bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Advanced Microstructural and Microchemical Microscopy Techniques to Chalcopyrite Solar Cells.
Authors: Lei Changhui , Li Chun-Ming , Rockett Angus , Robertson I. M. , Shafarman W. 
Published: November 2011

AbstractAnalytical TEM techniques have been used to characterize the structure and chemistry of chalcopyrite solar cell devices produced by elemental evaporation using a bi-layer process at Ts=400°C and Ts=550°C. Dislocations, stacking faults, twins and voids exist in both materials but at a reduced density at the higher deposition temperature. The higher processing temperature also improved the density and structure of the grain boundaries and created a less rough surface. The CdS layer coats the surface conformally, although the roughness impacts the structure. CdS fills the grooves in the surface and infiltrates lower density grain boundaries to significant depths. The chemistry of the grain boundaries does not appear to be significantly impacted by the presence of the Cd and S.
Structural Properties of Ag-Based Chalcopyrite Compound Thin Films for Solar Cells
Authors: Ishizaki Hiroki , Yamada Keiichiro , Arai Ryouta , Kuromiya Yasuyuki , Masatsugu Yukari , Yamada Naoomi , Nakada Tokio 
Published: November 2011

AbstractAgGa5Se8 and Ag(In1-xGax)Se2 thin films with different Ag/Ga atomic ratios have been deposited on the corning 1737 glass substrates by molecular beam epitaxy (MBE) system. This crystallographic property of AgGa5Se8 thin films has been investigated by x-ray diffraction and rietveld analysis. These films had the tetragonal structure with the space group of P-42m, regardless of Ag/Ga atomic ratio. The lattice parameters and the optical band gap energy decreased with an increase in the Ag/Ga atomic ratio. Thus, the structural and optical properties of these AgGa5Se8 thin films were controlled by the Ag/Ga atomic ratio.
Photostimulated Changes of Electrical Characteristics of Ag/CdTe Thin Film Structures
Authors: Dzhafarov T.D. , Caliskan M. 
Published: November 2011

AbstractElectrical, optical and structural properties of Ag/CdTe structures exposed to thermal (in dark) and photoannealing (under illumination) have been studied. The effective diffusion coefficie nt of Ag in CdTe films have been estimated from resistance versus duration of annealing curves. In the range of 280-420°C the effective coefficient of thermal diffusion (Dt) and photodiffusion (Dph) are described as Dt= 1.9x105exp (-1.60/kT) and Dph =8.7x103exp(-1.36/kT). The acceleration of Ag diffusion under illumination was tentatively attributed to photoionization of Ag increasing the interstitial flux of silver. Ag/CdTe structures exposed to annealing were characterized by X-ray diffraction (XRD), I-V, C-V, conductivity-temperature and optical transmission measurements. In XRD patterns of annealed Ag/CdTe structures, besides the intensive (111) peak of cubic CdTe, the weak peaks of Ag2Te phase are also present. The temperature dependence of conductivity of annealed Ag/CdTe structures showed the energy levels 0.13 eV.
Analysis of Proton Induced Defects in Cu(In,Ga)Se2 Thin-Film Solar Cells
Authors: Kawakita Shirou , Imaizumi Mitsuru , Kibe Koichi , Yoda Shinichi , Ohshima Takeshi , Itoh Hisayoshi , Yamaguchi Masafumi 
Published: November 2011

AbstractWe investigated radiation-induced defects in CIGS solar cells with a solar-cell simulator to analyze the spectral response of the irradiated cells. The damage constant of the minority-carrier diffusion length of the cells irradiated with 1 MeV protons was determined to be 3.5 ×10-5. This analysis led to the relation between the defect introduction rate and proton energy, and was obtained using the same method, as was the defect annealing rate. This result agreed well with that estimated from an analysis of changes in short-circuit current degradation.
Physical Vapor Deposition Synthesis of Cu3BiS3 for Application in Thin Film Photovoltaics
Authors: Gerein Nathan J. , Haber Joel A. 
Published: November 2011

