Search

Duodenal inversum is a rare disease not frequently encountered in clinical practice. The diagnosis is usually made late due to its rarity. Many other causes of abdominal pain like ulcer disease, pancreatitis, malrotation are mostly thought of initially and the diagnosis is usually missed. Only a few cases of duodenal inversum present with outlet obstruction. Duodenojejunostomy is perhaps the ideal management for duodenal inversum if the patient presents with outlet obstruction. Our intention is to create awareness of such a rare disease with an available definitive treatment option in the form of minimally invasive surgery. One such case of a 31-year-old man is described that was successfully managed by laparoscopic duodenojejunostomy.

In most of the optoelectronics or photovoltaic based devices, different kinds of anti-reflection coatings on the substrate is mainly developed by sol-gel based coating process includes spin, dip and spray pyrolysis coatings. This paper enumerates in details regarding fabrication of thin films with its essential chemical procedures using sol-gel technique. Further it outlines about structural characterization and influences of physical and chemical parameters on the antireflection coatings prepare by sol-gel practice procedure. The essential coating on the substrate mainly depends on the heat treatment process, solution preparation and coating types using sol-gel application. The coated layer behaviour mainly relies on the ration of solvent to additive substances, concentration of taken precursor agent, and aging time of the solvent, thickness and substrate material of the coating. Among various coatings mainly anti-refection coating by sol-gel technique holds much attractiveness towards implementation due to its feasibility, low cost and compactness.

Transparent zinc sulfide (ZnS)-aluminium sulfide (Al2S3) composite thin-films are deposited on silicon solar cells through radio frequency (RF) sputtering method at room temperature to investigate the structural, optical, electrical, and thermal characteristics. X-ray diffraction analysis reveals the presence of the powder sample (ZnS-Al2S3) and its average crystallite size is 15.83 nm. The minimum electrical resistivity (ρ), maximum hall mobility (μ), and carrier concentration (N) of ZnS-Al2S3 nano-layer coated solar cells are measured to be 2.98 × 10−3 Ω cm, 14.89 cm2 V−1 s−1 and 24.88 × 1020 cm−3 respectively. For a time period of 25 min, ZnS-Al2S3 nano-layer sputter coating produces the maximum power conversion efficiencies (PCE) of 19.38% and 21%, obtained at open and controlled atmospheric conditions, respectively. The influence of operating temperature at both these open and controlled atmospheric conditions for ZnS-Al2S3 nano-layer coated silicon solar cells is observed. The ZnS-Al2S3 composite demonstrates the properties of a desirable anti-reflection coating material for enhancing the PCE of solar cells.

Current research has concentrated on the development of ZnAl2O4 (gahnite) spinel nanostructure through anti-reflection coating (ARC) material for improved power conversion efficiency (PCE) of polycrystalline silicon solar cells. Radio frequency magnetron sputtering technique was adopted to deposit transparent polycrystalline gahnite nano-microfilms at room temperature. Material deposition was performed in a pure argon atmosphere on polycrystalline silicon solar cell substrates with a coating duration of 5–45 min. The influence of gahnite spinel nanostructure-integrated coating on the efficiency of silicon solar cell was explored by investigating physical, electrical, optical characteristics and temperature distribution profiles. The synthesized ARC material has gahnite spinel crystal structure composed of two-dimensional (2D) nanosheets. Atomic force microscopy study revealed that the thickness of synthesized gahnite 2D nanosheets was about 50 nm. The resistivity of gahnite coated with the time duration of 35 (T-IV) minutes on silicon solar cell was measured to be 1.93 × 10−3 Ω cm. The nano-microfilms showed a great optical transmittance (97%) in the wavelength range of 300–800 nm. The maximum PCE of 21.27% at open atmospheric condition and 23.83% at controlled atmospheric condition had been achieved for 35 (T-IV) minutes of gahnite nano-microfilm coating and it has been proved that gahnite nano-microfilms assists the absorption of more photons on a polycrystalline silicon solar cell substrate. The results acquired indicate that the gahnite nano-microfilm is an appropriate ARC material for polycrystalline silicon solar cells to enhance the PCE.

The present research is focused on developing ZnAl2O4 (gahnite) spinel as an antireflection coating material for enhanced energy conversion of polycrystalline silicon solar cells (PSSC). ZnAl2O4 has been synthesized using dual precursors, namely aluminum nitrate nonahydrate and zinc nitrate hexahydrate in ethanol media. Diethanolamine has been used as a sol stabilizer in sol-gel process for ZnAl2O4 nanosheet fabrication. ZnAl2O4 nanosheet was deposited layer-by-layer (LBL) on PSSC by spin coating method. The effect of ZnAl2O4 coating on the physical, electrical, optical properties and temperature distribution in PSSC was investigated. The synthesized antireflection coating (ARC) material bears gahnite (ZnAl2O4) spinel crystal structure composed of two dimensional (2D) nanosheets. An increase in layer thickness proves the LBL deposition of ARC on the PSSC substrate. The ZnAl2O4 2D nanosheet comprising ARC on the PSSC was tested and it exhibited a maximum of 93 % transmittance, short-circuit photocurrent of 42.364 mA/cm2 and maximum power conversion efficiency (PCE) 23.42 % at a low cell temperature (50.2 °C) for three-layer ARC, while the reference cell exhibited 33.518 mA/cm2, 15.74 % and 59.1 °C, respectively. Based on the results, ZnAl2O4 2D nanosheets have been proven as an appropriate ARC material for increasing the PCE of PSSC.

The current scenario illustrates distinct interest in developing renewable energy sources for power generation. In this regard, several researches are performed in enhancing the power conversion efficiency of solar cells. The present work focuses on utilizing ZnAl2O4 (gahnite) spinel as antireflection coating material to improve the power conversion efficiency of silicon solar cells. Gahnite was synthesized using two precursors namely zinc nitrate hexahydrate and aluminum nitrate nonahydrate through sol–gel technique. The thickness of the prepared gahnite sheets measured through atomic force microscopy was around 50 nm. Single to quintuple layers of gahnite was deposited on silicon solar substrate using spin coating technique. The influence of gahnite coating on the structural, optical, electrical properties and cell temperature of silicon solar cells are analyzed. The synthesized gahnite bears spinel crystal structure in the form of two dimensional nanosheet. Increment in layer thickness proves the deposition of single to quintuple layer on silicon substrate. A maximum of 93% transmittance and 20.72% power conversion efficiency at a low cell temperature (39.4 °C) has been achieved for triple layer deposition proving diffusion of more photons on the substrate. The obtained results prove gahnite as suitable anti-reflection coating material for enhancing the power conversion efficiency of silicon solar cells.