in untreated chronic lymphocytic leukemia patients studied at the very early stage of the disease, whereas the release of TRECs+ cells was preserved. Furthermore, the observed increase of CD4+ lymphocytes could be ascribed to the accumulation of CD4+ cells with effector memory phenotype. Conclusions The decreased number of newly produced B lymphocytes in these patients is likely related to a homeostatic mechanism by which the immune system balances the abnormal B-cell expansion. This feature may precede the profound defect of humoral immunity characterizing the later stages of the disease.

Fabrication of heterojunction solar cells by using microcrystalline hydrogenated silicon oxide film as an emitter

International Nuclear Information System (INIS)

Banerjee, Chandan; Sritharathikhun, Jaran; Konagai, Makoto; Yamada, Akira

2008-01-01

Wide gap, highly conducting n-type hydrogenated microcrystalline silicon oxide (μc-SiO : H) films were prepared by very high frequency plasma enhanced chemical vapour deposition at a very low substrate temperature (170 deg. C) as an alternative to amorphous silicon (a-Si : H) for use as an emitter layer of heterojunction solar cells. The optoelectronic properties of n-μc-SiO : H films prepared for the emitter layer are dark conductivity = 0.51 S cm -1 at 20 nm thin film, activation energy = 23 meV and E 04 = 2.3 eV. Czochralski-grown 380 μm thick p-type (1 0 0) oriented polished silicon wafers with a resistivity of 1-10 Ω cm were used for the fabrication of heterojunction solar cells. Photovoltaic parameters of the device were found to be V oc = 620 mV, J sc = 32.1 mA cm -2 , FF = 0.77, η = 15.32% (active area efficiency)

Recent Progress of Fabrication of Cell Scaffold by Electrospinning Technique for Articular Cartilage Tissue Engineering

Directory of Open Access Journals (Sweden)

Yingge Zhou

2018-01-01

Full Text Available As a versatile nanofiber manufacturing technique, electrospinning has been widely employed for the fabrication of tissue engineering scaffolds. Since the structure of natural extracellular matrices varies substantially in different tissues, there has been growing awareness of the fact that the hierarchical 3D structure of scaffolds may affect intercellular interactions, material transportation, fluid flow, environmental stimulation, and so forth. Physical blending of the synthetic and natural polymers to form composite materials better mimics the composition and mechanical properties of natural tissues. Scaffolds with element gradient, such as growth factor gradient, have demonstrated good potentials to promote heterogeneous cell growth and differentiation. Compared to 2D scaffolds with limited thicknesses, 3D scaffolds have superior cell differentiation and development rate. The objective of this review paper is to review and discuss the recent trends of electrospinning strategies for cartilage tissue engineering, particularly the biomimetic, gradient, and 3D scaffolds, along with future prospects of potential clinical applications.

Fabrication of honeycomb-structured poly(ethylene glycol)-block-poly(lactic acid) porous films and biomedical applications for cell growth

Energy Technology Data Exchange (ETDEWEB)

Yao, Bingjian [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250199 (China); College of chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Normal University, Jinan 250014 (China); Zhu, Qingzeng, E-mail: qzzhu@sdu.edu.cn [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250199 (China); Yao, Linli [Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, 250012 Jinan (China); Hao, Jingcheng [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250199 (China)

2015-03-30

Graphical abstract: - Highlights: • Honeycomb-structured PEG-PLA porous films were fabricated. • The organization of pores depends on molecular weight ratio of PEG-to-PLA block. • The pores in the film were internally decorated with a layer of PEG. • The honeycomb-structured PEG-PLA film was suitable as a substrate for cell growth. - Abstract: A series of poly(ethylene glycol)-block-poly(lactic acid) (PEG-PLA) copolymers with a hydrophobic PLA block of different molecular weights and a fixed length hydrophilic PEG were synthesized successfully and characterized. These amphiphilic block copolymers were used to fabricate honeycomb-structured porous films using the breath figure (BF) templating technique. The surface topology and composition of the highly ordered pattern film were further characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fluorescence microscopy. The results indicated that the PEG-to-PLA block molecular weight ratio influenced the BF film surface topology. The film with the best ordered pores was obtained with a PEG-to-PLA ratio of 2.0 × 10{sup 3}:3.0 × 10{sup 4}. The self-organization of the hydrophilic PEG chains within the pores was confirmed by XPS and fluorescence labeled PEG. A model is proposed to elucidate the stabilization process of the amphiphilic PEG-PLA aggregated architecture on the water droplet-based templates. In addition, GFP-U87 cell viability has been investigated by MTS test and the cell morphology on the honeycomb-structured PEG-PLA porous film has been evaluated using phase-contrast microscope. This porous film is shown to be suitable as a matrix for cell growth.

Fabrication of honeycomb-structured poly(ethylene glycol)-block-poly(lactic acid) porous films and biomedical applications for cell growth

International Nuclear Information System (INIS)

Yao, Bingjian; Zhu, Qingzeng; Yao, Linli; Hao, Jingcheng

2015-01-01

Graphical abstract: - Highlights: • Honeycomb-structured PEG-PLA porous films were fabricated. • The organization of pores depends on molecular weight ratio of PEG-to-PLA block. • The pores in the film were internally decorated with a layer of PEG. • The honeycomb-structured PEG-PLA film was suitable as a substrate for cell growth. - Abstract: A series of poly(ethylene glycol)-block-poly(lactic acid) (PEG-PLA) copolymers with a hydrophobic PLA block of different molecular weights and a fixed length hydrophilic PEG were synthesized successfully and characterized. These amphiphilic block copolymers were used to fabricate honeycomb-structured porous films using the breath figure (BF) templating technique. The surface topology and composition of the highly ordered pattern film were further characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fluorescence microscopy. The results indicated that the PEG-to-PLA block molecular weight ratio influenced the BF film surface topology. The film with the best ordered pores was obtained with a PEG-to-PLA ratio of 2.0 × 10 3 :3.0 × 10 4 . The self-organization of the hydrophilic PEG chains within the pores was confirmed by XPS and fluorescence labeled PEG. A model is proposed to elucidate the stabilization process of the amphiphilic PEG-PLA aggregated architecture on the water droplet-based templates. In addition, GFP-U87 cell viability has been investigated by MTS test and the cell morphology on the honeycomb-structured PEG-PLA porous film has been evaluated using phase-contrast microscope. This porous film is shown to be suitable as a matrix for cell growth

Porous niobium coatings fabricated with selective laser melting on titanium substrates: Preparation, characterization, and cell behavior.

Science.gov (United States)

Zhang, Sheng; Cheng, Xian; Yao, Yao; Wei, Yehui; Han, Changjun; Shi, Yusheng; Wei, Qingsong; Zhang, Zhen

2015-08-01

Nb, an expensive and refractory element with good wear resistance and biocompatibility, is gaining more attention as a new metallic biomaterial. However, the high price of the raw material, as well as the high manufacturing costs because of Nb's strong oxygen affinity and high melting point have limited the widespread use of Nb and its compounds. To overcome these disadvantages, porous Nb coatings of various thicknesses were fabricated on Ti substrate via selective laser melting (SLM), which is a 3D printing technique that uses computer-controlled high-power laser to melt the metal. The morphology and microstructure of the porous Nb coatings, which had pores ranging from 15 to 50 μm in size, were characterized with scanning electron microscopy (SEM). The average hardness of the coating, which was measured with the linear intercept method, was 392±37 HV. In vitro tests of the porous Nb coating which was monitored with SEM, immunofluorescence, and CCK-8 counts of cells, exhibited excellent cell morphology, attachment, and growth. The simulated body fluid test also proved the bioactivity of the Nb coating. Therefore, these new porous Nb coatings could potentially be used for enhanced early biological fixation to bone tissue. In addition, this study has shown that SLM technique could be used to fabricate coatings with individually tailored shapes and/or porosities from group IVB and VB biomedical metals and their alloys on stainless steel, Co-Cr, and other traditional biomedical materials without wasting raw materials. Copyright © 2015 Elsevier B.V. All rights reserved.

The Influence of Electrophoretic Deposition for Fabricating Dye-Sensitized Solar Cell

Directory of Open Access Journals (Sweden)

Jung-Chuan Chou

2014-01-01

Full Text Available Titanium dioxide (TiO2 film was deposited on fluorine-doped tin oxide (FTO glass substrate by electrophoretic deposition method (EPD. TiO2 films were prepared with different I2 dosages, electric field intensities and deposition time (D.T., electrophotic deposition times. By different I2 dosages, electric field intensities, deposition time, electrophotic deposition times fabricated TiO2 films and compared photoelectric characteristics of TiO2 films to find optimal parameters which were the highest photovoltaic conversion efficiency. And use electrochemical impedance spectroscopy (EIS to measure the Nyquist plots under different conditions and analyze the impendence of dye-sensitized solar cells at the internal heterojunction. According to the experimental results, the I2 dosage was 0.025 g which obtained the optimal characteristic parameters. Thickness of TiO2 film was 10.6 μm, the open-circuit voltage (Voc was 0.77 V, the short-circuit current density (Jsc was 7.20 mA/cm2, the fill factor (F.F. was 53.41%, and photovoltaic conversion efficiency (η was 2.96%.

Fabrication of dye-sensitized solar cells with multilayer photoanodes ...

Indian Academy of Sciences (India)

This could show an increase of about 30% in the efficiency compared to the similar ... fabrication, rather than high-energy conversion efficiency ... the photon management, i.e., the increase of the light har- ..... were carried out in −0.8 V in dark.

Subclassification of newly diagnosed glioblastomas through an immunohistochemical approach.

Directory of Open Access Journals (Sweden)

Siobhan Conroy

Full Text Available Molecular signatures in Glioblastoma (GBM have been described that correlate with clinical outcome and response to therapy. The Proneural (PN and Mesenchymal (MES signatures have been identified most consistently, but others including Classical (CLAS have also been reported. The molecular signatures have been detected by array techniques at RNA and DNA level, but these methods are costly and cannot take into account individual contributions of different cells within a tumor. Therefore, the aim of this study was to investigate whether subclasses of newly diagnosed GBMs could be assessed and assigned by application of standard pathology laboratory procedures. 123 newly diagnosed GBMs were analyzed for the tumor cell expression of 23 pre-identified proteins and EGFR amplification, together allowing for the subclassification of 65% of the tumors. Immunohistochemistry (IHC-based profiling was found to be analogous to transcription-based profiling using a 9-gene transcriptional signature for PN and MES subclasses. Based on these data a novel, minimal IHC-based scheme for subclass assignment for GBMs is proposed. Positive staining for IDH1R132H can be used for PN subclass assignment, high EGFR expression for the CLAS subtype and a combined high expression of PTEN, VIM and/or YKL40 for the MES subclass. The application of the proposed scheme was evaluated in an independent tumor set, which resulted in similar subclass assignment rates as those observed in the training set. The IHC-based subclassification scheme proposed in this study therefore could provide very useful in future studies for stratification of individual patient samples.

Fabrication of non-hexagonal close packed colloidal array on a substrate by transfer

Science.gov (United States)

Banik, Meneka; Mukherjee, Rabibrata

Self-organized colloidal arrays find application in fabrication of solar cells with advanced light management strategies. We report a simple spincoating based approach for fabricating two dimensional colloidal crystals with hexagonal and non-hexagonal close packed assembly on flat and nanopatterned substrates. The non-HCP arrays were fabricated by spin coating the particles onto soft lithographically fabricated substrates. The substrate patterns impose directionality to the particles by confining them within the grooves. We have developed a technique by which the HCP and non-HCP arrays can be transferred to any surface. For this purpose the colloidal arrays were fabricated on a UV degradable PMMA layer, resulting in transfer of the particles on UV exposure. This allows the colloidal structures to be transported across substrates irrespective of their surface energy, wettability or morphology. Since the particles are transferred without exposing it to any kind of chemical or thermal environment, it can be utilized for placing particles on top of thin film solar cells for improving their absorption efficiency.

A novel 2D silicon nano-mold fabrication technique for linear nanochannels over a 4 inch diameter substrate

Science.gov (United States)

Yin, Zhifu; Qi, Liping; Zou, Helin; Sun, Lei

2016-01-01

A novel low-cost 2D silicon nano-mold fabrication technique was developed based on Cu inclined-deposition and Ar+ (argon ion) etching. With this technique, sub-100 nm 2D (two dimensional) nano-channels can be etched economically over the whole area of a 4 inch n-type  silicon wafer. The fabricating process consists of only 4 steps, UV (Ultraviolet) lithography, inclined Cu deposition, Ar+ sputter etching, and photoresist & Cu removing. During this nano-mold fabrication process, we investigated the influence of the deposition angle on the width of the nano-channels and the effect of Ar+ etching time on their depth. Post-etching measurements showed the accuracy of the nanochannels over the whole area: the variation in width is 10%, in depth it is 11%. However, post-etching measurements also showed the accuracy of the nanochannels between chips: the variation in width is 2%, in depth it is 5%. With this newly developed technology, low-cost and large scale 2D nano-molds can be fabricated, which allows commercial manufacturing of nano-components over large areas. PMID:26752559

Metallizing porous scaffolds as an alternative fabrication method for solid oxide fuel cell anodes

Science.gov (United States)

Ruiz-Trejo, Enrique; Atkinson, Alan; Brandon, Nigel P.