AbstractThe development of novel solar absorbers and device configurations that incorporate only materials which are cost effective, abundant, and non-toxic may be required for widespread deployment of photovoltaics. Cu3BiS3 (Eg=1.2 eV) has been previously reported to be a suitable solar absorber for use in thin film photovoltaic devices. We have developed a physical vapor deposition synthesis for Cu3BiS3, and will employ combinatorial methods to identify novel device configurations in an effort to produce a device exhibiting sufficient efficiency to capture the interest of the photovoltaics community.
Thin CuInS2 Films Prepared by MOMBE: Interface and Surface Properties
Authors: Pettenkofer C. , Lehmann C. , Calvet W. 
Published: November 2011

AbstractCuInS2 films were prepared on Si(111) by MOMBE using standard MBE Cu and In sources and Ditertbutyldisulfide (TBDS) as an organic sulfur precursor. The films were analyzed in situ by XPS, LEED and UPS. Deposition at 250°C yields chalcopyrite films [1] with admixtures of CuSi2 and CuIn alloys. Deposition at higher temperatures up to 550°C was used to clarify the feasibility of the process. High quality LEED diffraction patterns show epitaxial growth but CuSi2 precipitations are still observed for deposition on Si(111). A buffer layer of indiumsulfide showed no considerable effect on the interface morphology. The obtained LEED pattern are in accordance with the epitaxial relation Si{111}||CuInS2{112}. Even for temperatures as high as 550°C no incorporation of Carbon or residual hydrocarbons in the film or adsorbed at the surface were detected.
Cello Measurements of CIGS and μcSi Solar Cells
Authors: Mathijssen Stefan , Carstensen Jürgen , Föll Helmut , Voorwinden Georg , Stiebig Helmut 
Published: November 2011

AbstractThe CELLO (solar celllocal characterization) technique, which allows to measure all parameters of a solar cell locally with high spatial resolution, is applied for the first time for thin film solar cells based on Cu(In,Ga)Se2 (CIGS) and micro-crystalline Si (μcSi). Results for local effective serial resistance, photocurrent and current/voltage at the working point will be presented, demonstrating the applicability of CELLO to thin film solar cells. Based on the measurements, quantitative predictions for the potential of these cells will be made.
Open-Circuit Voltage Decay in CdTe/CdS Solar Cells
Authors: Price Kent , Cooper Kevin , Lacy Chris 
Published: November 2011

AbstractOpen-Circuit Voltage Decay (OCVD) is a common technique used to characterize numerous semiconductor devices. However, to the knowledge of the authors, the technique has not previously been applied to CdTe-based solar cells. We use a simple setup consisting of a function generator, rectifying diode, and digital oscilloscope to measure the dark open circuit voltage decay as a function of time across a CdTe solar cell. We find the decay to be described by the equation v(t) = v0 + A1exp (–t/τ1) + A2exp (–t/τ2) where v is the voltage, t is time, τ1 and τ2 are characteristic decay times, and A1, A2 and v0 are constants. The two characteristic decay times are on the order of 10 μs and 500 μs. The relative contribution of the two decay times depends on the magnitude of the initial applied voltage pulse. We will describe preliminary results on the correlation between the OCVD and solar cell performance, including the effects of light-soaking on OCVD behavior.
Highly Mismatched Alloys for Intermediate Band Solar Cells
Authors: Walukiewicz W. , Yu K. M. , Wu J , Ager J. W. , Shan W. , Scrapulla M. A. , Dubon O. D. , Becla P. 
Published: November 2011

