Search

A foldable array of patterned graphene/ZnO nanoparticle UV sensor and asymmetric micro-supercapacitors (AMSCs) integrated on a paper substrate with patterned liquid metal interconnections is reported. The resistor type UV sensor based on graphene/ZnO nanoparticles is patterned to be driven by the stored energy of the integrated AMSCs. The AMSC consists of MnO2 nanoball deposited multiwalled carbon nanotubes (MWNTs) and V2O5 wrapped MWNTs as positive and negative electrodes, respectively. As an electrolyte, propylene carbonate-poly(methyl methacrylate)-LiClO4, an organic solvent-based gel, is used. The UV sensor and AMSCs can be easily integrated on a liquid metal, Galinstan, patterned, waterproof mineral paper and show a mechanically stable UV sensing, regardless of repetitive folding cycles. This work demonstrates a novel foldable nanomaterial based sensor system driven by integrated energy storage devices, applicable to future wearable and portable electronics.

Background Discharge disposition planning is vital for poststroke patients. We investigated clinical factors associated with discharging patients to nursing homes, using the Taiwan Stroke Registry data collected from 39 major hospitals. Methods We randomly assigned 21,575 stroke inpatients registered from 2006 to 2008 into derivation and validation groups at a 3-to-1 ratio. We used the derivation group to develop a prediction model by measuring cumulative risk scores associated with potential predictors: age, sex, hypertension, diabetes mellitus, heart diseases, stroke history, snoring, main caregivers, stroke types, and National Institutes of Health Stroke Scale (NIHSS). Probability of nursing home care and odds ratio (OR) of nursing home care relative to home care by cumulative risk scores were measured for the prediction. The area under the receiver operating characteristic curve (AUROC) was used to assess the model discrimination against the validation group. Results Except for hypertension, all remaining potential predictors were significant independent predictors associated with stroke patient disposition to nursing home care after discharge from hospitals. The risk sharply increased with age and NIHSS. Patients with a cumulative risk score of 15 or more had an OR of 86.4 for the nursing home disposition. The AUROC plots showed similar areas under curves for the derivation group (.86, 95% confidence interval [CI], .85-.87) and for the validation group (.84, 95% CI, .83-.86). Conclusions The cumulative risk score is an easy-to-estimate tool for preparing stroke patients and their family for disposition on discharge.

With the development of mobile technology, attendance check has been digitalized, and digital check attendance system in connection with RFID system started to be used. However, it costs a lot to establish and maintain such a system. In this thesis was developed the student attendance check system which detects geographical locations of smart phones and processes attendance check through mobile or smart devices. The developed system continuously measured the distance of two users to analyze the changing pattern of distance values to judge attendance, instead of using the instantly measured instance of two users as the data used to judge attendance.

We report the influence of porosity and pore size on perovskite solar cell efficiency. We demonstrate an alternative electrode synthesis route that goes beyond traditional paste processing by incorporating a second distribution of nanoparticles composed of ZnO into the TiO 2 paste. After calcination to form a mesoporous film, the ZnO nanoparticles are selectively etchable under acidic conditions to lead to additional mesorporosity in the TiO 2 . These modified films exhibit increased perovskite loading for a given thickness and led to improved current densities and power conversion efficiencies. We anticipate that this additional mesoporosity control may be beneficial for numerous other applications.

In this paper, problems that additional hardwares should be introduced due to the introduction of new servers are reduced by reducing the space on the top surface of the computer data center after many old physical UNIX servers are loaded on one new virtualization consolidation server. In addition, some effects for reducing the computer maintenance cost and the power consumption of the computer data center could be generated. With such virtualization of UNIX server consolidation, it is expected that the maintenance cost of the computer center will be reduced in the future as well as currently and IT will be changed into green-IT. The method for establishing a virtualization of server consolidation which is applied in this paper can be applied in the same way that other group of servers are consolidation.

This paper deals with the general field of Electrical Engineering. Its primary goal is to design a digital Proportional-Integral-Derivative controller in a PLD’s devices environment to control the speed of DC motor system. This DC motor system composed of two similar motors one act as motor and the other act as generator, speed controlling of this DC motor done by pulse width modulation (PWM) system. Two major problems attempted to address in this paper by means of a PID controller. The first problem was system non-linearity that arose due to the nature of the hardware. The second problem was system unreliability when the DC motor load was varied.