2015-04-01

A combination of electroless and electrolytic techniques is used to incorporate nickel into a porous Ce0.9Gd0.1O1.90 scaffold. First a porous backbone was screen printed into a YSZ electrolyte using an ink that contains sacrificial pore formers. Once sintered, the scaffold was coated with silver using Tollens' reaction followed by electrodeposition of nickel in a Watts bath. At high temperatures the silver forms droplets enabling direct contact between the gadolinia-doped ceria and nickel. Using impedance spectroscopy analysis in a symmetrical cell a total area specific resistance of 1 Ωcm2 at 700 °C in 97% H2 with 3% H2O was found, indicating the potential of this fabrication method for scaling up.

Immunoparesis in newly diagnosed Multiple Myeloma patients

DEFF Research Database (Denmark)

Sorrig, Rasmus; Klausen, Tobias W.; Salomo, Morten

2017-01-01

Immunoparesis (hypogammaglobulinemia) is associated to an unfavorable prognosis in newly diagnosed Multiple myeloma (MM) patients. However, this finding has not been validated in an unselected population-based cohort. We analyzed 2558 newly diagnosed MM patients in the Danish Multiple Myeloma...

Fabricated Elastin.

Science.gov (United States)

Yeo, Giselle C; Aghaei-Ghareh-Bolagh, Behnaz; Brackenreg, Edwin P; Hiob, Matti A; Lee, Pearl; Weiss, Anthony S

2015-11-18

The mechanical stability, elasticity, inherent bioactivity, and self-assembly properties of elastin make it a highly attractive candidate for the fabrication of versatile biomaterials. The ability to engineer specific peptide sequences derived from elastin allows the precise control of these physicochemical and organizational characteristics, and further broadens the diversity of elastin-based applications. Elastin and elastin-like peptides can also be modified or blended with other natural or synthetic moieties, including peptides, proteins, polysaccharides, and polymers, to augment existing capabilities or confer additional architectural and biofunctional features to compositionally pure materials. Elastin and elastin-based composites have been subjected to diverse fabrication processes, including heating, electrospinning, wet spinning, solvent casting, freeze-drying, and cross-linking, for the manufacture of particles, fibers, gels, tubes, sheets and films. The resulting materials can be tailored to possess specific strength, elasticity, morphology, topography, porosity, wettability, surface charge, and bioactivity. This extraordinary tunability of elastin-based constructs enables their use in a range of biomedical and tissue engineering applications such as targeted drug delivery, cell encapsulation, vascular repair, nerve regeneration, wound healing, and dermal, cartilage, bone, and dental replacement. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabrication of White Light-emitting Electrochemical Cells with Stable Emission from Exciplexes.

Science.gov (United States)

Uchida, Soichi; Takizawa, Daisuke; Ikeda, Satoru; Takeuchi, Hironori; Nishimura, Suzushi; Nishide, Hiroyuki; Nishikitani, Yoshinori

2016-11-15

The authors present an approach for fabricating stable white light emission from polymer light-emitting electrochemical cells (PLECs) having an active layer which consists of blue-fluorescent poly(9,9-di-n-dodecylfluorenyl-2,7-diyl) (PFD) and π-conjugated triphenylamine molecules. This white light emission originates from exciplexes formed between PFD and amines in electronically excited states. A device containing PFD, 4,4',4''-tris[2-naphthyl(phenyl)amino]triphenylamine (2-TNATA), Poly(ethylene oxide) and K2CF3SO3 showed white light emission with Commission internationale de l'éclairage (CIE) coordinates of (0.33, 0.43) and a Color Rendering Index (CRI) of Ra = 73 at an applied voltage of 3.5 V. Constant voltage measurements showed that the CIE coordinates of (0.27, 0.37), Ra of 67, and the emission color observed immediately after application of a voltage of 5 V were nearly unchanged and stable after 300 sec.

Influence of cell shape on mechanical properties of Ti-6Al-4V meshes fabricated by electron beam melting method.

Science.gov (United States)

Li, S J; Xu, Q S; Wang, Z; Hou, W T; Hao, Y L; Yang, R; Murr, L E

2014-10-01

Ti-6Al-4V reticulated meshes with different elements (cubic, G7 and rhombic dodecahedron) in Materialise software were fabricated by additive manufacturing using the electron beam melting (EBM) method, and the effects of cell shape on the mechanical properties of these samples were studied. The results showed that these cellular structures with porosities of 88-58% had compressive strength and elastic modulus in the range 10-300MPa and 0.5-15GPa, respectively. The compressive strength and deformation behavior of these meshes were determined by the coupling of the buckling and bending deformation of struts. Meshes that were dominated by buckling deformation showed relatively high collapse strength and were prone to exhibit brittle characteristics in their stress-strain curves. For meshes dominated by bending deformation, the elastic deformation corresponded well to the Gibson-Ashby model. By enhancing the effect of bending deformation, the stress-strain curve characteristics can change from brittle to ductile (the smooth plateau area). Therefore, Ti-6Al-4V cellular solids with high strength, low modulus and desirable deformation behavior could be fabricated through the cell shape design using the EBM technique. Copyright © 2014 Acta Materialia Inc. All rights reserved.

Design, Fabrication and Characterization of an In Silico Cell Physiology lab for Bio Sensing Applications

International Nuclear Information System (INIS)

Haque, A ul; Rokkam, M; De Carlo, A R; Wereley, S T; Wells, H W; McLamb, W T; Roux, S J; Irazoqui, P P; Porterfield, D M

2006-01-01

In this paper, we report the design, fabrication and characterization of an In Silico cell physiology biochip for measuring Ca 2+ ion concentrations and currents around single cells. This device has been designed around specific science objectives of measuring real time multidimensional calcium flux patterns around sixteen Ceratopteris richardii fern spores in microgravity flight experiments and ground studies. The sixteen microfluidic cell holding pores are 150 by 150 μm each and have 4 Ag/AgCl electrodes leading into them. An SU-8 structural layer is used for insulation and packaging purposes. The In Silico cell physiology lab is wire bonded on to a custom PCB for easy interface with a state of the art data acquisition system. The electrodes are coated with a Ca 2+ ion selective membrane based on ETH-5234 ionophore and operated against an Ag/AgCl reference electrode. Initial characterization results have shown Nernst slopes of 30mv/decade that were stable over a number of measurement cycles. While this work is focused on technology to enable basic research on the Ceratopteris richardii spores, we anticipate that this type of cell physiology lab-on-a-chip will be broadly applied in biomedical and pharmacological research by making minor modifications to the electrode material and the measurement technique. Future applications include detection of glucose, hormones such as plant auxin, as well as multiple analyte detection on the same chip

Fabrication and characterization of rubidium/formamidinium-incorporated methylammonium-lead-halide perovskite solar cells

Science.gov (United States)

Kato, Masataka; Suzuki, Atsushi; Ohishi, Yuya; Tanaka, Hiroki; Oku, Takeo

2018-01-01

Fabrication and characterization of perovskite solar cells using mesoporous TiO2 as an electron transporting layer and 2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene as a hole-transporting layer were performed for improving the photovoltaic performance. Additive effects of formamidinium (FA), rubidium (Rb), chlorine (Cl) and bromine (Br) into the methylammonium-lead-halide perovskite crystal on the photovoltaic properties and microstructures were investigated. The photovoltaic parameters of short-circuit current density, conversion efficiency, the surface morphology and domain in the perovskite crystal were characterized. The slight addition of FACl and RbBr to the CH3NH3PbI3 crystal provided homogeneous microstructures with the dispersed crystal domains, which improved the photovoltaic performance. The excess addition of Cl to the perovskite crystal caused nanorod-like crystals, which degraded the photovoltaic performance.

Optimizing The DSSC Fabrication Process Using Lean Six Sigma

Science.gov (United States)

Fauss, Brian

Alternative energy technologies must become more cost effective to achieve grid parity with fossil fuels. Dye sensitized solar cells (DSSCs) are an innovative third generation photovoltaic technology, which is demonstrating tremendous potential to become a revolutionary technology due to recent breakthroughs in cost of fabrication. The study here focused on quality improvement measures undertaken to improve fabrication of DSSCs and enhance process efficiency and effectiveness. Several quality improvement methods were implemented to optimize the seven step individual DSSC fabrication processes. Lean Manufacturing's 5S method successfully increased efficiency in all of the processes. Six Sigma's DMAIC methodology was used to identify and eliminate each of the root causes of defects in the critical titanium dioxide deposition process. These optimizations resulted with the following significant improvements in the production process: 1. fabrication time of the DSSCs was reduced by 54 %; 2. fabrication procedures were improved to the extent that all critical defects in the process were eliminated; 3. the quantity of functioning DSSCs fabricated was increased from 17 % to 90 %.

A novel bonding method for large scale poly(methyl methacrylate) micro- and nanofluidic chip fabrication

Science.gov (United States)

Qu, Xingtian; Li, Jinlai; Yin, Zhifu

2018-04-01

Micro- and nanofluidic chips are becoming increasing significance for biological and medical applications. Future advances in micro- and nanofluidics and its utilization in commercial applications depend on the development and fabrication of low cost and high fidelity large scale plastic micro- and nanofluidic chips. However, the majority of the present fabrication methods suffer from a low bonding rate of the chip during thermal bonding process due to air trapping between the substrate and the cover plate. In the present work, a novel bonding technique based on Ar plasma and water treatment was proposed to fully bond the large scale micro- and nanofluidic chips. The influence of Ar plasma parameters on the water contact angle and the effect of bonding conditions on the bonding rate and the bonding strength of the chip were studied. The fluorescence tests demonstrate that the 5 × 5 cm2 poly(methyl methacrylate) chip with 180 nm wide and 180 nm deep nanochannels can be fabricated without any block and leakage by our newly developed method.

Fabrication and properties of meso-macroporous electrodes screen-printed from mesoporous titania nanoparticles for dye-sensitized solar cells

International Nuclear Information System (INIS)

Ma Liang; Liu Min; Peng Tianyou; Fan Ke; Lu Lanlan; Dai Ke

2009-01-01

A meso-macroporous TiO 2 film electrode was fabricated by using mesoporous TiO 2 (m-TiO 2 ) nanoparticles through a screen-printing technique in order to efficiently control the main fabrication step of dye-sensitized solar cells (DSSCs). The qualities of the screen-printed m-TiO 2 films were characterized by means of spectroscopy, electron microscopy, nitrogen adsorption-desorption and photoelectrochemical measurements. Under the optimal paste composition and printing conditions, the DSSC based on the meso-macroporous m-TiO 2 film electrode exhibits an energy conversion efficiency of 4.14%, which is improved by 1.70% in comparison with DSSC made with commercially available nonporous TiO 2 nanoparticles (P25, Degussa) electrode printed with a similar paste composition. The meso-macroporous structure within the m-TiO 2 film is of great benefit to the dye adsorption, light absorption and the electrolyte transportation, and then to the improvement of the overall energy conversion efficiency of DSSC.

Modified wound dressing with phyto-nanostructured coating to prevent staphylococcal and pseudomonal biofilm development

OpenAIRE

Anghel, Ion; Holban, Alina Maria; Grumezescu, Alexandru Mihai; Andronescu, Ecaterina; Ficai, Anton; Anghel, Alina Georgiana; Maganu, Maria; Laz?r, Veronica; Chifiriuc, Mariana Carmen

2012-01-01

This paper reports a newly fabricated nanophyto-modified wound dressing with microbicidal and anti-adherence properties. Nanofluid-based magnetite doped with eugenol or limonene was used to fabricate modified wound dressings. Nanostructure coated materials were characterized by TEM, XRD, and FT-IR. For the quantitative measurement of biofilm-embedded microbial cells, a culture-based method for viable cell count was used. The optimized textile dressing samples proved to be more resistant to st...

Xylan polysaccharides fabricated into nanofibrous substrate for myocardial infarction

International Nuclear Information System (INIS)

Venugopal, J.; Rajeswari, R.; Shayanti, M.; Sridhar, R.; Sundarrajan, S.; Balamurugan, R.; Ramakrishna, S.