AbstractIt has long been recognized that the introduction of a narrow band of states in a semiconductor band gap could be used to achieve improved power conversion efficiency in semiconductor-based solar cells. The intermediate band would serve as a “stepping stone” for photons of different energy to excite electrons from the valence to the conduction band. An important advantage of this design is that it requires formation of only a single p-n junction, which is a crucial simplification in comparison to multijunction solar cells. A detailed balance analysis predicts a limiting efficiency of more than 50% for an optimized, single intermediate band solar cell. This is higher than the efficiency of an optimized two junction solar cell. Using ion beam implantation and pulsed laser melting we have synthesized Zn1-yMnyOxTe1-x alloys with x<0.03. These highly mismatched alloys have a unique electronic structure with a narrow oxygen-derived intermediate band. The width and the location of the band is described by the Band Anticrossing model and can be varied by controlling the oxygen content. This provides a unique opportunity to optimize the absorption of solar photons for best solar cell performance. We have carried out systematic studies of the effects of the intermediate band on the optical and electrical properties of Zn1-yMnyOxTe1-x alloys. We observe an extension of the photovoltaic response towards lower photon energies, which is a clear indication of optical transitions from the valence to the intermediate band.
Design of a window layer for flexible Cu(In,Ga)Se2 thin film solar cell devices
Authors: Kaufmann Christian A. , Neisser Axel , Klenk Reiner , Scheer Roland , Schock Hans-Werner 
Published: November 2011

AbstractFor laboratory scale devices the transfer of the Cu(In,Ga)Se2 (CIGSe) thin film technology from a rigid float glass substrate to flexible titanium foil is achieved. Here we will highlight the effect of the rough, flexible substrate on the electrical and optical characteristics of the transparent window layers of such devices. The roughness of the substrate may give rise to changes in sheet resistance of the transparent front contact and in the reflectivity of the completed device. However, the devices deposited onto the kind of titanium foil substrate used in this work are smooth enough not to affect the sheet resistance; nevertheless optical effects are enough to affect the process window for an antireflective coating. With the use of an antireflective coating, a maximum efficiency of 17.4% could be reached for 0.5 cm2 area devices on glass.
Understanding Aniline Surface Treatment of CdTe
Authors: Dobson Kevin D. , Einstein Stephanie A. , Sadowsky Daniel D. , McCandless Brian E. , Birkmire Robert W. 
Published: November 2011

AbstractSurface etching of CdTe under illumination in aqueous aniline-based solutions has been investigated. Analysis of treated samples shows the formation of crystalline Te on the CdTe surface. Analysis of bath and treatment conditions indicated the presence of aniline, Cl- ions, dissolved O2, consistent illumination and careful control of pH as critical for successful surface etching. A photocatalytic mechanism is proposed for the reaction, where CdTe is etched by H2O2 or similar, generated through reduction of dissolved O2 by conduction band electrons and complemented by oxidation of aniline. The generated Te is stable in the bath and the treatment provides reproducible surfaces. CdTe/CdS devices of 12% conversion efficiency were processed with 30 min aniline treatments. The toxicity of aniline is a concern and criteria for possible substitutes are discussed.
Development of a software platform for a plug-in hybrid electric vehicle simulator
Authors: Karlis Athanasios , Bibeau Eric , Zanetel Paul , Lye Zelon 
Published: November 2011

Abstract
Electricity use for transportation has had limited applications because of battery storage range issues, although many recent successful demonstrations of electric vehicles have been achieved. Renewable biofuels such as biodiesel and bioethanol also contribute only a small percentage of the overall energy mix for mobility. Recent advances in hybrid technologies have significantly increased vehicle efficiencies. More importantly, hybridization now allows a significant reduction in battery capacity requirements compared to pure electric vehicles, allowing electricity to be used in the overall energy mix in the transportation sector. This paper presents an effort made to develop a Plug-in Hybrid Electric Vehicle (PHEV) platform that can act as a comprehensive alternative energy vehicle simulator. Its goal is to help in solving the pressing needs of the transportation sector, both in terms of contributing data to aid policy decisions for reducing fossil fuel use, and to support research in this important area. The Simulator will allow analysing different vehicle configurations, and control strategies with regards to renewable and non-renewable fuel and electricity sources. The simulation platform models the fundamental aspects of PHEV components, that is, process control, heat transfer, chemical reactions, thermodynamics and fluid properties. The outcomes of the Simulator are: (i) determining the optimal combination of fuels and grid electricity use, (ii) performing greenhouse gas calculations based on emerging protocols being developed, and (iii) optimizing the efficient and proper use of renewable energy sources in a carbon constrained world.
Extracorporeal Shock Wave Treatment of Non- or Delayed Union of Proximal Metatarsal Fractures
Authors: Alvarez Richard G. , Cincere Brandon , Channappa Chandra , Langerman Richard , Schulte Robert , Jaakkola Juha , Melancon Keith , Shereff Michael , Lee Cross G. 
Published: November 2011

