Copper (I) oxide (Cu2) based solar cells - a review

Copper (I) oxide (Cu2O) is a potential material for the fabrication of low cost solar cells for terrestrial application. A detailed survey on the previous work so far carried out on Cu2O based solar cells has been presented. The aspects discussed include the fabrication of Schottky (metal/semiconductor) barrier Cu2O solar cells, where different low work function metals are used to form the Schottky barrier solar cells. The problems associated with the Cu2O Schottky barrier solar cells and efforts made at improving the performance of these solar cells are highlighted. Discussions on heterojunction solar cells with Cu2O have also been presented. Various transparent conducting oxides (TCOs) used in forming the heterojunction cells are mentioned, and successes and failures of using them highlighted. The technological developments of these cells are still in their infancy and the performance remains very poor. The root causes of this poor performance are analyzed and possible areas for future research in the field are outlined. Keyword: Copper (I) oxide, Solar cells, Solar cells, Schottky barrier sola cell

Electroless deposition and electrical characterization of N- Cu2O layer

This work describes the preparation of n-Cu2O layer by the electroless methods of boiling and immersion of copper plates in 0.001M  CuSO4Electron Microscopy (SEM) have been used to characterize the oxide films deposited. XRD studies show, for the first time, that cuprous oxide (Cu2O) and cupric oxide (CuO) were deposited by the two methods. The dissolution of the oxide layer for boiling above the 60 minutes time was found to be due to the turbulent nature of the boiling solution. There was no dissolution of the oxide layer in the case of the immersion method. The thickness of the films deposited for 60 minutes boiling andthat obtained by the immersion method at the solution pH of 9.83 are approximately 4.8 ìm and 3.8ìm, respectively. The resistivities of the oxide layers were found to be 75.64 Ùcm and 61.32 Ùcm, respectively. Annealing of the sample for 60 minutes by boiling, changes the mixed oxides(Cu2O-CuO) into the single phase Cu2O.Keywords: n-Cu2O deposition, boiling and immersion methods

Phenotypic characteristics of local chickens in Dass and Tafawa Balewa local government areas of Bauchi State, Nigeria

The study was conducted in Dass and Tafawa Balewa local government areas of Bauchi State, between January and April 2018 to determine some characteristics of local chickens. A total of 400 matured chickens of mixed sex were used to determine the following morphometric traits; live weight (LW), wing span (WSP), body length (BL), girth circumference (GC) and shank length (SHL). Most of the birds available for the study were normal feathered (80.75 %), single combed (94.50 %), orange eyed (81.50 %), had white ear lobes (43.75 %), milky shanks (37.75 %) and red plumage (36.75 %), while the fewest types were frizzled (7.50 %), rose combed (5.50%), Brown eyed (2.50%), those with red ear lobes (22.75 %), ash shank (2.00 %), and blue plumage (1.00 %). Single combed (95.60%), orange eyed (84.10%) had white skin (98.60%) white ear lobe (44.50%), pink shank (36.00%) and red plumage (38.8%) and the fewest were rose combed (4.40%), brown eyed (1.10%), yellow skinned (1.40%), those with red ear lobe (22.31%), ash shanked (1.10%) and those with blue plumage (0.50%). Data generated on morphometric traits were analyzed using analysis of variance and Pearson’s correlation analysis was used in the estimation of relationships among the measurements (morphometric traits). The overall mean of 1.67 kg, 43.19 cm, 41.27 cm, 31.49 cm and 10.19 cm for LW, WSP, BL, GC and SHL were estimated. Sex had effect on all the parameters recorded. Males were significantly heavier than female (1.79 vs 1.55 kg; p<0.001) and had wider girth (p< 0.001), longer wings (p<0.05), body (p<0.01) and shank (p<0.05). Non-significant effect of location, genotype and qualitative body traits (comb type, plumage, eye, ear lobe and shank colours) were however observed on most parameters. The correlation coefficients among the morphometric traits were high, positive and significant indicating that they can predict each other specifically during selection. Keywords: Morphometric traits, Local chickens, Correlation and Selectio

Malaria vectors resistance to commonly used insecticides in the control of malaria in Bichi, northern Nigeria

This study was carried out in 2015 to assess the level of resistance of sibling species of Anopheles gambiae complex the principal malaria vector from Bichi in Kano state to three classes of insecticides; (DDT, Permethrin and Bendiocarb) approved by World Health Organization (WHO) for vector control with the aim of obtaining baseline susceptibility and resistance data by evaluating the potency of brands of insecticides used against the mosquito vector in the area where the disease is prevalent. An. gambiae larvae collected from ecologically contrasting breeding sites were reared to adults in the laboratory. Adults from the F1 progeny were assayed for resistance using the WHO adult insecticide susceptibility bioassay protocol. The mosquitoes were exposed to DDT, permethrin and bendiocarb belonging to 3 classes of insecticides. The individual sibling species were identified molecularly and the molecular resistance mechanisms characterized by SINE and kdr PCR methods respectively. The An. gambiae populations tested revealed high level of resistance to DDT and permethrin but less resistant to bendiocarb. Analysis of the genetic composition of the vector population revealed predominance of An. coluzzii (> 77%). L1014F and L1014S kdr mutations correlated to insecticide resistance phenotype expression. This study indicates differential distribution of the resistant genotype of Anopheles malaria vector between ecologically different habitats in the area. This insecticide resistance represents a threat to vector control tool and should be monitored. The information obtained could be useful in decision and planning making for vector control programs in the region.Keywords: Anopheles coluzzii, Anopheles gambiae, Insecticides, Malaria control, resistance, Susceptibilit