2013-01-01

Myocardial infarction, a main cause of heart failure, leads to loss of cardiac tissue impairment of left ventricular function. Repair of diseased myocardium with in vitro engineered cardiac muscle patch/injectable biopolymers with cells may become a viable option for myocardial infarction. We attempted to solve these problems by in vitro study by selecting a plant based polysaccharides beech wood Xylan for the normal functioning of infarcted myocardium. The present study fabricated Xylan based nanofibrous scaffolds cross-linked with glutaraldehyde (Glu) vapors for 24 h, 48 h and 1% Glu blended fibers for the culture of neonatal rat cardiac cells for myocardial infarction. These nanofibers were characterized by SEM, FT-IR, tensile testing and cell culture studies for the normal expression of cardiac proteins. The observed results showed that the Xylan/polyvinyl alcohol (PVA) 24 h Glu vapor cross-linked nanofibers (427 nm) having mechanical strength of 2.43 MPa and Young modulus of 3.74 MPa are suitable for the culture of cardiac cells. Cardiac cells proliferation increased only by 11% in Xylan/PVA 24 h Glu cross-linked nanofibers compared to control tissue culture plate (TCP). The normal cardiac cell morphology was observed in 24 h cross-linked Xylan/PVA nanofibers but 48 h cross-linked fibers cell morphology was changed to flattened and elongated on the fibrous surfaces. Confocal analysis for cardiac expression proteins actinin, connexin 43 was observed normally in 24 h Glu cross-linked nanofibers compared to all other nanofibrous scaffolds. The fabricated Xylan/PVA nanofibrous scaffold may have good potential for the normal functioning of infarcted myocardium. - Highlights: ► Fabrication of polysaccharides Xylan/PVA nanofibers for cardiac tissue engineering ► Nanofibers characterized by SEM, FT-IR, tensile testing and cell culture studies ► Isolation of cardiac cells and cultured on Xylan/PVA nanofibrous scaffolds ► Cultured cells on 24 h Glu cross

Xylan polysaccharides fabricated into nanofibrous substrate for myocardial infarction

Energy Technology Data Exchange (ETDEWEB)

Venugopal, J., E-mail: nnijrv@nus.edu.sg; Rajeswari, R.; Shayanti, M.; Sridhar, R.; Sundarrajan, S.; Balamurugan, R.; Ramakrishna, S.

2013-04-01

Myocardial infarction, a main cause of heart failure, leads to loss of cardiac tissue impairment of left ventricular function. Repair of diseased myocardium with in vitro engineered cardiac muscle patch/injectable biopolymers with cells may become a viable option for myocardial infarction. We attempted to solve these problems by in vitro study by selecting a plant based polysaccharides beech wood Xylan for the normal functioning of infarcted myocardium. The present study fabricated Xylan based nanofibrous scaffolds cross-linked with glutaraldehyde (Glu) vapors for 24 h, 48 h and 1% Glu blended fibers for the culture of neonatal rat cardiac cells for myocardial infarction. These nanofibers were characterized by SEM, FT-IR, tensile testing and cell culture studies for the normal expression of cardiac proteins. The observed results showed that the Xylan/polyvinyl alcohol (PVA) 24 h Glu vapor cross-linked nanofibers (427 nm) having mechanical strength of 2.43 MPa and Young modulus of 3.74 MPa are suitable for the culture of cardiac cells. Cardiac cells proliferation increased only by 11% in Xylan/PVA 24 h Glu cross-linked nanofibers compared to control tissue culture plate (TCP). The normal cardiac cell morphology was observed in 24 h cross-linked Xylan/PVA nanofibers but 48 h cross-linked fibers cell morphology was changed to flattened and elongated on the fibrous surfaces. Confocal analysis for cardiac expression proteins actinin, connexin 43 was observed normally in 24 h Glu cross-linked nanofibers compared to all other nanofibrous scaffolds. The fabricated Xylan/PVA nanofibrous scaffold may have good potential for the normal functioning of infarcted myocardium. - Highlights: ► Fabrication of polysaccharides Xylan/PVA nanofibers for cardiac tissue engineering ► Nanofibers characterized by SEM, FT-IR, tensile testing and cell culture studies ► Isolation of cardiac cells and cultured on Xylan/PVA nanofibrous scaffolds ► Cultured cells on 24 h Glu cross

Fabrication and characterization of injection molded multi level nano and microfluidic systems

DEFF Research Database (Denmark)

Matteucci, Marco; Christiansen, Thomas Lehrmann; Tanzi, Simone

2013-01-01

We here present a method for fabrication of multi-level all-polymer chips by means of silicon dry etching, electroplating and injection molding. This method was used for successful fabrication of microfluidic chips for applications in the fields of electrochemistry, cell trapping and DNA elongati...

Fabrication of Spin-Transfer Nano-Oscillator by Colloidal Lithography

Directory of Open Access Journals (Sweden)

Bin Fang

2015-01-01

Full Text Available We fabricate nanoscale spin-transfer oscillators (STOs by utilizing colloidal nanoparticles as a lithographic mask. By this approach, high quality STO devices can be fabricated, and as an example the fabricated STO devices using MgO magnetic tunnel junction as the basic cell exhibit current-induced microwave emission with a large frequency tunability of 0.22 GHz/mA. Compared to the conventional approaches that involve a step of defining nanoscale elements by means of electron beam lithography, which is not readily available for many groups, our strategy for STO fabrication does not require the sophisticated equipment (~ million dollars per unit and expensive lithography resist, while being cost-effective and easy to use in laboratory level. This will accelerate efforts to implement STO into on-chip integrated high-radio frequency applications.

Novel elastomeric fibrous networks produced from poly(xylitol sebacate)2:5 by core/shell electrospinning: fabrication and mechanical properties.

Science.gov (United States)

Li, Yuan; Thouas, George A; Chen, Qizhi

2014-12-01

Fabrication of nonlinear elastic materials that resemble biological tissues remains a challenge in biomaterials research. Here, a new fabrication protocol to produce elastomeric fibrous scaffolds was established, using the core/shell electrospinning technique. A prepolymer of poly(xylitol sebacate) with a 2:5mol ratio of xylitol:sebacic acid (PXS2:5) was first formulated, then co-electrospun with polyvinyl alcohol (PVA - 95,000Mw). After cross-linking of core polymer PXS2:5, the PVA shells were rinsed off in water, leaving a porous elastomeric network of PXS2:5 fibres. Under aqueous conditions, the PXS2:5 fibrous scaffolds exhibited stable, nonlinear J-shaped stress-strain curves, with large average rupture elongation (76%) and Young׳s modulus (~1.0MPa), which were in the range of muscle tissue. Rupture elongation of PXS2:5 was also much higher when electrospun, compared to 2D solid sheets (45%). In direct contact with cell monolayers under physiological conditions, PXS2:5 scaffolds were as biocompatible as those made of poly-l-lactic acid (PLLA), with improvements over culture medium alone. In conclusion, the newly developed porous PXS2:5 scaffolds show tissue-like mechanical properties and excellent biocompatibility, making them very promising for bioengineering of soft tissues and organs. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Low-temperature-fabricated ZnO, AZO, and SnO{sub 2} nanoparticle-based dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Kim, Hong Hee; Park, Cheolmin; Choi, Wonkook; Cho, Sungjae; Moon, Byungjoon; Son, Dongick [Korea Institute of Science and Technology, Seoul (Korea, Republic of); Yonsei University, Seoul (Korea, Republic of)

2014-11-15

The authors investigated the microstructural and the electrical properties of ZnO, AZO, and SnO{sub 2} based dye-sensitized solar cells (DSSCs) fabricated using a low-temperature-processed (200 .deg. C) dyesensitized ZnO, AZO, and SnO{sub 2} nanoparticle thin film and a Pt catalyst deposited on ITO/glass by RF magnetron sputtering. A hydropolymer containing PEG (poly ethylene glycol) and PEO (poly ethylene oxide) is used to make uniformly-distributed ZnO, AZO, and SnO{sub 2} nanoparticle layer which forms a nano porous ZnO, AZO, and SnO{sub 2} network after heat treatment. The layer is then dye sensitized and sandwiched between two electrodes in an electrolyte to make a DSSC device. The highest measured parameters, the short-circuit current density (J{sub sc}), the open circuit potential (V{sub oc}), the fill factor (FF), and power conversion efficiency (η), of the DSSC fabricated wander optimized conditions were observed to be 5.10 mA/cm{sup 2}, 0.61 V, 0.46, and 1.43%, respectively.

Partition efficiencies of newly fabricated universal high-speed counter-current chromatograph for separation of two different types of sugar derivatives with organic-aqueous two-phase solvent systems

Science.gov (United States)

Shinomiya, Kazufusa; Sato, Kazuki; Yoshida, Kazunori; Tokura, Koji; Maruyama, Hiroshi; Yanagidaira, Kazuhiro; Ito, Yoichiro

2013-01-01

Universal high-speed counter-current chromatograph (HSCCC) was newly designed and fabricated in our laboratory. It holds a set of four column holders symmetrically around the rotary frame at a distance of 11.2 cm from the central axis. By engaging the stationary gear on the central axis of the centrifuge to the planetary gears on the column holder shaft through a set of idle gears, two pairs of diagonally located column holders simultaneously rotate about their own axes in the opposite directions: one forward (type-J planetary motion) and the other backward (type-I planetary motion) each synchronously with the revolution. Using the eccentric coil assembly, partition efficiencies produced by these two planetary motions were compared on the separation of two different types of sugar derivatives (4-methylumbelliferyl and 5-bromo-4-chloro-3-indoxyl sugar derivatives) using organic-aqueous two-phase solvent systems composed of n-hexane/ethyl acetate/1-butanol/methanol/water and aqueous 0.1 M sodium tetraborate, respectively. With lower phase mobile, better peak resolution was obtained by the type-J forward rotation for both samples probably due to higher retention of the stationary phase. With upper phase mobile, however, similar peak resolutions were obtained between these two planetary motions for both sugar derivatives. The overall results indicate that the present universal HSCCC is useful for counter-current chromatographic separation since each planetary motion has its specific applications: e.g., vortex CCC by the type-I planetary motion and HSCCC by the type-J planetary motion both for separation of various natural and synthetic products. PMID:24267319

Effects of Garlic Oil on the Migration of Neutrophil-Like Cell Studied by Using a Chemotactic Gradient Labchip

Directory of Open Access Journals (Sweden)

Po-Chen Shih

2010-01-01

Full Text Available We have designed and fabricated a novel chemotactic gradient Labchip for studying cell migration quantitatively. Owing to the great potential of garlic and its preparations in developing antiinflammatory drugs, the aim of the present study is to investigate the effect of garlic oil on the locomotion of a neutrophil-like cell by measuring the dynamic features of cell migration including migration direction, average migration speed, chemotactic index (CI, and motility index (MI with the newly designed Labchip. We found that garlic oil treatment lowered the values of CI and MI and reduced the average speed of cell migration from 13 to 8 μm/min. The results indicate that garlic oil is a potential inhibitor for neutrophil-like cell migration and chemotactic responsiveness. By comparing with the effects of nocodazole and cytochalasin B, we also suggest that the antiinflammatory activity exhibited by garlic oil was mainly through inhibiting the assembly-disassembly processes of the cytoskeleton.

Fuel fabrication and post-irradiation examination

Energy Technology Data Exchange (ETDEWEB)

Venter, P J; Aspeling, J C [Atomic Energy Corporation of South Africa Ltd., Pretoria (South Africa)

1990-06-01

This paper provides an overview of the A/c's Bevan and Eldopar facilities for the fabrication of nuclear fuel. It also describes the sophisticated Hot Cell Complex, which is capable of accommodating pressurised water reactor fuel and various other irradiated samples. Some interesting problems and their solutions are discussed. (author)

Fuel fabrication and post-irradiation examination

International Nuclear Information System (INIS)

Venter, P.J.; Aspeling, J.C.

1990-01-01

This paper provides an overview of the A/c's Bevan and Eldopar facilities for the fabrication of nuclear fuel. It also describes the sophisticated Hot Cell Complex, which is capable of accommodating pressurised water reactor fuel and various other irradiated samples. Some interesting problems and their solutions are discussed. (author)

Overcoming Short-Circuit in Lead-Free CH3NH3SnI3 Perovskite Solar Cells via Kinetically Controlled Gas-Solid Reaction Film Fabrication Process.