Background: Nonunion or delayed union of fractures in the proximal aspect of metatarsals 1 to 4 and Zone 2 of the fifth metatarsal were treated by high energy extracorporeal shock wave treatment (ESWT) to study the safety and efficacy of this method of treatment in a FDA study of the Ossatron device. Materials and Methods: In a prospective single-arm, multi-center study, 34 fractures were treated in 32 patients (two subjects had two independent fractures) with ESWT. All fractures were at least 10 (range, 10 to 833) weeks after injury, with a median of 23 weeks. ESWT application was conducted using a protocol totaling 2,000 shocks for a total energy application of approximately 0.22 to 0.51 mJ/mm2 per treatment. The mean ESWT application time for each of the treatments was 24.6 ± 16.6 minutes, and anesthesia time averaged 27.1 ± 10.4 minutes. All subjects were followed for 1 year after treatment at intervals of 12 weeks, 6, 9, and 12 months. Results: The overall success rate at the 12-week visit was 71% with low complications, significant pain improvement as well as improvement on the SF-36. The success/fail criteria was evaluated again at the 6- and 12-month followup, showing treatment success rates of 89% (23/26) and 90% (18/20), respectively. The most common adverse event was swelling in the foot, reported by five subjects (15.6%). Conclusion: High-energy ESWT appears to be effective and safe in patients for treatment of nonunion or a delayed healing of a proximal metatarsal, and in fifth metatarsal fractures in Zone 2. Level of Evidence: IV, Retrospective Case Series
Prospective Study of a Cementless, Mobile-Bearing, Third Generation Total Ankle Prosthesis
Authors: Schenk Katja , Lieske Sebastian , John Michael , Franke Konrad , Mouly Stéphane , Lizee Emmanuel , Neumann Wolfram 
Published: November 2011

Background: The SALTO total ankle prosthesis is a nonce-mented mobile bearing anatomic design characterized by dual Ti-HA coating. This study reviews our results with this prosthesis. Materials and Methods: Between 2001 and 2007, 413 consecutive SALTO prostheses were implanted in our institution in 215 women and 198 men, aged 57.1 ± 11.9 years. At the last visit, 401 implants (47% in the left ankle) were available with a mean followup of 29 (range, 1 to 84) months. Results: Based on the results of the 218 patients with at least 2 years of postoperative followup, the 5-year estimated survivorship, with the primary end-point being implant removal, was 86.6% and ranged from 85.1% in patients with post-traumatic osteoarthritis to 95.6% in those with rheumatoid arthritis. The AOFAS score increased from 50.9 ± 16.8 points preoperatively to 82.2 ± 14 points at followup (mean difference, 31. 1 ± 1.4, 95% confidence interval (C.I.) for the difference, 28. 3 to 33.8, p < 0.001). Visual analog scale for pain decreased from 7.4 ± 1.1 preoperatively to 2.0 ± 2.0 postoperatively (mean difference, −5.4 ± 0.7, 95% C.I. for the difference, −5.6 to −5.2, p < 0.001). Flexion/extension ROM increased from 25.2 ± 14.1 degrees to 33.1 ± 13.6 degrees at the last followup visit (mean difference, 7. 9 ± 0.5 degrees, 95% C.I. for the difference, 4. 3 to 7.2, p < 0.001), while pronation/supination ROM increased from 23.8 ± 13.7 degrees to 25.4 ± 14.5 degrees (mean difference, 1. 6 ± 0.7 degrees, 95% C.I. for the difference, 0. 9 to 2.2, p = 0.005). Conclusion: The SALTO prosthesis provided good clinical and functional results and we believe helps validate the concept of anatomic replacement. Level of Evidence: IV, Retrospective Case Series
Other side of the Ashulia wetland: a limnological purview
Authors: Hossain Bhuiyan M Azmal , Khondker Moniruzzaman , Begum ZN Tahmida 
Published: November 2011

