Search

A high efficiency (> $$18\%$$ ) industrial large area crystalline silicon wafer solar cell fabrication process generally requires industrial equipment with large footprint, high capital and running costs. Stricter processing window, continuous monitoring and automated functioning are the reasons for it. However, for any conventional laboratory (lab) it is always difficult to manage these requirements with limited available lab space or insufficient fund and other related resources. In this work, we report a novel way to fabricate high efficiency full area aluminium back surface field monocrystalline silicon wafer solar cells in our lab using low-cost processing with small-footprint fabrication tools for 6 inch pseudo-square industrial wafers. The novelty of our work includes optimization of every fabrication process step, e.g., texturization, emitter diffusion, emitter passivation and anti-reflection coating deposition, edge-isolation, screen printing and co-firing individually. These modifications include tuning of processing tools and processes, utility changes and inclusion of additional process steps. Beaker-based chemical processes, manual diffusion furnace, introduction of low temperature oxidation, low temperature silicon nitride deposition processes, plasma-edge isolation tool, single manual screen printer, single oven drying of metal pastes and co-firing using rapid thermal processing tools were used at our lab. For our cells, actual and active area efficiencies of 18.5 and 19% (measured under AM1.5G 1 Sun condition), respectively, were achieved.

Synthesis, structure, optical absorption, emission and electroluminescence properties of a new blue emitting Al complex, namely, bis-(2-amino-8-hydroxyquinolinato), acetylacetonato Al(III) are reported. Multilayer OLED using the Al complex showed blue emission at 465 nm, maximum brightness of ∼ 425 cd/m2 and maximum current efficiency of 0.16 cd/A. Another multilayer OLED using the Al complex doped with phosphorescent Ir complex showed ‘white’ light emission, CIE coordinate (0.41, 0.35), maximum brightness of ∼ 970 cd/m2 and maximum current efficiency of 0.53 cd/A.

This paper presents a comparative prospective study of three modalities of surgical treatment for extrahepatic portal hypertension in children: central splenorenal shunt after splenectomy (CSS), side-to-side lienorenal shunt (SSLR) without splenectomy, and splenectomy and gastroesophageal devascularization (SGD). In an 18-month period, 27 procedures were performed: 10 CSS, 10 SSLR, and seven SGD. The outcomes were evaluated by fall in portal pressures, hematological parameters, shunt patency, splenic regression, and disappearance of esophageal varices. All three procedures were comparable in the fall of portal pressure after surgery. The average blood loss and operating time were statistically significant in favor of SSLR compared with CSS. At 3-month follow-up, shunt patency was confirmed by duplex Doppler study in all the patients in the SSLR group and in nine out of 10 patients in the CSS group. In the CSS and SGD groups, hypersplenism resolved in all the patients. In the SSLR group, blood counts improved in only five out of eight affected children. No patient re-bled during a follow-up of 3-5 years. There were no cases of hepatic encephalopathy or overwhelming postsplenectomy sepsis. In conclusion, CSS is useful when there is a large spleen, severe hypersplenism, and a shuntable splenic vein. SSLR is suitable when there is only mild splenomegaly, mild hypersplenism, and a shuntable splenic vein. Splenectomy and devascularization is the choice when there is no shuntable splenic vein.

A high divided sigmoid colostomy has been recommended for staged management of high anorectal malformation. We audited our cases of neonatal colostomy for high anorectal malformation to assess its effectiveness. A retrospective study was carried out of all surgical newborns admitted with high imperforate anus as the single diagnosis at our centre between December 1998 and December 2000. Morbidity and mortality were analysed after retrospective stratification into two groups (group A: birth weight2.5 kg; group B: birth weight2.5 kg). The chi square test was used to test the statistical significance in terms of outcome in the two groups. Overall mortality was 16%. Group A consisted of 34 babies: 30 with divided sigmoid colostomy and four with transverse loop colostomy. One baby with a divided sigmoid colostomy died from wound complications and septicaemia (mortality 2.9%). All four babies with transverse loop colostomy done under local anaesthesia survived, despite being sick on arrival. Group B consisted of 16 babies: 15 with sigmoid colostomy and one with transverse loop colostomy, with seven deaths (44%). None of the five babies with transverse loop colostomy done under local anaesthesia died, despite being sick on arrival, whereas all eight babies who died had undergone sigmoid colostomy under general anaesthesia. The difference in the outcomes of babies in groups A and B is highly significant ( p.01). Sick, small (2.5 kg) and septic babies arriving late to the unit do not appear to tolerate general anaesthesia and divided sigmoid colostomy well, despite that procedure's long-term advantages. Divided sigmoid colostomy has produced excellent results in babies2.5 kg, but in the context of the developing world and limited critical care availability, transverse loop colostomy under local anaesthesia may save lives.