Science.gov (United States)

Yokoyama, Takamichi; Cao, Duyen H; Stoumpos, Constantinos C; Song, Tze-Bin; Sato, Yoshiharu; Aramaki, Shinji; Kanatzidis, Mercouri G

2016-03-03

The development of Sn-based perovskite solar cells has been challenging because devices often show short-circuit behavior due to poor morphologies and undesired electrical properties of the thin films. A low-temperature vapor-assisted solution process (LT-VASP) has been employed as a novel kinetically controlled gas-solid reaction film fabrication method to prepare lead-free CH3NH3SnI3 thin films. We show that the solid SnI2 substrate temperature is the key parameter in achieving perovskite films with high surface coverage and excellent uniformity. The resulting high-quality CH3NH3SnI3 films allow the successful fabrication of solar cells with drastically improved reproducibility, reaching an efficiency of 1.86%. Furthermore, our Kelvin probe studies show the VASP films have a doping level lower than that of films prepared from the conventional one-step method, effectively lowering the film conductivity. Above all, with (LT)-VASP, the short-circuit behavior often obtained from the conventional one-step-fabricated Sn-based perovskite devices has been overcome. This study facilitates the path to more successful Sn-perovskite photovoltaic research.

Fabrication and tests of anode supported solid oxide fuel cell; Fabricacao e testes de celula a combustivel de oxido solido suportada no anodo

Energy Technology Data Exchange (ETDEWEB)

Florio, D.Z. de [UNESP, Araraquara, SP (Brazil)], e-mail: dzflorio@ipen.br; Fonseca, F.C.; Franca, Y.V.; Muccillo, E.N.S.; Muccillo, R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Berton, M.A.C.; Garcia, C.M. [LACTEC - Instituto de Tecnologia para o Desenvolvimento, Curitiba, PR (Brazil)

2006-07-01

A laboratory setup was designed and put into operation for the development of solid oxide fuel cells (SOFCs). Ceramic single cells were fabricated by low-cost methods, and emphasis was given to the use of ready available raw materials. The whole project consisted of the preparation of the component materials - anode, cathode, and electrolyte - and the buildup of a hydrogen leaking-free sample chamber with platinum leads and current collectors for measuring the electrochemical properties of single SOFCs. Anode-supported single SOFCs of the type (ZrO{sub 2}:Y{sub 2}O{sub 3} + NiO) anode / (ZrO{sub 2}:Y{sub 2}O{sub 3}) electrolyte / (La{sub 0.65}Sr{sub 0.35}MnO{sub 3} + ZrO{sub 2}:Y{sub 2}O{sub 3}) cathode have been prepared and tested at 700 deg C and 800 deg C after in situ H{sub 2} anode reduction. The main results show that the slurry coating method resulted in single-cells with good reproducibility and reasonable performance, suggesting that this method can be considered for fabrication of SOFCs. (author)

An engineered cell-imprinted substrate directs osteogenic differentiation in stem cells

DEFF Research Database (Denmark)

Kamguyan, Khorshid; Katbab, Ali Asghar; Mahmoudi, Morteza

2018-01-01

A cell-imprinted poly(dimethylsiloxane)/hydroxyapatite nanocomposite substrate was fabricated to engage topographical, mechanical, and chemical signals to stimulate and boost stem cell osteogenic differentiation. The physicochemical properties of the fabricated substrates, with nanoscale resolution...

Strategies for the fabrication of porous platinum electrodes

Energy Technology Data Exchange (ETDEWEB)

Kloke, Arne; Stetten, Felix von; Kerzenmacher, Sven [Laboratory for MEMS Applications, Department of Microsystems Engineering-IMTEK, University of Freiburg, Freiburg (Germany); Zengerle, Roland [Laboratory for MEMS Applications, Department of Microsystems Engineering-IMTEK, University of Freiburg, Freiburg (Germany); BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-Universitaet Freiburg (Germany)

2011-11-16

Porous platinum is of high technological importance due to its various applications in fuel cells, sensors, stimulation electrodes, mechanical actuators and catalysis in general. Based on a discussion of the general principles behind the reduction of platinum salts and corresponding deposition processes this article discusses techniques available for platinum electrode fabrication. The numerous, different strategies available to fabricate platinum electrodes are reviewed and discussed in the context of their tuning parameters, strengths and weaknesses. These strategies comprise bottom-up approaches as well as top-down approaches. In bottom-up approaches nanoparticles are synthesized in a first step by chemical, photochemical or sonochemical means followed by an electrode formation step by e.g. thin film technology or network formation to create a contiguous and conducting solid electrode structure. In top-down approaches fabrication starts with an already conductive electrode substrate. Corresponding strategies enable the fabrication of substrate-based electrodes by e.g. electrodeposition or the fabrication of self-supporting electrodes by dealloying. As a further top-down strategy, this review describes methods to decorate porous metals other than platinum with a surface layer of platinum. This way, fabrication methods not performable with platinum can be applied to the fabrication of platinum electrodes with the special benefit of low platinum consumption. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Fabrication of antireflective nanostructures for crystalline silicon solar cells by reactive ion etching

International Nuclear Information System (INIS)

Lin, Hsin-Han; Chen, Wen-Hua; Wang, Chi-Jen; Hong, Franklin Chau-Nan

2013-01-01

In this study we have fabricated large-area (15 × 15 cm 2 ) subwavelength antireflection structure on poly-Si substrates to reduce their solar reflectivity. A reactive ion etching system was used to fabricate nanostructures on the poly-silicon surface. Reactive gases, composed of chlorine (Cl 2 ), sulfur hexafluoride (SF 6 ) and oxygen (O 2 ), were activated to fabricate nanoscale pyramids by RF plasma. The poly-Si substrates were etched in various gas compositions for 6–10 min to form nano-pyramids. The sizes of pyramids were about 200–300 nm in heights and about 100 nm in width. Besides the nanoscale features, the high pyramid density on the poly-Si surface is another important factor to reduce the reflectivity. Low-reflectivity surface was fabricated with reflectivity significantly reduced down to < 2% for photons in a wavelength range of 500–900 nm. - Highlights: ► Large-area (15 × 15 cm 2 ) antireflection structures fabricated on poly-Si substrates ► Si nano-pyramids produced by utilizing self-masked reactive ion etching process ► High density of nanoscale pyramids was formed on the entire substrate surface. ► Surface reflectivity below 2% was achieved in the wavelength range of 500–900 nm

Generational differences among newly licensed registered nurses.

Science.gov (United States)

Keepnews, David M; Brewer, Carol S; Kovner, Christine T; Shin, Juh Hyun

2010-01-01

Responses of 2369 newly licensed registered nurses from 3 generational cohorts-Baby Boomers, Generation X, and Generation Y-were studied to identify differences in their characteristics, work-related experiences, and attitudes. These responses revealed significant differences among generations in: job satisfaction, organizational commitment, work motivation, work-to-family conflict, family-to-work conflict, distributive justice, promotional opportunities, supervisory support, mentor support, procedural justice, and perceptions of local job opportunities. Health organizations and their leaders need to anticipate intergenerational differences among newly licensed nurses and should provide for supportive working environments that recognize those differences. Orientation and residency programs for newly licensed nurses should be tailored to the varying needs of different generations. Future research should focus on evaluating the effectiveness of orientation and residency programs with regard to different generations so that these programs can be tailored to meet the varying needs of newly licensed nurses at the start of their careers. Copyright 2010 Mosby, Inc. All rights reserved.

GABA regulates synaptic integration of newly generated neurons in the adult brain

Science.gov (United States)

Ge, Shaoyu; Goh, Eyleen L. K.; Sailor, Kurt A.; Kitabatake, Yasuji; Ming, Guo-Li; Song, Hongjun

2006-02-01

Adult neurogenesis, the birth and integration of new neurons from adult neural stem cells, is a striking form of structural plasticity and highlights the regenerative capacity of the adult mammalian brain. Accumulating evidence suggests that neuronal activity regulates adult neurogenesis and that new neurons contribute to specific brain functions. The mechanism that regulates the integration of newly generated neurons into the pre-existing functional circuitry in the adult brain is unknown. Here we show that newborn granule cells in the dentate gyrus of the adult hippocampus are tonically activated by ambient GABA (γ-aminobutyric acid) before being sequentially innervated by GABA- and glutamate-mediated synaptic inputs. GABA, the major inhibitory neurotransmitter in the adult brain, initially exerts an excitatory action on newborn neurons owing to their high cytoplasmic chloride ion content. Conversion of GABA-induced depolarization (excitation) into hyperpolarization (inhibition) in newborn neurons leads to marked defects in their synapse formation and dendritic development in vivo. Our study identifies an essential role for GABA in the synaptic integration of newly generated neurons in the adult brain, and suggests an unexpected mechanism for activity-dependent regulation of adult neurogenesis, in which newborn neurons may sense neuronal network activity through tonic and phasic GABA activation.

Establishment of technological basis for fabrication of U-Pu-Zr ternary alloy fuel pins for irradiation tests in Japan

International Nuclear Information System (INIS)

Kikuchi, Hironobu; Iwai, Takashi; Nakajima, Kunihisa; Arai, Yasuo; Nakamura, Kinya; Ogata, Takanari

2011-01-01

A high-purity Ar gas atmosphere glove box accommodating injection casting and sodium-bonding apparatuses was newly installed in the Plutonium Fuel Research Facility of Oarai Research and Development Center, Japan Atomic Energy Agency, in which several nitride and carbide fuel pins were fabricated for irradiation tests. The experiences led to the establishment of the technological basis of the fabrication of U-Pu-Zr alloy fuel pins for the first time in Japan. After the injection casting of the U-Pu-Zr alloy, the metallic fuel pins were fabricated by welding upper and lower end plugs with cladding tubes of ferritic-martensitic steel. Subsequent to the sodium bonding for filling the annular gap region between the U-Pu-Zr alloy and the cladding tube with the melted sodium, the fuel pins for irradiation tests are inspected. This paper shows the apparatuses and the technological basis for the fabrication of U-Pu-Zr alloy fuel pins for the irradiation test planned at the experimental fast test reactor Joyo. (author)

Fabrication of selenization-free superstrate-type CuInS{sub 2} solar cells based on all-spin-coated layers

Energy Technology Data Exchange (ETDEWEB)

Cheshme khavar, Amir Hossein [Department of Chemistry, Tarbiat Modares University, P.O. Box. 14155-4383, Gisha Bridge, Tehran (Iran, Islamic Republic of); Mahjoub, Alireza, E-mail: mahjouba@modares.ac.ir [Department of Chemistry, Tarbiat Modares University, P.O. Box. 14155-4383, Gisha Bridge, Tehran (Iran, Islamic Republic of); Samghabadi, Farnaz Safi [Physics Department, Sharif University of Technology, Tehran, 14588 (Iran, Islamic Republic of); Taghavinia, Nima, E-mail: taghavinia@sharif.edu [Physics Department, Sharif University of Technology, Tehran, 14588 (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran, 14588 (Iran, Islamic Republic of)

2017-01-15

Today manufacturing of high efficiency chalcogenide thin film solar cells is based on high cost vacuum-based deposition processes at high temperature (>500 °C) and in chalcogen -containing atmosphere. In this paper, we introduce a simple vacuum-free and selenization-free, solution processing for fabricating a superstrate-type CuInS{sub 2} (CIS) solar cell. The absorber, buffer and blocking layers were all deposited by spin coating of molecular precursor inks. We demonstrate the deposition of In{sub 2}S{sub 3} buffer layer by sol-gel spin casting for the first time. The rapid sintering process of CIS layer was carried out at 250 °C that is considered a very low temperature in CIGS thin-film technologies. A novel molecular-ink route to deposit In{sub 2}S{sub 3} type buffer layer is presented. For the back contact we employed carbon, deposited by simple knife coating method. Different parameters including type of buffer, thickness of absorber layer, CIS and In{sub 2}S{sub 3} annealing temperature and morphology were optimized. Our air stable simple device structure consisting of showed promising power conversion efficiency (PCE) of 2.67%. - Highlights: • This work is an effort on the fabrication of all spin-coated CIS solar cells. • A novel molecular-ink route to deposit In{sub 2}S{sub 3} type buffer layer is presented. • The best devices showed power conversion efficiency (PCE) of 2.67%.