Additional photon-harvesting by hole transporting materials in Sb(2)S(3)-sensitized solar cell is demonstrated through the formation of electron channels in the hole transporter such as P3HT (poly(3-hexylthiophene)) and PCPDTBT(poly(2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7(2,1,3-benzothiadiazole)) that can act as both a hole conductor and light absorber. As a result, the short-circuit current density is improved with an increment in overall efficiency. These findings provide new insights into use of light-absorbing conjugated polymers as a hole conductor in the inorganic-organic heterojunction sensitized solar cells.

A mesoporous (mp)-TiO(2)/Sb(2)S(3)/P3HT [poly(3-hexylthiophene)] heterojunction solar cell displays reduced external quantum efficiency (EQE) at a wavelength of approximately 650 nm. This loss in EQE is due to incomplete charge carrier transport because the transportation of charge carriers generated in P3HT by the absorption of light into Sb(2)S(3) was inefficient, and consequently, the carriers recombined. The depression of the EQE was greatly relieved by introducing the porous structure formed by thermal decomposition of 2,2'-azobisisobutyronitrile (AIBN) into the P3HT layer.

The CdS-sensitized solar cells (CdS-SSC) were fabricated by spray pyrolysis deposition (SPD) method. The performance of the cells was greatly improved through post-treatments that included thermal oxidation at 500 degrees C for 30 min in an air atmosphere and subsequent chemical etching by 40 mM aqueous HCl solution at room temperature for 30 min, as compared to as-deposited CdS-SSC. The CdS-SSC in a I(-)/I(3)(-) electrolyte system was resulted in the improvement of J(sc) (3.3 --5.2 mA/cm(2)), V(oc) (697 --758 mV), FF (41.4% --46.9%), and (0.95% --1.84%). Similarly, the efficiency of CdS-SSC in a noncorrosive polysulfide electrolyte system was also enhanced by the proposed thermal oxidation and etching process. The increase in the cell efficiency is attributed to the reduced charge recombination among sensitizer themselves through the mitigation of overaggregated CdS sensitizers deposited by SPD.

We report all solid-state nanostructured inorganic-organic heterojunction solar cells fabricated by depositing Sb(2)S(3) and poly(3-hexylthiophene) (P3HT) on the surface of a mesoporous TiO(2) layer, where Sb(2)S(3) acts as an absorbing semiconductor and P3HT acts as both a hole conductor and light absorber. These inorganic-organic light harvesters perform remarkably well with a maximum incident-photon-to-current efficiency (IPCE) of 80% and power conversion efficiency of 5.13% under air-mass 1.5 global (AM 1.5G) illumination with the intensity of 100 mW cm(-2). These devices are highly stable under room light in air, even without encapsulation. The present findings offer novel directions for achieving high-efficiency solid-state solar cells by hybridization of inorganic-organic light harvesters and hole transporters.

Nanocrystalline CdS-sensitized solar cells (CdS-SSCs) based on mesoporous TiO(2) were fabricated by the spray pyrolysis deposition method. The energy conversion efficiency of these cells was drastically increased (156%) by modifying the junction structure through post-treatment that included soaking in a dilute TiCl(4) aqueous solution and subsequent thermal annealing. We propose that the post-treatment is responsible for an increased number of interconnections between TiO(2) and CdS, as well as surface passivation of the CdS sensitizer. The increase in the cell efficiency is attributed to the improved charge carrier transport, suppression of photoelectron recombination with holes both in the same sensitizer particle and in nearby ones, and suppression of photoelectron capture by the electrolyte.