Plasma Blobs Observed by Ground-based Optical and Radio Techniques in the Brazilian Tropical Sector

Ground-based optical and radio observations were carried out in the tropical region in Brazil, during the period from October 1998 to September 2000, and on several occasions we detected F-region plasma blob (localized discrete plasma density enhancement) events. These are the first observations of blobs in the tropical F-region using combined ground-based optical and radio techniques. Allsky images were used to map the spatial extension and temporal location of plasma blobs and ionosonde and photometer measurements were used to measure the plasma densities. Interesting cases of plasma blob events were observed on October 07, 1999 and March 04, 2000 over Cachoeira Paulista (22.7S, 45.0W; magnetic latitude 13.25S, declination 20W), showing discrete plasma density enhancements near regions of plasma density depletion structures in the OI 630.0 nm emission images. In these two cases, the electron densities were enhanced by a factor of, approximately, 2 above the background level. In this paper we report the first ground-based observations of the plasma density enhancements, or blobs, and their association with equatorial spread-F plasma depletions, and suggest a possible mechanism for their generation

Loan Loss Provision and Earnings Management in Nigerian Deposit Money Banks

Researchers and financial economists have for long identified that bank managers use loan loss provisions which is a substantial accrual in the banking industry to manage reported earnings in line with the prediction of the agency theory. In Nigeria, this practice remains a mere theoretical insinuation because there are hardly any empirically documented evidences to support the assertion. In order to fill this void in literature, the present study explores the relationship between loan loss provision and earnings management in Nigerian DMBs. Secondary data were obtained from the 8 banks’ annual reports for the period of 2006 to 2011 and robust regression was used as a tool for data analysis. The result indicates that there is a positive relationship between the provision for loan losses and earnings management in Nigerian DMBs. It is therefore, recommended that, if emphasis is on the integrity of financial reports, regulators should put a ceiling on the provision for loan losses rather than leaving it at the total discretion of managers who provide it to suit their selfish interest. DOI: 10.5901/mjss.2014.v5n17p4

Mitigating the Event and Effect of Energy Holes in Multi-hop Wireless Sensor Networks Using an Ultra-Low Power Wake-up Receiver and an Energy Scheduling Technique

This research work presents an algorithm for extending network lifetime in multi-hop wireless sensor networks (WSN). WSNs face energy gap issues around sink nodes due to the transmission of large amounts of data through nearby sensor nodes. The limited power supply to the nodes limits the lifetime of the network, which makes energy efficiency crucial. Multi-hop communication has been proposed as an efficient strategy, but its power consumption remains a research challenge. In this study, an algorithm is developed to mitigate energy holes around the sink nodes by using a modified ultra-low-power wake-up receiver and an energy scheduling technique. Efficient power scheduling reduces the power consumption of the relay node, and when the residual power of the sensor node falls below a defined threshold, the power emitters charge the nodes to eliminate energy-hole problems. The modified wake-up receiver improves sensor sensitivity while staying within the micro-power budget. This study's simulations showed that the developed RF energy harvesting algorithm outperformed previous work, achieving a 30% improvement in average charged energy (AEC), a 0.41% improvement in average energy (AEH), an 8.39% improvement in the number of energy transmitters, an 8.59% improvement in throughput, and a 0.19 decrease in outage probability compared to the existing network lifetime enhancement of multi-hop wireless sensor networks by RF Energy Harvesting algorithm. Overall, the enhanced power efficiency technique significantly improves the performance of WSNs

Blood Biochemical Profile and Carcass Characteristics of Weaner Rabbits Fed Varying Inclusion Levels of Gamba Grass (Andropogon gayanus Kunth.) Forage

A study was conducted to investigate the effect of varying inclusion levels of Gamba grass (Andropogon gayanus Kunth) forage on haematological, blood biochemical and carcass characteristics of weaner rabbits. A total of 20 male rabbits of mixed breeds with an average initial weight of 450g were randomly assigned into four dietary treatments containing varying inclusion levels of gamba grass forage (0, 5, 10 and 15%). There were four rabbits per treatment, each serving as a replicate in a completely randomized design. Blood samples were collected at the end of eight (8) week feeding period before the carcass analysis.. Results indicated that there were significant (P<0.05) increasing trend in the haematological and blood biochemical parameters measured. There were 51% and 55% increases (P<0.05) in total protein (8.53 vs. 5.65g/dl) and calcium ions (2.65 vs. 1.18mmol/dl) in rabbits fed diet containing 15% inclusion level of gamba grass forage compared to the control. However, there were 10% and 17% decreases (P<0.05) in white blood cells (4.92 vs. 4.43%) and alkaline phosphate (89.33 vs. 76.33IU/dl) in rabbits fed the control diet than those fed diet containing 15% inclusion level of gamba grass. Also, there were 13% and 49% increase (P<0.05) in dressing percentage (54.80 vs. 48.60%) and weight of thigh (16.95 vs. 11.35%) in rabbits fed diet containing 15% inclusion level of gamba grass forage compared to the control. However, length of small intestine and weights of heart, head, stomach and small intestines were similar (P>0.05) across the treatments, respectively. It was concluded that gamba grass forage can be included up to 15% in the diet of weaner rabbits, without adverse effect on haematological, biochemical profile and carcass characteristics of the rabbits in Northern Guinea savanna of Nigeria. Gamba grass (Andropogon gayanus Kunth) forage can be included in the diets of weaner rabbits to reduce cost of production.Keywords: Blood, competition, carcass, feed, gamba, Nigeria, rabbi