Fabrication of novel nanomaterials for polymer electrolyte membrane fuel cells and self-cleaning applications

Science.gov (United States)

Zhang, Lei

Materials scientists have embraced nanoscale materials as allowing new degrees of freedom in materials design, as well as producing completely new and enhanced properties compared with conventional materials. However, most nanofabrication methods are tedious and expensive, or require extreme conditions. This thesis presents efficient methods for generating nanostructured materials under relatively mild chemistry and experimental conditions. The basis of most of this work is porous anodic aluminum oxide (p-AAO) membranes, which have hexagonally close-packed pores and were fabricated following a two-step aluminum anodization procedure. Partially removing the barrier layer of a p-AAO membrane enabled the preparation of silver nanorod arrays using a very simple electrodepostition procedure. One dimensional (1-D) alumina nanostructures were also electrochemically synthesized on the surface of a p-AAO membrane by carefully controlling the anodization parameters. Polyacrylonitrile nanofibers containing platinum salt were fabricated by polymerization of acrylonitrile in p-AAO templates. Subsequent pyrolysis resulted in carbon nanofibers wherein the platinum salt is reduced in-situ to elemental Pt. The Pt nanoparticles are dispersed throughout the carbon nanofibers, have a narrow size range, and are single crystals. Rotating disc electrode voltammetry suggests that the dispersion of Pt nanocrystals in the carbon nanofiber matrix should exhibit excellent electrocatalytic activity. The preparation of catalyst ink and the construction of membrane-electrode-assembly need to be optimized to get better performance in polymer electrolyte membrane fuel cells. Platinum nanoparticles embedded in carbon fibers were also prepared using electrospinning. The prepared platinum nanoparticles are narrowly distributed in size and well dispersed in the carbon matrix. This method can provide a large yield of products with a simple setup and procedure. 2-D arrays of nanopillars made from

Fabrication and Characterization of Thin Film Solar Cell Made from CuIn0.75Ga0.25S2 Wurtzite Nanoparticles

Directory of Open Access Journals (Sweden)

Fengyan Zhang

2013-01-01

Full Text Available CuIn0.75Ga0.25S2 (CIGS thin film solar cells have been successfully fabricated using CIGS Wurtzite phase nanoparticles for the first time. The structure of the cell is Glass/Mo/CIGS/CdS/ZnO/ZnO:Al/Ag. The light absorption layer is made from CIGS Wurtzite phase nanoparticles that are formed from single-source precursors through a microwave irradiation. The Wurtzite phase nanoparticles were converted to Chalcopyrite phase film through a single-step annealing process in the presence of argon and sulfur at 450°C. The solar cell made from Wurtzite phase nanoparticles showed 1.6% efficiency and 0.42 fill factor.

Spatial Patterning of Newly-Inserted Material during Bacterial Cell Growth

Science.gov (United States)

Ursell, Tristan

2012-02-01

In the life cycle of a bacterium, rudimentary microscopy demonstrates that cell growth and elongation are essential characteristics of cellular reproduction. The peptidoglycan cell wall is the main load-bearing structure that determines both cell shape and overall size. However, simple imaging of cellular growth gives no indication of the spatial patterning nor mechanism by which material is being incorporated into the pre-existing cell wall. We employ a combination of high-resolution pulse-chase fluorescence microscopy, 3D computational microscopy, and detailed mechanistic simulations to explore how spatial patterning results in uniform growth and maintenance of cell shape. We show that growth is happening in discrete bursts randomly distributed over the cell surface, with a well-defined mean size and average rate. We further use these techniques to explore the effects of division and cell wall disrupting antibiotics, like cephalexin and A22, respectively, on the patterning of cell wall growth in E. coli. Finally, we explore the spatial correlation between presence of the bacterial actin-like cytoskeletal protein, MreB, and local cell wall growth. Together these techniques form a powerful method for exploring the detailed dynamics and involvement of antibiotics and cell wall-associated proteins in bacterial cell growth.[4pt] In collaboration with Kerwyn Huang, Stanford University.

Fabrication of gold nanodot arrays on a transparent substrate as a nanobioplatform for label-free visualization of living cells

Energy Technology Data Exchange (ETDEWEB)

Jung, Mi; El-Said, Waleed Ahmed; Choi, Jeong-Woo, E-mail: jwchoi@sogang.ac.kr [Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul 121-742 (Korea, Republic of)

2011-06-10

Two-dimensional gold (Au) nanodot arrays on a transparent substrate were fabricated for imaging of living cells. A nanoporous alumina mask with large-area coverage capability was prepared by a two-step chemical wet etching process after a second anodization. Highly ordered Au nanodot arrays were formed on indium-tin-oxide (ITO) glass using very thin nanoporous alumina of approximately 200 nm thickness as an evaporation mask. The large-area Au nanodot arrays on ITO glass were modified with RGD peptide (arginine; glycine; aspartic acid) containing a cysteine (Cys) residue and then used to immobilize human cancer HeLa cells, the morphology of which was observed by confocal microscopy. The confocal micrographs of living HeLa cells on Au nanodot arrays revealed enhanced contrast and resolution, which enabled discernment of cytoplasmic organelles more clearly. These results suggest that two-dimensional Au nanodot arrays modified with RGD peptide on ITO glass have potential as a biocompatible nanobioplatform for the label-free visualization and adhesion of living cells.

Fabrication and Characteristics of ZnO/OAD-InN/PbPc Hybrid Solar Cells Prepared by Oblique-Angle Deposition

Directory of Open Access Journals (Sweden)

Lung-Chien Chen

2012-08-01

Full Text Available In this work, lead phthalocyanine (PbPc and ZnO/InN inorganic semiconductor films prepared by oblique-angle deposition (OAD were layered to form heterojunction organic/inorganic hybrid photovoltaic solar cells. Among the available organic materials, phthalocyanines, particularly the non-planar ones such as PbPc, are notable for their absorption in the visible and near infrared regions. The organic/inorganic hybrid solar cells fabricated on ZnO/OAD-InN/PbPc showed short-circuit current density (J_SC, open-circuit voltage (V_OC, and power conversion efficiencies (η of 1.2 mA/cm², 0.6 V and 0.144%, respectively.

Micro solar concentrators: Design and fabrication for microcells arrays

Science.gov (United States)

Jutteau, Sébastien; Paire, Myriam; Proise, Florian; Lombez, Laurent; Guillemoles, Jean-François

2015-09-01

In this work we look at a micro-concentrating system adapted to a new type of concentrator photovoltaic material, well known for flate-plate applications, Cu(In,Ga)Se2. Cu(In,Ga)Se2 solar cells are polycrystalline thin film devices that can be deposited by a variety of techniques. We proposed to use a microcell architecture [1], [2], with lateral dimensions varying from a few μm to hundreds of μm, to adapt the film cell to concentration conditions. A 5% absolute efficiency increase on Cu(In,Ga)Se2 microcells at 475 suns has been observed for a final efficiency of 21.3%[3]. We study micro-concentrating systems adapted to the low and middle concentration range, where thin film concentrator cells will lean to substrate fabrication simplification and cost savings. Our study includes optical design, fabrication and experimental tests of prototypes.

Fabrication and electrochemical properties of cathode-supported solid oxide fuel cells via slurry spin coating

International Nuclear Information System (INIS)

Chen Min; Luo Jingli; Chuang, Karl T.; Sanger, Alan R.

2012-01-01

Highlights: ► LSM cathode-supported cell prepared by slurry spin coating. ► Optimizing porosity in CFL resulting in power density of 0.58 W cm −2 at 850 °C. ► Activation polarization govern the impedance arcs measured under the OCV condition. ► Concentration polarization can induce the change of activation polarization. ► Four kinds of polarizations of our cells are separated and investigated. - Abstract: A cathode-supported SOFC consisting of LSM (La 0.8 Sr 0.2 MnO 3−δ ) cathode supporter, LSM–Sm 0.2 Ce 0.8 O 2−δ (SDC) cathode functional layer (CFL), yttria stabilized zirconia (YSZ)/SDC bi-layered electrolyte and Ni-YSZ anode layer was fabricated by a slurry spin coating technique. The influence of the porosity in both the CFL and cathode supporter on the electrochemical properties of the cells has been investigated. It was found that properly controlling the porosity in the CFL would improve the performance of the cells using O 2 in the cathode side (O 2 -cells), with a maximum power density (MPD) value achieving as high as 0.58 W cm −2 at 850 °C. However, this improvement is not so evident for the cells using air in the cathode side (air-cells). When increasing the porosity in the cathode-supporter, a significant increase of the power density for the air cells due to the decreasing R conc,c (cathode concentration polarization to the cell resistance) can be ascertained. In terms of our analysis on various electrochemical parameters, the R act (activation polarization to the cell resistance) is assumed to be mainly responsible for the impedance arcs measured under the OCV condition, with a negligible R conc,c value being able to be detected in our impedances. In this case, a significant decreasing size of the impedance arcs due to the increasing porosity in the cathode supporter would correspond to a decrease of the R act values, which was proved to be induced by the decreasing R conc,c .

Fabrication, Treatment and Testing of a 1.6 Cell Photo-injector Cavity for HZB

International Nuclear Information System (INIS)

Kneisel, P.; Kamps, T.; Knobloch, J.; Kugeler, O.; Neumann, A.; Nietubyc, R.; Sekutowicz, J.K.

2011-01-01

As part of a CRADA (Cooperative Research and Development Agreement) between Forschungszentrum Dresden (FZD) and JLab we have fabricated and tested after appropriate surface treatment a 1.5 cell, 1300 MHz RRR niobium photo-injector cavity to be used in a demonstration test at BESSY*. Following a baseline test at JLab, the cavity received a lead spot coating of ∼ 8 mm diameter deposited with a cathode arc at the Soltan Institute on the endplate made from large grain niobium. It had been demonstrated in earlier tests with a DESY built 1.5 cell cavity - the original design - that a lead spot of this size can be a good electron source, when irradiated with a laser light of 213 nm. In the initial test with the lead spot we could measure a peak surface electric field of ∼ 29 MV/m; after a second surface treatment, carried out to improve the cavity performance, but which was not done with sufficient precaution, the lead spot was destroyed and the cavity had to be coated a second time. This contribution reports about the experiences and results obtained with this cavity.

Polymorphous computing fabric

Science.gov (United States)

Wolinski, Christophe Czeslaw [Los Alamos, NM; Gokhale, Maya B [Los Alamos, NM; McCabe, Kevin Peter [Los Alamos, NM

2011-01-18

Fabric-based computing systems and methods are disclosed. A fabric-based computing system can include a polymorphous computing fabric that can be customized on a per application basis and a host processor in communication with said polymorphous computing fabric. The polymorphous computing fabric includes a cellular architecture that can be highly parameterized to enable a customized synthesis of fabric instances for a variety of enhanced application performances thereof. A global memory concept can also be included that provides the host processor random access to all variables and instructions associated with the polymorphous computing fabric.

New paradigms in internal architecture design and freeform fabrication of tissue engineering porous scaffolds.

Science.gov (United States)

Yoo, Dongjin

2012-07-01

Advanced additive manufacture (AM) techniques are now being developed to fabricate scaffolds with controlled internal pore architectures in the field of tissue engineering. In general, these techniques use a hybrid method which combines computer-aided design (CAD) with computer-aided manufacturing (CAM) tools to design and fabricate complicated three-dimensional (3D) scaffold models. The mathematical descriptions of micro-architectures along with the macro-structures of the 3D scaffold models are limited by current CAD technologies as well as by the difficulty of transferring the designed digital models to standard formats for fabrication. To overcome these difficulties, we have developed an efficient internal pore architecture design system based on triply periodic minimal surface (TPMS) unit cell libraries and associated computational methods to assemble TPMS unit cells into an entire scaffold model. In addition, we have developed a process planning technique based on TPMS internal architecture pattern of unit cells to generate tool paths for freeform fabrication of tissue engineering porous scaffolds. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

W-band LiGA fabricated klystron

Science.gov (United States)

Song, Liqun

2002-01-01

Klystrino-W-band klystron was proposed by scientists at SLAC to satisfy recent applications in advanced accelerators, medical treatment, radars and communications. LiGA (a German acronym for lithographe, galvanoformung, and abformung) is introduced in the fabrication of klystrino for the first time in the history of microwave tube fabrication. The cold test experiments show that LiGA fabrication yields best surface smoothness compared with an alternative way EDM (Electrical Discharge Machining). Resultantly LiGA fabricated klystrino has the smallest wall loss which maximizes the circuit efficiency of the output structure. A multiple-gap coupled cavity is motivated to be employed as the klystrino output cavity for maximizing the efficiency. Klytrino is simulated by 1-D, 2-D and 3-D simulation codes. Particularly a complete klystrino is simulated intensively using 2-D MAGIC Particle-in-Cell (PIC) code either for beam absence or beam presence. Many simulation techniques are developed such as model transformation from 3-D to 2-D, circuit parameter simulation, dispersion characteristic analysis, pre bunched electron beam mode and so on. Klystrino, as a 3-D structure, is modeled by 3-D MAFIA for analyzing the cold circuit properties. 3-D MAGIC is explored to simulate klystrino for the actual structure analysis and actual beam interaction process observation.