Atherosclerosis of the intracranial arteries is a well-recognized cause of ischemic stroke in Asians, and extracranial carotid artery disease is more often seen in western countries. The relationship of common carotid artery intima-media thickness (CCA-IMT), intracranial arteries stenosis (ICS) and vascular cognitive impairment (VCI) after ischemic stroke has not been fully elucidated. In this study, we investigated the relationship between CCA-IMT and the severity of ICS and VCI.We recruited patients from December 2004, to June 2005, with the inclusion criteria: (1) first-ever ischemic stroke, (2) admission within 3 days of stroke onset, (3) under 80 years old, and (4) no previous dementia history. We excluded patients with stroke scores greater than an NIHSS of 15; those with recurrent stroke, and those with extracranial internal carotid artery stenosis50%. All the patients underwent brain MR angiography, carotid ultrasonography and neuropsychological testing during hospitalization and at 3 months after stroke. We defined the percent of ICS using the method of Warfarin-Aspirin Symptomatic Intracranial Disease. Measurement of CCA-IMT was made on the far wall of the common carotid artery, 1.5 cm proximal to the bifurcation at a point free of plaques. Cognitive performance was assessed using the Cognition Assessment State Instrument (CASI).Thirty patients (21M/9F, mean age 65.97 +/- 10.33 years) were studied. The initial CCA-IMT was 1.04 +/- 0.59 mm and the initial CASI was 64.73 +/- 14.75. The ICS was 70 +/- 26%. At 3 months after stroke, the CCA-IMT was 1.06 +/- 0.59 mm; and CASI was 70.07 +/- 18.50. Compared with patients with CCA-IMT0.87 mm, those with CCA-IMTor = 0.87 mm had lower ICS (57 +/- 23% vs. 81 +/- 24%, p = 0.013), but similar initial CASI score (67.92 +/- 13.52 vs. 61.93 +/- 16.64, p = 0.28). The improvement of CASI score at 3 months was significantly higher in patients with CCA-IMTor = 0.87 mm (67.92 +/- 13.52 vs. 77.36 +/- 14.12, p = 0.001), than those with CCA-IMT0.87 mm (61.93 +/- 16.64 vs. 63.69 +/- 19.89, p = 0.612).CCA-IMT might be associated with the severity of ICS and VCI at 3 months after the first-ever ischemic stroke. The patients with lower CCA-IMT had a better CASI evaluation at 3 months after stroke. A larger scale of study to explore the association of CCA-IMT, VCI and ICS at 3 months after stroke might help farther delineation of these relationships.

Dr. Y. C. Choi, Dr. Y. H. Lee, Dr. J. H. Noh, Dr. T. N. Mandal, W. S. Yang, Dr. S. I. Seok Division of Advanced Materials Korea Research Institute of Chemical Technology 141 Gajeong-Ro, Yuseong-Gu, Daejeon , 305.600 , Republic of Korea Prof. S. H. Im Department of Chemical Engineering Kyung Hee University oungin-si , Y 446–701 , Republic of Korea Prof. S. I. Seok Department of Energy Science Sungkyunkwan University Suwon , 440–746 , Republic of Korea E-mail: seoksi@skku.edu

Performance of Sb(2)S(3)-sensitized heterojunction solar cells is enhanced by embedding Au nanoparticles in the poly-3-hexylthiophene (P3HT) hole-conducting polymer layer. The improved charge transfer/transport at the Sb(2)S(3)/P3HT/Au interface by extended interface area of the P3HT/Au counter electrode and the re-absorption of the backscattering light from the embedded Au nanoparticles enhanced the device performance: J(sc) 11.0 to 12.8 mA cm(-2), V(oc) 606 to 626 mV, fill factor (FF) 60.5 to 61.2%, and power conversion efficiency (η) 4.0 to 4.9%. Simultaneous enhancement of V(oc), J(sc), and FF in Au nanoparticle-embedded systems is mainly attributed to the improved charge collection efficiency and light harvesting efficiency of Sb(2)S(3) due to the improved charge transfer/transport in the Sb(2)S(3)/P3HT/Au interface.

Augmentation of the body contour by localized injection of hard and soft paraffin rose to a zenith of popularity in the early 1900s, whereafter the severe destructive consequences of such injections became widely recognized. However in Korea, these injections are still performed much by nonmedical person. Paraffin or other mineral oil injection into body is no more a useful method to change body contour. We reviewed 26 cases of sclerosing lipogranuloma of penis with complications in recent 13 years after mean 18.5 months from previous injection of paraffin or vaseline. We conclude that the public should be informed of detrimental effects of paraffin injections and that the best treatment of penile paraffinoma is complete excision and appropriate penoplasty.

Nanorods of Sb2Se3 have been produced from a newly designed single-source precursor under assistance of ethylene glycol used as solvent without any surfactants or additives. The precursor, [(SbL2Cl2)Cl]2·(CH3)2CO, 1 (L represents N,N-dimethyl selenourea)], has been easily synthesized and characterized by single crystal X-ray diffraction and IR spectroscopy. The extensive network of NH–Cl bonds present in the crystal packing of the complex promoted the formation of Sb2Se3, leaving HCl in the reaction medium. The Sb2Se3 nanocompounds have been characterized by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). The mechanism of formation of Sb2Se3 has been proposed and rationalized on the basis of TEM and field emission scanning electron microscopy (FE-SEM) observations of the intermediates throughout the solvent-assisted growth and mass spectral analysis of the reaction mixture during the process.