A young girl with an uncommon renal tumour is the subject of this communication. A diagnosis of renal cell carcinoma was established post-operatively. Combined modality treatment including chemotherapy and radiotherapy has helped achieve a disease free survival of nearly 5 years.

The purpose of this study was to determine the major factors influencing the survival of babies with anorectal malformation (ARM) during the primary management in the neonatal period in a tertiary referral center. The outcome of 125 neonates with ARM, treated in a single hospital during a 2-year period, was analyzed retrospectively with particular reference to birth weight, time of arrival, and the type of ARM, including pouch colon and major associated anomalies, to see whether any of them had a significant effect on initial survival. High ARM (HARM) was present in 75, low ARM (LARM) in 36, and pouch colon in 14 babies. There were a total of 28 deaths (22%). In babies with isolated HARM weighing2.5 kg and brought to the hospital within the first 48 h of life, the survival was 100%, which dropped to 80% when brought later than 48 h. Of the babies with birth weight2.5 kg and isolated HARM but who were brought to the hospital within the first 48 h of life, 80% survived, whereas of those reaching the hospital after 48 h, only 55% survived. Two babies with pouch colon and two of the four babies with LARM and associated anomalies died. In the HARM group, of the 31 babies with major associated anomalies, only 37% with birth weight2.5 kg and 58% with birth weight2.5 kg survived. Low birth weight, major associated anomalies, and delay in referral were the three important factors that influenced the outcomes of babies with ARM during the neonatal period.

A $$2{\raise0.5ex\hbox{$\scriptstyle 1$}\kern-0.1em/\kern-0.15em\lower0.25ex\hbox{$\scriptstyle 2$}}$$ -year-old child with isolated complete transection of the common bile duct following a fall from a tractor was successfully managed by isolated jejunal loop interposition choledochoduodenostomy. The literature on isolated common bile duct injuries is reviewed.

In this paper, we show that the Meyer-Neldel rule can be satisfactorily explained by the temperature dependence of the fermi level. We argue that the universality of the Meyer-Neldel rule can be explained by the fact that the dangling bond is the dominant defect in amorphous silicon.

Most congenital tracheo-oesophageal fis fistulae are short; the purpose of this report is to describe an unusually long fistula. Despite its length, it had the usually encountered obliquity.

A Perforation of the right hepatic duct following blunt trauma to the abdomen was successfully repaired by an inlay pedicled flap of omentum 3 weeks after the injury.

Two patients with prolapse of an intususceptum through a perforation in the intussuscipiens are described. There was little peritonitis at exploration. Prolapse of an intussusceptum is an occasional operative finding in patients with perforated intussusception.

Perineal canal is an infrequently encountered female anorectal anomaly. The available surgical techniques for repair of this malformation are unsatisfactory because of their high risk of recurrence. We present a new surgical technique with posterior repositioning of the perineal canal in continuity with the anorectum. The advantages are a low risk of recurrence and excellent functional and cosmetic results.

Thirteen cases of psoas abscess were treated by surgical drainage through Petit's triangle. This underutilized anatomic space provides a simple and effective route for drainage of retroperitoneal abscesses.

Maternal anticonvulsant therapy during pregnancy may result in a coagulation defect in the neonate.

Pyloric atresia is a rare cause of vomiting in the newborn. In earlier reports excision of the membrane and Heineke-Mikulicz pyloroplasty have been advocated as the procedure of choice. We report the first attempt to preserve pyloric function by transgastric excision of the membrane in the treatment of this disorder.

Letter to the EditorSir,Renal and urological anomalies associated with Downsyndrome (DS) have been reported scantily and havereceived little attention from pediatricians and pediatricurologists. This association is not mentioned incomprehensive textbooks of pediatrics and pediatricurology. We encountered six patients of posterior urethralvalves (PUV) in association with Down syndrome wherethe diagnosis was delayed. Out of the 230 patients ofposterior urethral valves (PUV) in the follow up with theauthors, six patients had associated DS. Only one of thesewas picked up from the genetic clinic where over 500 DSpatients are registered. Rest of five patients were referreddirectly to Pediatric Urology services. The records ofthese patients were analyzed retrospectively. The age ofpresentation was between 1

Photoluminescence measurements on silicon implanted with boron, phosphorus, and dual implanted with phosphorus and boron are reported. A high intensity luminescence band between 0.9–1.03 eV is observed in the samples with dual implantation of boron and phosphorus. The luminescence band has similar spectral characteristics as that of the 1.018 eV W or II band which is observed in silicon samples irradiated with neutrons or ions. However the annealing behaviour of the luminescence band observed in our samples differs considerably from that of the W band, whose intensity increases on annealing at 525 K and is quenched on heating to 600 K. The luminescence band in our samples is not annealed out even at 900 C. The temperature dependence of the intensity of the luminescence band is also studied. It shows excitonic behaviour with an activation energy of 52 meV.