Establishment probability in newly founded populations

Directory of Open Access Journals (Sweden)

Gusset Markus

2012-06-01

Full Text Available Abstract Background Establishment success in newly founded populations relies on reaching the established phase, which is defined by characteristic fluctuations of the population’s state variables. Stochastic population models can be used to quantify the establishment probability of newly founded populations; however, so far no simple but robust method for doing so existed. To determine a critical initial number of individuals that need to be released to reach the established phase, we used a novel application of the “Wissel plot”, where –ln(1 – P0(t is plotted against time t. This plot is based on the equation P0t=1–c1e–ω1t, which relates the probability of extinction by time t, P0(t, to two constants: c1 describes the probability of a newly founded population to reach the established phase, whereas ω1 describes the population’s probability of extinction per short time interval once established. Results For illustration, we applied the method to a previously developed stochastic population model of the endangered African wild dog (Lycaon pictus. A newly founded population reaches the established phase if the intercept of the (extrapolated linear parts of the “Wissel plot” with the y-axis, which is –ln(c1, is negative. For wild dogs in our model, this is the case if a critical initial number of four packs, consisting of eight individuals each, are released. Conclusions The method we present to quantify the establishment probability of newly founded populations is generic and inferences thus are transferable to other systems across the field of conservation biology. In contrast to other methods, our approach disaggregates the components of a population’s viability by distinguishing establishment from persistence.

Bioprinting-Based High-Throughput Fabrication of Three-Dimensional MCF-7 Human Breast Cancer Cellular Spheroids

Directory of Open Access Journals (Sweden)

Kai Ling

2015-06-01

Full Text Available Cellular spheroids serving as three-dimensional (3D in vitro tissue models have attracted increasing interest for pathological study and drug-screening applications. Various methods, including microwells in particular, have been developed for engineering cellular spheroids. However, these methods usually suffer from either destructive molding operations or cell loss and non-uniform cell distribution among the wells due to two-step molding and cell seeding. We have developed a facile method that utilizes cell-embedded hydrogel arrays as templates for concave well fabrication and in situ MCF-7 cellular spheroid formation on a chip. A custom-built bioprinting system was applied for the fabrication of sacrificial gelatin arrays and sequentially concave wells in a high-throughput, flexible, and controlled manner. The ability to achieve in situ cell seeding for cellular spheroid construction was demonstrated with the advantage of uniform cell seeding and the potential for programmed fabrication of tissue models on chips. The developed method holds great potential for applications in tissue engineering, regenerative medicine, and drug screening.

Study and Fabrication of Super Low-Cost Solar Cell (SLC-SC) Based on Counter Electrode from Animal’s Bone

Science.gov (United States)

Fadlilah, D. R.; Fajar, M. N.; Aini, A. N.; Haqqiqi, R. I.; Wirawan, P. R.; Endarko

2018-04-01

The synthesized carbon from bones of chicken, cow, and fish with the calcination temperature at 450 and 600°C have been successfully fabricated for counter electrode in the Super Low-Cost Solar Cell (SLC-LC) based the structure of Dye-Sensitized Solar Cells (DSSC). The main proposed study was to fabricate SLC-SC and investigate the influence of the synthesized carbon from animal’s bone for counter electrode towards to photovoltaic performance of SLC-SC. X-Ray Diffraction and UV-Vis was used to characterize the phase and the optical properties of TiO2 as photoanode in SLC-SC. Meanwhile, the morphology and particle size distribution of the synthesized carbon in counter electrodes were investigated by Scanning Electron Microscopy (SEM) and Particle Size Analyzer (PSA). The results showed that the TiO2 has anatase phase with the absorption wavelength of 300 to 550 nm. The calcination temperature for synthesizing of carbon could affect morphology and particle size distribution. The increasing temperature gave the effect more dense in morphology and increased the particle size of carbon in the counter electrode. Changes in morphology and particle size of carbon give effect to the performance of the SLC-SC where the increased morphology’s compact and particle size make decreased in the performance of the SLC-SC.

Circulating Levels of MicroRNA from Children with Newly Diagnosed Type 1 Diabetes and Healthy Controls: Evidence That miR-25 Associates to Residual Beta-Cell Function and Glycaemic Control during Disease Progression

DEFF Research Database (Denmark)

Nielsen, Lotte B.; Wang, Cheng; Sorensen, Kaspar

2012-01-01

This study aims to identify key miRNAs in circulation, which predict ongoing beta-cell destruction and regeneration in children with newly diagnosed Type 1 Diabetes (T1D). We compared expression level of sera miRNAs from new onset T1D children and age-matched healthy controls and related the miRN...

Fabrication and actuation of electro-active polymer actuator based on PSMI-incorporated PVDF

Science.gov (United States)

Lu, Jun; Kim, Sang-Gyun; Lee, Sunwoo; Oh, Il-Kwon

2008-08-01

In this study, an ionic networking membrane (INM) of poly(styrene-alt-maleimide) (PSMI)-incorporated poly(vinylidene fluoride) (PVDF) was applied to fabricate electro-active polymer. Based on the same original membrane of PSMI-incorporated PVDF, various samples of INM actuator were prepared for different reduction times with the electroless-plating technique. The as-prepared INM actuators were tested in terms of surface resistance, platinum morphology, resonance frequency, tip displacement, current and blocked force, and their performances were compared to those of the widely used traditional Nafion actuator. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that much smaller and more uniform platinum particles were formed on the surfaces of the INM actuators as well as within their polymer matrix. Although excellent harmonic responses were observed for the newly developed INM actuators, they were found to be sensitive to the applied reduction times during the fabrication. The mechanical displacement of the INM actuator fabricated after the optimum reduction times was much larger than that of its Nafion counterpart of comparable thickness under the stimulus of constant and alternating current voltage. The PSMI-incorporated PVDF actuator can become a promising smart material to be used in the fields of biomimetic robots, biomedical devices, sensors and actuator, haptic interfaces, energy harvesting and so on.

Fabrication and actuation of electro-active polymer actuator based on PSMI-incorporated PVDF

International Nuclear Information System (INIS)

Lu, Jun; Oh, Il-Kwon; Kim, Sang-Gyun; Lee, Sunwoo

2008-01-01

In this study, an ionic networking membrane (INM) of poly(styrene-alt-maleimide) (PSMI)-incorporated poly(vinylidene fluoride) (PVDF) was applied to fabricate electro-active polymer. Based on the same original membrane of PSMI-incorporated PVDF, various samples of INM actuator were prepared for different reduction times with the electroless-plating technique. The as-prepared INM actuators were tested in terms of surface resistance, platinum morphology, resonance frequency, tip displacement, current and blocked force, and their performances were compared to those of the widely used traditional Nafion actuator. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that much smaller and more uniform platinum particles were formed on the surfaces of the INM actuators as well as within their polymer matrix. Although excellent harmonic responses were observed for the newly developed INM actuators, they were found to be sensitive to the applied reduction times during the fabrication. The mechanical displacement of the INM actuator fabricated after the optimum reduction times was much larger than that of its Nafion counterpart of comparable thickness under the stimulus of constant and alternating current voltage. The PSMI-incorporated PVDF actuator can become a promising smart material to be used in the fields of biomimetic robots, biomedical devices, sensors and actuator, haptic interfaces, energy harvesting and so on

Efficiency enhancement of perovskite solar cells by fabricating as-prepared film before sequential spin-coating procedure

International Nuclear Information System (INIS)

Jiang, Jiajia; Tao, Hai jun; Chen, Shanlong; Tan, Bin; Zhou, Ning; Zhu, Lumin; Zhao, Yuan; Wang, Yuqiao; Tao, Jie

2016-01-01

Graphical abstract: Schematic illustration of modified two-step spin-coating procedure for MAPbI 3 perovskite thin films. - Highlights: • An as-prepared CH 3 NH 3 PbI 3 and PbI 2 film was introduced before the traditional two-step process. • Smooth morphology and trace amount of remaining PbI 2 benefit the performance of solar cell. • The optimal as-prepared film introduced improves the efficiency of CH 3 NH 3 PbI 3 solar cells from 9.11% to 11.16%. - Abstract: Sequential spin-coating procedure is a widely adopted strategy to prepare CH 3 NH 3 PbI 3 on mesostructured TiO 2 electrode for organolead halide perovskite-based solar cells. However, this method suffers from the rough surface and excessively residual PbI 2 in the resulting perovskite film, deteriorating the device performance seriously. Herein, a facial modified sequential solution deposition method, by introducing an as-prepared CH 3 NH 3 PbI 3 and PbI 2 film before the traditional two-step process, was proposed to fabricate the perovskite-based solar cell with smooth morphology and trace amount of remaining PbI 2 . The optimal as-prepared film introduced improves the efficiency of CH 3 NH 3 PbI 3 solar cells from 9.11% to 11.16%. The enhancement of device performance can be attributed to the increased light absorption ability and decreased recombination rate of carriers in CH 3 NH 3 PbI 3 absorber.

Fabrication and characterization of bio-engineered cardiac pseudo tissues

Energy Technology Data Exchange (ETDEWEB)

Xu Tao; Boland, Thomas [Department of Bioengineering, 420 Rhodes Hall, Clemson University, Clemson, SC 29634 (United States); Baicu, Catalin; Aho, Michael; Zile, Michael, E-mail: tboland@clemson.ed [Department of Medicine, Medical University of South Carolina, Charleston, SC 29425 (United States)

2009-09-15

We report on fabricating functional three-dimensional (3D) tissue constructs using an inkjet based bio-prototyping method. With the use of modified inkjet printers, contractile cardiac hybrids that exhibit the forms of the 3D rectangular sheet and even the 'half heart' (with two connected ventricles) have been fabricated by arranging alternate layers of biocompatible alginate hydrogels and mammalian cardiac cells according to pre-designed 3D patterns. In this study, primary feline adult and H1 cardiomyocytes were used as model cardiac cells. Alginate hydrogels with controlled micro-shell structures were built by spraying cross-linkers in micro-drops onto un-gelled alginic acid. The cells remained viable in constructs as thick as 1 cm due to the programmed porosity. Microscopic and macroscopic contractile functions of these cardiomyocyte constructs were observed in vitro. These results suggest that the inkjet bio-prototyping method could be used for hierarchical design of functional cardiac pseudo tissues, balanced with porosity for mass transport and structural support.

Fabrication and characterization of bio-engineered cardiac pseudo tissues

International Nuclear Information System (INIS)

Xu Tao; Boland, Thomas; Baicu, Catalin; Aho, Michael; Zile, Michael

2009-01-01

We report on fabricating functional three-dimensional (3D) tissue constructs using an inkjet based bio-prototyping method. With the use of modified inkjet printers, contractile cardiac hybrids that exhibit the forms of the 3D rectangular sheet and even the 'half heart' (with two connected ventricles) have been fabricated by arranging alternate layers of biocompatible alginate hydrogels and mammalian cardiac cells according to pre-designed 3D patterns. In this study, primary feline adult and H1 cardiomyocytes were used as model cardiac cells. Alginate hydrogels with controlled micro-shell structures were built by spraying cross-linkers in micro-drops onto un-gelled alginic acid. The cells remained viable in constructs as thick as 1 cm due to the programmed porosity. Microscopic and macroscopic contractile functions of these cardiomyocyte constructs were observed in vitro. These results suggest that the inkjet bio-prototyping method could be used for hierarchical design of functional cardiac pseudo tissues, balanced with porosity for mass transport and structural support.

Fabrication of Dye-Sensitized Solar Cells with a 3D Nanostructured Electrode

Directory of Open Access Journals (Sweden)

Guo-Yang Chen

2010-01-01

Full Text Available A novel Dye-Sensitized Solar Cell (DSSC scheme for better solar conversion efficiency is proposed. The distinctive characteristic of this novel scheme is that the conventional thin film electrode is replaced by a 3D nanostructured indium tin oxide (ITO electrode, which was fabricated using RF magnetron sputtering with an anodic aluminum oxide (AAO template. The template was prepared by immersing the barrier-layer side of an AAO film into a 30 wt% phosphoric acid solution to produce a contrasting surface. RF magnetron sputtering was then used to deposit a 3D nanostructured ITO thin film on the template. The crystallinity and conductivity of the 3D ITO films were further enhanced by annealing. Titanium dioxide nanoparticles were electrophoretically deposited on the 3D ITO film after which the proposed DSSC was formed by filling vacant spaces in the 3D nanostructured ITO electrode with dye. The measured solar conversion efficiency of the device was 0.125%. It presents a 5-fold improvement over that of conventional spin-coated TiO2 film electrode DSSCs.