Limnology of a temporary wetland Ashulia was found highly seasonal. Fluctuations of water depth, water temperature, Secchi depth, pH, conductivity, total dissolved solids, dissolved oxygen and alkalinity were studied in three different stations for one year. Water depth showed a range of 1.5 - 4.2 m and Secchi disc transparency from 0.07 - 2.15 m. Annual ranges in respect of pH, conductivity, total dissolved solids (TDS), dissolved oxygen (DO) and alkalinity of water varied from 6.3 -7.2, 92 - 1028 μS/cm,43.4 - 491.0 mg/l, 4.3 - 28.9 mg/l, and 0.71 - 6.45 meq/l, respectively. The wetland showed a good to moderate water quality during rainy season because in this season visibility of water increased, TDS load, alkalinity and conductivity came down to their lowest. Dissolved oxygen content also showed an acceptable water quality value during rainy season. Key words: Wetland; Physical factors; Chemical factors; Limnology; Phytoplankton; Macrophytes DOI: http://dx.doi.org/10.3329/dujbs.v19i1.8940 DUJBS 2010; 19(1): 21-26
Effects of water depth on the growth of nelumbo nucifera gaertn. Seedlings
Authors: Alfasane Md Almujaddade , Khondker Moniruzzaman , Begum ZN Tahmida 
Published: November 2011

Water depth showed significant effect on the growth of Nelumbo nucifera Gaertn. in deep and shallow water culture pits. In deep water culture pit, the leaf area showed its highest growth rate of 21.84 ± 2.89 cm2/day in summer and petiole length showed highest growth rate of 0.34 ± 0.10 cm/day in monsoon. The plantlets grown in shallow water culture pit showed highest growth rate of leaf area of 8.75 ± 0.91 cm2/day in summer and the length of the petiole was highest in monsoon (0.25 ± 0.03 cm/day). Comparatively highest growth was observed in deep water culture pit rather than that of shallow water. Highest growth of the plant and flowering were found to be associated with higher water depth (100 cm) where the plant grew up to a height of about 1.5 m and maximum leaf diameter was 50 cm. Poor growth of the plant with no flowering was in shallow water depth (20 cm) where maximum height of the plant was about 0.5 m and leaf diameter was 25 cm. Although the concentrations of NO3?N, soluble reactive phosphorus, soluble reactive silicate, planktonic chl a and phaeopigment were in higher amount in shallow water culture pit but due to shallow depthness plant showed poor growth and no flowering. Key words: Water depth; Limnological factors; Growth; Nelumbo nucifera DOI: http://dx.doi.org/10.3329/dujbs.v19i2.8952 DUJBS 2010; 19(2): 111-118
Reduced susceptibility to fluroquinolone and molecular analysis of ciprofloxacine resistance in salmonella typhi in Bangladesh
Authors: Sarker ABM Sarwer-E-Alom , Saha Samir K , Islam Maksuda , Hossain MA 
Published: November 2011

