Optimization approach for optical absorption in three-dimensional structures including solar cells

The rigorous coupled-wave approach (RCWA) and the differential evolution algorithm (DEA) were coupled in a practicable approach to maximize absorption in optical structures with three-dimensional morphology. As a model problem, optimal values of four geometric parameters and the bandgaps of three i-layers were found for an amorphous-silicon, multi-terminal, thin-film tandem solar cell comprising three p-i-n junctions with a metallic hexagonally corrugated back-reflector. When the optical short-circuit current density was chosen as the figure of merit to be maximized, only the bandgap of the topmost i-layer was significant and the remaining six parameters played minor roles. While this configuration would absorb light very well, it would have poor electrical performance. This is because the optimization problem allows for the thicknesses and bandgaps of the semiconductor layers to change. We therefore devised another figure of merit that takes into account bandgap changes by estimating the open-circuit voltage. The resulting configuration was found to be optimal with respect to all seven variable parameters. The RCWA+DEA optimization approach is applicable to other types of photovoltaic solar cells as well as optical absorbers, with the choice of the figure of merit being vital to a successful outcome.Comment: 14 pages, 5 figure

A domino reaction of tetrahalo- 7,7-dimethoxybicyclo[2.2.1]heptenyl alcohols leading to indenones and a de novo synthesis of ninhydrin derivatives

An efficient acid induced rearrangement of a tetrahalo-7,7-dimethoxybicyclo[2.2.1]heptenyl system leading to substituted indenones is reported. This domino reaction involves dehydration, olefin isomerization, ketal hydrolysis, [3,3]-sigmatropic rearrangement and dehydrohalogenation. The resultant vicinal dihalo olefin moiety in the efficiently generated indenone derivatives was utilized to transform into ninhydrin derivatives by employing Ru(III)-catalyzed oxidation

Quantitative infrared thermography resolved leakage current problem in cathodic protection system

Leakage current problem can happen in Cathodic Protection (CP) system installation. It could affect the performance of underground facilities such as piping, building structure, and earthing system. Worse can happen is rapid corrosion where disturbance to plant operation plus expensive maintenance cost. Occasionally, if it seems, tracing its root cause could be tedious. The traditional method called line current measurement is still valid effective. It involves isolating one by one of the affected underground structures. The recent methods are Close Interval Potential Survey and Pipeline Current Mapper were better and faster. On top of the mentioned method, there is a need to enhance further by synthesizing with the latest visual methods. Therefore, this paper describes research works on Infrared Thermography Quantitative (IRTQ) method as resolution of leakage current problem in CP system. The scope of study merely focuses on tracing the root cause of leakage current occurring at the CP system lube base oil plant. The results of experiment adherence to the hypothesis drawn. Consequently, res

On optical-absorption peaks in a nonhomogeneous thin-film solar cell with a two-dimensional periodically corrugated metallic backreflector

The rigorous coupled wave approach (RCWA) was implemented to investigate optical absorption in a triple-p-i-n-junction amorphous-silicon solar cell with a 2D metallic periodically corrugated backreflector (PCBR). Both total and useful absorptances were computed against the free-space wavelength $\lambda_o$ for both s- and p-polarized polarization states. The useful absorptance in each of the three p-i-n junctions was also computed for normal as well as oblique incidence. Furthermore, two canonical boundary-value problems were solved for the prediction of guided-wave modes (GWMs): surface-plasmon-polariton waves and waveguide modes. Use of the doubly periodic PCBR enhanced both useful and total absorptances in comparison to a planar backreflector. The predicted GWMs were correlated with the peaks of the total and useful absorptances. The excitation of GWMs was mostly confined to $\lambda_o < 700$ nm and enhanced absorption. As excitation of certain GWMs could be correlated with the total absorptance but not with the useful absorptance, the useful absorptance should be studied while devising light-trapping strategies.Comment: 17 pages; 8 figure

Synthesis of platencin core structures via twist-brendane

The formation of a twist-brendane via intramolecular enolate alkylation is described. Conversion of bicyclo[2.2.1]heptane scaffold present in this twist-brendane through a Grob-type fragmentation to unravel a functionalized bicyclo[2.2.2] system which contains all the necessary carbon atoms of the lipophilic core structure of nor -platencin, a platencin analogue is presented. Synthesis of core structure of platencin was also accomplished by extending this strategy to a starting material possessing a surrogate for the exocyclic methylene group