The impact of fabrication parameters and substrate stiffness in direct writing of living constructs.

Science.gov (United States)

Tirella, Annalisa; Ahluwalia, Arti

2012-01-01

Biomolecules and living cells can be printed in high-resolution patterns to fabricate living constructs for tissue engineering. To evaluate the impact of processing cells with rapid prototyping (RP) methods, we modeled the printing phase of two RP systems that use biomaterial inks containing living cells: a high-resolution inkjet system (BioJet) and a lower-resolution nozzle-based contact printing system (PAM(2)). In the first fabrication method, we reasoned that cell damage occurs principally during drop collision on the printing surface, in the second we hypothesize that shear stresses act on cells during extrusion (within the printing nozzle). The two cases were modeled changing the printing conditions: biomaterial substrate stiffness and volumetric flow rate, respectively, in BioJet and PAM(2). Results show that during inkjet printing impact energies of about 10(-8) J are transmitted to cells, whereas extrusion energies of the order of 10(-11) J are exerted in direct printing. Viability tests of printed cells can be related to those numerical simulations, suggesting a threshold energy of 10(-9) J to avoid permanent cell damage. To obtain well-defined living constructs, a combination of these methods is proposed for the fabrication of scaffolds with controlled 3D architecture and spatial distribution of biomolecules and cells. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

Formation of Neural Networks in 3D Scaffolds Fabricated by Means of Laser Microstereolithography.

Science.gov (United States)

Vedunova, M V; Timashev, P S; Mishchenko, T A; Mitroshina, E V; Koroleva, A V; Chichkov, B N; Panchenko, V Ya; Bagratashvili, V N; Mukhina, I V

2016-08-01

We developed and tested new 3D scaffolds for neurotransplantation. Scaffolds of predetermined architectonic were prepared using microstereolithography technique. Scaffolds were highly biocompatible with the nervous tissue cells. In vitro studies showed that the material of fabricated scaffolds is not toxic for dissociated brain cells and promotes the formation of functional neural networks in the matrix. These results demonstrate the possibility of fabrication of tissue-engineering constructs for neurotransplantation based on created scaffolds.

The requirement for freshly isolated human colorectal cancer (CRC) cells in isolating CRC stem cells.

Science.gov (United States)

Fan, F; Bellister, S; Lu, J; Ye, X; Boulbes, D R; Tozzi, F; Sceusi, E; Kopetz, S; Tian, F; Xia, L; Zhou, Y; Bhattacharya, R; Ellis, L M

2015-02-03

Isolation of colorectal cancer (CRC) cell populations enriched for cancer stem cells (CSCs) may facilitate target identification. There is no consensus regarding the best methods for isolating CRC stem cells (CRC-SCs). We determined the suitability of various cellular models and various stem cell markers for the isolation of CRC-SCs. Established human CRC cell lines, established CRC cell lines passaged through mice, patient-derived xenograft (PDX)-derived cells, early passage/newly established cell lines, and cells directly from clinical specimens were studied. Cells were FAC-sorted for the CRC-SC markers CD44, CD133, and aldehyde dehydrogenase (ALDH). Sphere formation and in vivo tumorigenicity studies were used to validate CRC-SC enrichment. None of the markers studied in established cell lines, grown either in vitro or in vivo, consistently enriched for CRC-SCs. In the three other cellular models, CD44 and CD133 did not reliably enrich for stemness. In contrast, freshly isolated PDX-derived cells or early passage/newly established CRC cell lines with high ALDH activity formed spheres in vitro and enhanced tumorigenicity in vivo, whereas cells with low ALDH activity did not. PDX-derived cells, early passages/newly established CRC cell lines and cells from clinical specimen with high ALDH activity can be used to identify CRC-SC-enriched populations. Established CRC cell lines should not be used to isolate CSCs.

Perspective: Fabrication of integrated organ-on-a-chip via bioprinting.

Science.gov (United States)

Yang, Qingzhen; Lian, Qin; Xu, Feng

2017-05-01

Organ-on-a-chip has emerged as a powerful platform with widespread applications in biomedical engineering, such as pathology studies and drug screening. However, the fabrication of organ-on-a-chip is still a challenging task due to its complexity. For an integrated organ-on-a-chip, it may contain four key elements, i.e., a microfluidic chip, live cells/microtissues that are cultured in this chip, components for stimulus loading to mature the microtissues, and sensors for results readout. Recently, bioprinting has been used for fabricating organ-on-a-chip as it enables the printing of multiple materials, including biocompatible materials and even live cells in a programmable manner with a high spatial resolution. Besides, all four elements for organ-on-a-chip could be printed in a single continuous procedure on one printer; in other words, the fabrication process is assembly free. In this paper, we discuss the recent advances of organ-on-a-chip fabrication by bioprinting. Light is shed on the printing strategies, materials, and biocompatibility. In addition, some specific bioprinted organs-on-chips are analyzed in detail. Because the bioprinted organ-on-a-chip is still in its early stage, significant efforts are still needed. Thus, the challenges presented together with possible solutions and future trends are also discussed.

Newly Emerging Immune Checkpoints: Promises for Future Cancer Therapy

Directory of Open Access Journals (Sweden)

Robert J. Torphy

2017-12-01

Full Text Available Cancer immunotherapy has been a great breakthrough, with immune checkpoint inhibitors leading the way. Despite the clinical effectiveness of certain immune checkpoint inhibitors, the overall response rate remains low, and the effectiveness of immunotherapies for many tumors has been disappointing. There is substantial interest in looking for additional immune checkpoint molecules that may act as therapeutic targets for cancer. Recent advances during the last decade have identified several novel immune checkpoint targets, including lymphocyte activation gene-3 (LAG-3, B and T lymphocyte attenuator (BTLA, programmed death-1 homolog (PD-1H, T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIM-3/carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1, and the poliovirus receptor (PVR-like receptors. The investigations into these molecules have generated promising results in preclinical studies. Herein, we will summarize our current progress and understanding of these newly-characterized immune checkpoints and their potential application in cancer immunotherapy.

Submicron three-dimensional structures fabricated by reverse contact UV nanoimprint lithography

DEFF Research Database (Denmark)

Kehagias, N.; Reboud, Vincent; Chansin, G.

2006-01-01

The fabrication of a three-dimensional multilayered nanostructure is demonstrated with a newly developed nanofabrication technique, namely, reverse contact ultraviolet nanoimprint lithography. This technique is a combination of reverse nanoimprint lithography and contact ultraviolet lithography....... In this process, a UV cross-linkable polymer and a thermoplastic polymer are spin coated onto a patterned hybrid metal-quartz stamp. These thin polymer films are then transferred from the stamp to the substrate by contact at a suitable temperature and pressure. The whole assembly is then exposed to UV light....... After separation of the stamp and the substrate, the unexposed polymer areas are rinsed away with acetone leaving behind the negative features of the original stamp with no residual layer....

Fabrication and Characterization of CNT-Based Smart Tips for Synchrotron Assisted STM

Directory of Open Access Journals (Sweden)

Hui Yan

2015-01-01

Full Text Available Determination of chemical composition along with imaging at the atomic level provides critical information towards fundamental understanding of the surface of materials and, hence, yields the capability to design new materials by tailoring their ultimate functionalities. Synchrotron X-ray assisted scanning tunneling microscopy (SX-STM is a promising new technique to achieve real space chemically specific atomic mapping. Chemical sensitivity of SX-STM relies on excitation of core electrons by incident X-rays when their energy is tuned to an absorption edge of a particular element. However, along with core-level electrons, photoelectrons are also excited, which yield additional current and interfere with the tunneling current. To reduce the background photoelectron current and to improve ultimate resolution of SX-STM, we have developed and fabricated multiwalled carbon nanotubes (MWCNT based “smart tips” using plasma enhanced chemical vapor deposition and focused ion beam milling. The newly developed CNT-based smart tips, characterized step by step by scanning electron microscopy (SEM during the fabrication process, demonstrate good performance and provide opportunity for realizing atomic chemical mapping.

Evolution of oxygenated cadmium sulfide (CdS:O) during high-temperature CdTe solar cell fabrication

Energy Technology Data Exchange (ETDEWEB)

Meysing, Daniel M.; Reese, Matthew O.; Warren, Charles W.; Abbas, Ali; Burst, James M.; Mahabaduge, Hasitha P.; Metzger, Wyatt K.; Walls, John M.; Lonergan, Mark C.; Barnes, Teresa M.; Wolden, Colin A.

2016-12-01

Oxygenated cadmium sulfide (CdS:O) produced by reactive sputtering has emerged as a promising alternative to conventional CdS for use as the n-type window layer in CdTe solar cells. Here, complementary techniques are used to expose the window layer (CdS or CdS:O) in completed superstrate devices and combined with a suite of materials characterization to elucidate its evolution during high temperature device processing. During device fabrication amorphous CdS:O undergoes significant interdiffusion with CdTe and recrystallization, forming CdS1-yTey nanocrystals whose Te fraction approaches solubility limits. Significant oxygen remains after processing, concentrated in sulfate clusters dispersed among the CdS1-yTey alloy phase, accounting for ~30% of the post-processed window layer based on cross-sectional microscopy. Interdiffusion and recrystallization are observed in devices with un-oxygenated CdS, but to a much lesser extent. Etching experiments suggest that the CdS thickness is minimally changed during processing, but the CdS:O window layer is reduced from 100 nm to 60-80 nm, which is confirmed by microscopy. Alloying reduces the band gap of the CdS:O window layer to 2.15 eV, but reductions in thickness and areal density improve its transmission spectrum, which is well matched to device quantum efficiency. The changes to the window layer in the reactive environments of device fabrication are profoundly different than what occurs by thermal annealing in an inert environment, which produced films with a band gap of 2.4 eV for both CdS and CdS:O. These results illustrate for the first time the significant changes that occur to the window layer during processing that are critical to the performance of CdTe solar cells.

Pre-set extrusion bioprinting for multiscale heterogeneous tissue structure fabrication.

Science.gov (United States)

Kang, Donggu; Ahn, Geunseon; Kim, Donghwan; Kang, Hyun-Wook; Yun, Seokhwan; Yun, Won-Soo; Shim, Jin-Hyung; Jin, Songwan

2018-06-06

Recent advances in three-dimensional bioprinting technology have led to various attempts in fabricating human tissue-like structures. However, current bioprinting technologies have limitations for creating native tissue-like structures. To resolve these issues, we developed a new pre-set extrusion bioprinting technique that can create heterogeneous, multicellular, and multimaterial structures simultaneously. The key to this ability lies in the use of a precursor cartridge that can stably preserve a multimaterial with a pre-defined configuration that can be simply embedded in a syringe-based printer head. The multimaterial can be printed and miniaturized through a micro-nozzle without conspicuous deformation according to the pre-defined configuration of the precursor cartridge. Using this system, we fabricated heterogeneous tissue-like structures such as spinal cords, hepatic lobule, blood vessels, and capillaries. We further obtained a heterogeneous patterned model that embeds HepG2 cells with endothelial cells in a hepatic lobule-like structure. In comparison with homogeneous and heterogeneous cell printing, the heterogeneous patterned model showed a well-organized hepatic lobule structure and higher enzyme activity of CYP3A4. Therefore, this pre-set extrusion bioprinting method could be widely used in the fabrication of a variety of artificial and functional tissues or organs.

Intensity-modulated radiation therapy followed by GDP chemotherapy for newly diagnosed stage I/II extranodal natural killer/T cell lymphoma, nasal type.

Science.gov (United States)

Huang, Yu; Yang, Jianliang; Liu, Peng; Zhou, Shengyu; Gui, Lin; He, Xiaohui; Qin, Yan; Zhang, Changgong; Yang, Sheng; Xing, Puyuan; Sun, Yan; Shi, Yuankai

2017-09-01

Extranodal natural killer (NK)/T cell lymphoma, nasal type (ENKTL) is an aggressive non-Hodgkin lymphoma and the majority of ENKTL cases are diagnosed at the localized stage. Radiotherapy in combination with chemotherapy has been used for localized ENKTL, but the optimal combination treatment modality and the best first-line chemotherapy regimen have not been defined. In this retrospective study, 44 patients with newly diagnosed, stages I/II ENKTL were enrolled and received intensity-modulated radiation therapy (IMRT, 50-56 Gy) followed by GDP (gemcitabine, dexamethasone, and cisplatin) chemotherapy. The median number of chemotherapy cycles per patient was 4 (range, 2-6 cycles). At the end of treatment, the overall response rate was 95% (42/44), including 39 patients (89%) who attained complete response. Two patients developed systemic progression after IMRT. With a median follow-up of 37.5 months, the 3-year overall survival (OS) rate and progression-free survival (PFS) rate were 85% (95% CI, 74 to 96%) and 77% (95% CI, 64 to 91%), respectively. Locoregional and systemic failure rates for this treatment were 9% (4/44) and 14% (6/44), respectively. The most common grades 3 to 4 adverse events included leukopenia (37%), neutropenia (34%), and mucositis (25%). No treatment-related deaths were observed. This study suggested high efficacy and low toxicity of IMRT followed by GDP regimen chemotherapy for newly diagnosed stage I/II ENKTL patients. These results require further investigation in prospective trials.