The study of the trend of infection, susceptibility to antibiotics and molecular level analysis of the cause of reduced susceptibility of Salmonella typhi isolates from the patients in Bangladesh were studied. Out of 9040 blood cultures obtained during the study period, 1266 (14.0%) showed significant growth. Nearly three?fourths of the positive blood cultures were due to S. typhi and rests were mostly of S. paratyphi A. The prevalence was highest between the age group 25 and 60 months. Male showed slightly higher rate of infection than female. Among all 943 S. typhi isolates, 42.6, 42 and 41.4% were sensitive to ampicillin, cotrimoxazol and chloramphenicol, respectively. All isolates were sensitive to ceftriaxon and ceftazidim; 9 isolates were ciprofloxacin resistant, others were moderate to highly sensitive; whereas, only 2.2% isolates were sensitive and almost all (97.8%) were found resistant to nalidixic acid. The E?strip test among 411 isolates showed the MIC value of 53 isolates nearer to the very sensitive (< 0.125 μg/ml), 252 isolates between 0.125 and 0.5 μg/ml, 95 isolates between 0.5 and 2.0 μg/ml and rest other 11 isolates showed from > 2.0 μg/ml to very highly resistant (512 μg/ml). VNTR pattern of all ciprofloxacine resistant S. typhi was also same. Restriction fragment analysis of gyrase?A gene indicated point mutations in different loci that bear the cause of being resistant to ciprofloxacin. Key words: Reduced susceptibility; Typhoid fever; Salmonella typhi; Fluoroquinolone DOI: http://dx.doi.org/10.3329/dujbs.v19i2.8955 DUJBS 2010; 19(2): 137-144
Bacterial load in twelve freshwater fishes of four feeding habits in Bangladesh
Authors: Rahman M Shamsur , Hasan Mahmud , Mahmud Zahid Hayat , Islam M Sirajul 
Published: November 2011

Homogenized samples of skin, gill and gut of twelve freshwater fishes of four feeding habits were used for bacteriological test. Total bacterial count (TBC), total coliform (TC), faecal coliform (FC), faecal streptococci (FS) and total Vibrio?like colonies were enumerated using serial dilution and spread plate techniques. Variation of bacterial loads among the fishes of various feeding habits was insignificant. The TBC, TC, FC, FS and total Vibrio counts ranged from 1.72 ± 0.68 × 108 to 7.00 ± 3.39 × 108, 2.49 ± 1.72 × 106 to 6.55 ± 3.00 × 106, 1.58 ± 1.29 × 106 to 2.76 ± 1.42 × 106, 4.83 ± 2.09 × 104 to 1.19 ± 0.46 × 105 and 2.06 ± 0.67 × 103 to 3.68 ± 2.02 × 105, respectively among various feeding groups. However, gill and gut had significantly higher density of TBC, TC and FC than that of the skin. High counts of indicator organisms indicate that market fishes of all varieties could be the potential reservoirs in transmission of pathogenic bacteria responsible for diarrhoeal disease. Key words: Bacterial load; Freshwater fishes; Feeding habit DOI: http://dx.doi.org/10.3329/dujbs.v19i2.8956 DUJBS 2010; 19(2): 145-150
Seasonal prevalence, intensity and organal distribution of Helminth parasites in macrognathus aculeatus
Authors: Khanum Hamida , Begum Salma , Begum Aleya 
Published: November 2011

Examination of 122 individuals of Macrognathus aculeatus (popularly known as Tara Baim), collected monthly, from the river Buriganga during March, 2007 to February, 2008 revealed 77 fishes were infected with various helminth parasites with an infection rate of 63.11% and intensity of infection of 3.18. A total of 245 parasites were recovered from different organs of the fishes, with the highest number from the intestine. Six species of helminths were detected, of which two were trematodes (Clinostomum piscidum and Rhynchooharynx paradoxa), one species of cestode (Marsipometra parva) and three species of nematodes (Pseudoproleptus vestibules, Cucullanus cirratus and Porrocaecum trichiuri L3 larva). The prevalence and intensity of parasitic infection were a bit higher in female fish than in male. The parasites were much more abundant in rainy season (75%) followed by summer (62.5%) and winter (31.81%). The larger fishes were heavily infected (71.01%) than medium (53.33%) and smaller (52.17%) fishes. Key words: Macrognathus aculeatus; Helminth; Prevalence; Intensity; Organal distribution; Seasonal variation DOI: http://dx.doi.org/10.3329/dujbs.v20i2.8971 DUJBS 2011; 20(2): 117-122