Pengaruh Adopsi Teknologi PHSL (Pemupukan Hara Spesifik Lokasi) Berbasis Pertanian Presisi terhadap Pendapatan Petani Padi di Desa Jembungan, Kabupaten Boyolali, Jawa Tengah

The highly increase of crop production in the future will be a compulsion and utilization of field will be more intensive. Therefore, precise pescription of crop fertilization is required. Site Specific Nutrient Management (SSNM) application is an innovative technology for rice farming through fertilization recommendation based on the principles of precision farming. The SSNM web-based application was developed by IRRI (International Rice Research Institute) in Philippines in collaboration with Agricultural Research &amp; Development Council (LITBANG Pertanian) .The aim of this research is to study the impact, paritcularly on farmers' income, in utilizing web-based version of SSNM. There was a significant differences in fertilization cost between the USAge of SSNM-based farming system and manual-based farming system.. The manual based fertilization cost is Rp 23,078. (12.93 % of total cost) whereas the SSNM-based fertilization cost is Rp 320,065 ( 20.62% of total cost. The application of SSNM was able to increase average rice production about 314.38 kg / hectare and thus farmers income raised to Rp 1,100,328 / hectare

Impact of laparoscopic versus open surgery on hospital costs for colon cancer: a population-based retrospective cohort study

OBJECTIVE: Laparoscopy is increasingly being used as an alternative to open surgery in the treatment of patients with colon cancer. The study objective is to estimate the difference in hospital costs between laparoscopic and open colon cancer surgery. DESIGN: Population-based retrospective cohort study. SETTINGS: All acute hospitals of the National Health System in England. POPULATION: A total of 55 358 patients aged 30 and over with a primary diagnosis of colon cancer admitted for planned (elective) open or laparoscopic major resection between April 2006 and March 2013. PRIMARY OUTCOMES: Inpatient hospital costs during index admission and after 30 and 90 days following the index admission. RESULTS: Propensity score matching was used to create comparable exposed and control groups. The hospital cost of an index admission was estimated to be £1933 (95% CI 1834 to 2027; p<0.01) lower among patients who underwent laparoscopic resection. After including the first unplanned readmission following index admission, laparoscopy was £2107 (95% CI 2000 to 2215; p<0.01) less expensive at 30 days and £2202 (95% CI 2092 to 2316; p<0.01) less expensive at 90 days. The difference in cost was explained by shorter hospital stay and lower readmission rates in patients undergoing minimal access surgery. The use of laparoscopic colon cancer surgery increased 4-fold between 2006 and 2012 resulting in a total cost saving in excess of £29.3 million for the National Health Service (NHS). CONCLUSIONS: Laparoscopy is associated with lower hospital costs than open surgery in elective patients with colon cancer suitable for both interventions

The Agent Pattern Driven Business Engineering (APBDE) approach enabled business-based systems

Agent design patterns form a new methodology used to improve the development of software agents. Agent design patterns can help by capturing solutions to common problems in agent design [Lange and Oshima, 1998].Agent design patterns are applied in different systems such as knowledge management systems, real-time systems, and network management systems. Agent design patterns for business-based systems, aim to support different ecommerce paradigms business-to-business (B2B) and business-to-consumer (B2C).In this paper, we developed an approach for extracting agent-based design patterns for B2C e-commerce to improve business-based processes.This approach is called an Agent Pattern Driven Business Engineering (APDBE).Based on this approach, we derived two agent-based commerce design patterns namely, the De-coupler Design Pattern (DecDP), and the Dynamic Design Pattern (DynDP). These design patterns are used to support selling/buying-based processes in e-commerce domain

Development of new all-optical signal regeneration technique

All-optical signal regeneration have been the active research area since last decade due to evolution of nonlinear optical signal processing. Existing all-optical signal regeneration techniques are agitated in producing low Bit Error Rate (BER) of 10-10 at below than -10 dBm power received. In this paper, a new all-optical signal regeneration technique is developed by using phase sensitive amplification and designed optical phase locked signal mechanism. The developed all-optical signal regeneration technique is tested for different 10 Gb/s Differential Phase Shift Keying degraded signals. It is determined that the designed all-optical signal regeneration technique is able to provide signal regeneration with noise mitigation for degraded signals. It is analyzed that overall, for all degraded test signals, average BER of 10-13 is achieved at received power of -14 dBm. The designed technique will be helpful to enhance the performance of existing signal regeneration systems in the presence of severe noise by providing minimum BER at low received power