Design and fabrication of light weight current collectors for direct methanol fuel cells using the micro-electro mechanical system technique

Science.gov (United States)

Sung, Min-Feng; Kuan, Yean-Der; Chen, Bing-Xian; Lee, Shi-Min

The direct methanol fuel cell (DMFC) is suitable for portable applications. Therefore, a light weight and small size is desirable. The main objective of this paper is to design and fabricate a light weight current collector for DMFC usage. The light weight current collector mainly consists of a substrate with two thin film metal layers. The substrate of the current collector is an FR4 epoxy plate. The thin film metal layers are accomplished by the thermo coater technique to coat metal powders onto the substrate surfaces. The developed light weight current collectors are further assembled to a single cell DMFC test fixture to measure the cell performance. The results show that the proposed current collectors could even be applied to DMFCs because they are light, thin and low cost and have potential for mass production.

Multiphoton photochemical crosslinking-based fabrication of protein micropatterns with controllable mechanical properties for single cell traction force measurements

Science.gov (United States)

Tong, Ming Hui; Huang, Nan; Zhang, Wei; Zhou, Zhuo Long; Ngan, Alfonso Hing Wan; Du, Yanan; Chan, Barbara Pui

2016-01-01

Engineering 3D microstructures with predetermined properties is critical for stem cell niche studies. We have developed a multiphoton femtosecond laser-based 3D printing platform, which generates complex protein microstructures in minutes. Here, we used the platform to test a series of fabrication and reagent parameters in precisely controlling the mechanical properties of protein micropillars. Atomic force microscopy was utilized to measure the reduced elastic modulus of the micropillars, and transmission electron microscopy was used to visualize the porosity of the structures. The reduced elastic modulus of the micropillars associated positively and linearly with the scanning power. On the other hand, the porosity and pore size of the micropillars associated inversely and linearly with the scanning power and reagent concentrations. While keeping the elastic modulus constant, the stiffness of the micropillars was controlled by varying their height. Subsequently, the single cell traction forces of rabbit chondrocytes, human dermal fibroblasts, human mesenchymal stem cells, and bovine nucleus pulposus cells (bNPCs) were successfully measured by culturing the cells on micropillar arrays of different stiffness. Our results showed that the traction forces of all groups showed positive relationship with stiffness, and that the chondrocytes and bNPCs generated the highest and lowest traction forces, respectively.

Fabrication of a biocomposite reinforced with hydrophilic eggshell proteins

International Nuclear Information System (INIS)

Kim, GeunHyung; Min, Taijin; Park, Su A; Kim, Wan Doo; Koh, Young Ho

2007-01-01

Soluble eggshell proteins were used as a reinforcing material of electrospun micro/nanofibers for tissue engineering. A biocomposite composed of poly(ε-caprolactone) (PCL) micro/nanofibers and soluble eggshell protein was fabricated with a two-step fabrication method, which is an electrospinning process followed by an air-spraying process. To achieve a stable electrospinning process, we used an auxiliary cylindrical electrode connected with a spinning nozzle. PCL biocomposite was characterized in water contact angle and mechanical properties as well as cell proliferation for its application as a tissue engineering material. It showed an improved hydrophilic characteristic compared with that of a micro/nanofiber web generated from a pure PCL solution using a typical electrospinning process. Moreover, the fabricated biocomposite had good mechanical properties compared to a typical electrospun micro/nanofiber mat. The fabricated biocomposite made human dermal fibroblasts grow better than pure PCL. From the results, the reinforced polymeric micro/nanofiber scaffold can be easily achieved with these modified processes

Fabrication of layered hydroxide zinc nitrate films and their conversion to ZnO nanosheet assemblies for use in dye-sensitized solar cells

Directory of Open Access Journals (Sweden)

Takuya Yuki

2015-03-01

Full Text Available Layered hydroxide zinc nitrate (LHZN; Zn5(NO32(OH8·xH2O films were fabricated on glass or plastic substrates by a chemical bath deposition method combined with a homogeneous precipitation in methanolic solutions. High- or low-temperature pyrolytic decomposition of the LHZN films having two-dimensional morphology was attempted to obtain porous ZnO nanosheet-assembly films. The LHZN films were converted into porous ZnO films by pyrolyzing at temperatures above 400 °C, while porous LHZN/ZnO hybrid films were obtained by pyrolyzing at a lower temperature of 120 °C without morphological changes. The pyrolyzed ZnO films were applied to dye-sensitized solar cells (DSSCs, resulting in the generation of relatively high open-circuit voltages. The low-temperature pyrolysis enabled us to fabricate the LHZN/ZnO film even on the plastic substrate. Actually a cell using the LHZN/ZnO film on an indium tin oxide-coated polyethylene naphthalate substrate showed an energy conversion efficiency of 2.08% with a high open-circuit voltage around 0.70 V.

Hybrid nanostructure heterojunction solar cells fabricated using vertically aligned ZnO nanotubes grown on reduced graphene oxide.

Science.gov (United States)

Yang, Kaikun; Xu, Congkang; Huang, Liwei; Zou, Lianfeng; Wang, Howard

2011-10-07

Using reduced graphene oxide (rGO) films as the transparent conductive coating, inorganic/organic hybrid nanostructure heterojunction photovoltaic devices have been fabricated through hydrothermal synthesis of vertically aligned ZnO nanorods (ZnO-NRs) and nanotubes (ZnO-NTs) on rGO films followed by the spin casting of a poly(3-hexylthiophene) (P3HT) film. The data show that larger interfacial area in ZnO-NT/P3HT composites improves the exciton dissociation and the higher electrode conductance of rGO films helps the power output. This study offers an alternative to manufacturing nanostructure heterojunction solar cells at low temperatures using potentially low cost materials.

Fabrication of superhydrophobic cotton fabrics using crosslinking polymerization method

Science.gov (United States)

Jiang, Bin; Chen, Zhenxing; Sun, Yongli; Yang, Huawei; Zhang, Hongjie; Dou, Haozhen; Zhang, Luhong

2018-05-01

With the aim of removing and recycling oil and organic solvent from water, a facile and low-cost crosslinking polymerization method was first applied on surface modification of cotton fabrics for water/oil separation. Micro-nano hierarchical rough structure was constructed by triethylenetetramine (TETA) and trimesoyl chloride (TMC) that formed a polymeric layer on the surface of the fabric and anchored Al2O3 nanoparticles firmly between the fabric surface and the polymer layer. Superhydrophobic property was further obtained through self-assembly grafting of hydrophobic groups on the rough surface. The as-prepared cotton fabric exhibited superoleophilicity in atmosphere and superhydrophobicity both in atmosphere and under oil with the water contact angle of 153° and 152° respectively. Water/oil separation test showed that the as-prepared cotton fabric can handle with various oil-water mixtures with a high separation efficiency over 99%. More importantly, the separation efficiency remained above 98% over 20 cycles of reusing without losing its superhydrophobicity which demonstrated excellent reusability in oil/water separation process. Moreover, the as-prepared cotton fabric possessed good contamination resistance ability and self-cleaning property. Simulation washing process test showed the superhydrophobic cotton fabric maintained high value of water contact angle above 150° after 100 times washing, indicating great stability and durability. In summary, this work provides a brand-new way to surface modification of cotton fabric and makes it a promising candidate material for oil/water separation.

Fabrication of combined-scale nano- and microfluidic polymer systems using a multilevel dry etching, electroplating and molding process

DEFF Research Database (Denmark)

Tanzi, Simone; Østergaard, Peter Friis; Matteucci, Marco

2012-01-01

Microfabricated single-cell capture and DNA stretching devices have been produced by injection molding. The fabrication scheme employed deep reactive ion etching in a silicon substrate, electroplating in nickel and molding in cyclic olefin polymer. This work proposes technical solutions to fabric......Microfabricated single-cell capture and DNA stretching devices have been produced by injection molding. The fabrication scheme employed deep reactive ion etching in a silicon substrate, electroplating in nickel and molding in cyclic olefin polymer. This work proposes technical solutions...

The use of cloth fabric diffusion layers for scalable microbial fuel cells

KAUST Repository

Luo, Yong

2013-04-01

A scalable and pre-manufactured cloth material (Goretex® fabric) was used as a diffusion layer (DL) material as a replacement for a liquid-applied polytetrafluoroethylene (PTFE) DL. Cathodes with the Goretex fabric heat-bonded to the air-side of carbon cloth cathode (CC-Goretex) produced a maximum power density of 1330±30mW/m2, similar to that using a PTFE DL (1390±70mW/m2, CC-PTFE). This method was also successfully used to produce cathodes made of inexpensive carbon mesh, which resulted in only slightly less power (1180±10mW/m2) (CM-Goretex). Coulombic efficiencies were a function of current density, with the highest value for CC-PTFE cathodes (63%), similar to CC-Goretex cathodes (61%), and slightly larger than that obtained for the CM-Goretex cathodes (54%). These results show that a commercially available fabric can easily be used as the DL in an MFC, achieving performance similar to that obtained with a more labor-intensive process based on liquid-applied DLs using PTFE. © 2013 Elsevier B.V.

Fabrication and evaluation of 3D β-TCP scaffold by novel direct-write assembly method

International Nuclear Information System (INIS)

Sa, Min Woo; Kim, Jong Young

2015-01-01

Various scaffold fabrication methods have been explored to enhance the cell interaction effects and mechanical properties of scaffolds in bone regeneration. Rapid prototyping (RP) for tissue engineering is a useful technology that may provide a potential scaffolding structure to regenerate, restore, and repair a damaged bone tissue or organ, that is, RP is a promising tissue engineering technique through a 3D scaffold fabrication by using a computer-aided design/computer-aided manufacturing system. In this study, 3D β-tricalcium phosphate (β-TCP) scaffolds were fabricated by a novel direct-write assembly method. The mechanical property of β-TCP scaffolds was analyzed by stress-strain curves by using a compression testing machine. Furthermore, an in vitro CCK-8 assay of osteosarcoma MG-63 cells showed the significant cell attachment and proliferation in the β-TCP scaffold.

Fabrication and evaluation of 3D β-TCP scaffold by novel direct-write assembly method

Energy Technology Data Exchange (ETDEWEB)

Sa, Min Woo; Kim, Jong Young [Andong National University, Andong (Korea, Republic of)

2015-11-15

Various scaffold fabrication methods have been explored to enhance the cell interaction effects and mechanical properties of scaffolds in bone regeneration. Rapid prototyping (RP) for tissue engineering is a useful technology that may provide a potential scaffolding structure to regenerate, restore, and repair a damaged bone tissue or organ, that is, RP is a promising tissue engineering technique through a 3D scaffold fabrication by using a computer-aided design/computer-aided manufacturing system. In this study, 3D β-tricalcium phosphate (β-TCP) scaffolds were fabricated by a novel direct-write assembly method. The mechanical property of β-TCP scaffolds was analyzed by stress-strain curves by using a compression testing machine. Furthermore, an in vitro CCK-8 assay of osteosarcoma MG-63 cells showed the significant cell attachment and proliferation in the β-TCP scaffold.

Investigation of nanoporous platinum thin films fabricated by reactive sputtering: Application as micro-SOFC electrode

Science.gov (United States)

Jung, WooChul; Kim, Jae Jin; Tuller, Harry L.

2015-02-01

Highly porous Pt thin films, with nano-scale porosity, were fabricated by reactive sputtering. The strategy involved deposition of thin film PtOx at room temperature, followed by the subsequent decomposition of the oxide by rapid heat treatment. The resulting films exhibited percolating Pt networks infiltrated with interconnected nanosized pores, critical for superior solid oxide fuel cell cathode performance. This approach is particularly attractive for micro-fabricated solid oxide fuel cells, since it enables fabrication of the entire cell stack (anode/electrolyte/cathode) within the sputtering chamber, without breaking vacuum. In this work, the morphological, crystallographic and chemical properties of the porous electrode were systematically varied by control of deposition conditions. Oxygen reduction reaction kinetics were investigated by means of electrochemical impedance spectroscopy, demonstrating the critical role of nano-pores in achieving satisfactory micro-SOFC cathode performance.