Inorganic-organic hybrid structures have become innovative alternatives for next-generation dye-sensitized solar cells, because they combine the advantages of both systems. Here, we introduce a layered sandwich-type architecture, the core of which comprises a bicontinuous three-dimensional nanocomposite of mesoporous (mp)-TiO2, with CH(3)NH(3)Pbl(3) perovskite as light harvester, as well as a polymeric hole conductor. This platform creates new opportunities for the development of low-cost, solution-processed, high-efficiency solar cells. The use of a polymeric hole conductor, especially poly-triarylamine, substantially improves the open-circuit voltage V-oc and fill factor of the cells. Solar cells based on these inorganic-organic hybrids exhibit a short-circuit current density J(sc) of 16.5 mA cm(-2), V-oc of 0.997 V and fill factor of 0.727, yielding a power conversion efficiency of 12.0% under standard AM 1.5 conditions.

Impressive hybrid photovoltaic device performances have been realised with the methylammonium lead triiodide (MAPbI(3)) perovskite absorber in a wide range of device architectures. However, the question as to which of these systems represents the most commercially viable long-term prospect is yet to be answered conclusively. Here, we report on the photoinduced charge transfer processes in MAPbI(3) based films measured under inert and ambient conditions. When exposed to ambient conditions, the coated mesoporous Al2O3 and bilayer systems show a rapid and significant degradation in the yield of long-lived charge separation. This process, which does not affect sensitized-mesoporous TiO2 films, is only found to occur when both light and oxygen are present. These observations indicate that the presence of a mesostructured TiO2 electron acceptor to rapidly extract the photoexcited electron from the perovskite sensitizer may be crucial for fundamental photovoltaic stability and significantly increases innate tolerance to environmental conditions. This work highlights a significant advantage of retaining mesoscale morphological control in the design of perovskite photovoltaics.

Sb(2)S(3)-sensitized mesoporous-TiO(2) solar cells using several conjugated polymers as hole-transporting materials (HTMs) are fabricated. We found that the cell performance was strongly correlated with the chemical interaction at the interface of Sb(2)S(3) as sensitizer and the HTMs through the thiophene moieties, which led to a higher fill factor (FF), open-circuit voltage (V(oc)), and short-circuit current density (J(sc)). With the application of PCPDTBT (poly(2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7(2,1,3-benzothiadiazole)) as a HTM in a Sb(2)S(3)-sensitized solar cell, overall power conversion efficiencies of 6.18, 6.57, and 6.53% at 100, 50, and 10% solar irradiation, respectively, were achieved with a metal mask.

Efficient sunlight-driven water splitting devices can be achieved by pairing two absorbers of different optimized bandgaps in an optical tandem design. With tunable absorption ranges and cell voltages, organic–inorganic metal halide perovskite solar cells provide new opportunities for tailoring top absorbers for such devices. In this work, semitransparent perovskite solar cells are developed for use as the top cell in tandem with a smaller bandgap photocathode to enable panchromatic harvesting of the solar spectrum. A new CuInxGa1-xSe2 multilayer photocathode is designed, exhibiting excellent performance for photoelectrochemical water reduction and representing a near-ideal bottom absorber. When pairing it below a semitransparent CH3NH3PbBr3-based solar cell, a solar-to-hydrogen efficiency exceeding 6% is achieved, the highest value yet reported for a photovoltaic–photoelectrochemical device utilizing a single-junction solar cell as the bias source under one sun illumination. The analysis shows that the efficiency can reach more than 20% through further optimization of the perovskite top absorber.

A new type of hole transporting material (HTMs) with an incorporated planar amine or triphenylamine as a core unit have been prepared. The two amine derivatives were demonstrated to be efficient hole transporting materials in fabricating solid-state organic-inorganic hybrid solar cells. Perovskite-based solar cells with a planar amine derivative gave a short circuit photocurrent density (J(sc)) of 20.98 mAcm(-2), an open circuit voltage (V-oc) of 0.972 V, and a fill factor of 0.67, corresponding to an overall conversion efficiency of 13.63 %. The photovoltaic performance is comparable to that of the standard spiro-OMeTAD. Moreover, the device showed good stability under light soaking for 500 h. These HTMs hold promise to replace the expensive spiro-OMeTAD because of their high efficiency, excellent stability, synthesis from simple and inexpensive materials.