A review of thermoelectric ZnO nanostructured ceramics for energy recovery

The thermoelectric devices have the ability to convert heat energy into electrical energy without required moving components, having good reliability however their performance depends on material selections. The advances in the development of thermoelectric materials have highlighted to increase the technology's energy efficiency and waste heat recovery potential at elevated temperatures. The fabrication of these thermoelectric materials depends on the type of these materials and the properties using to evaluate these kind of materials such as thermopower (Seebeck effect), electrical and thermal conductivities. Ceramic thermoelectric materials have attracted increased attention as an alternative approach to traditional thermoelectric materials. From these important thermoelectric ceramic materials that can be a candidate for n-type is ZnO doping, which have excellent thermal and chemical stability, as they are promising for high temperature power generator. This review is an effort to study the thermoelectric properties and elements doping related with zinc oxide nanoceramic materials. Effective ZnO dopants and doping strategies to achieve high electrical and thermal conductivities and high carrier concentration are highlighted in this review to enable the advanced zinc oxide applications in thermoelectric power generation

Investigation on microstructure and electrical properties of Bi doping Ca3Co4O9 nanoparticles synthesized by solgel process

In this study, nanoparticles of Bi doped Ca3-xCo4O9 [Ca3-xBixCo4O9 where x=0, 0.2, 0.4 and 0.6] were prepared by sol gel combustion method. The phase structures and microstructures of Bi doped Ca3-xCo4O9 powders preparation were investigated. The microstructural observations of different Bi doped Ca3-xCo4O9 powders were evaluated using X-ray diffraction analysis (XRD) and Variable Pressure Scanning Electron Microscope (VPSEM). The bulk Ca3-xBixCo4O9 samples were fabricated using uniaxial cold pressing technique. Electrical resistivity of bulk Ca3-xBixCo4O9 samples with different doping was measured using fourprobe method from 300 to 700°K. The electrical resistivity was found to decrease with increasing temperature for the bulk Ca3-xBixCo4O9 samples. The electrical properties of Ca3-xBixCo4O9 are non-monotonic functions of x

Correlation of Total Cholesterol and Glucose in Serum of Iraqi Patients with Atherosclerosis and Diabetes Mellitus Type 2

Cholesterol is a fatty substance (lipid) classified as a waxy steroid of fat. It is absorbed by the intestine into blood stream and is packaged inside a protein coat a chylomicron. Blood glucose is a simple monosaccharide absorbed directly into the blood stream during digestion. The level of blood glucose normally represents a balance between the inflow of glucose into blood and it is uptake by the tissue. Atherosclerosis is a general term for a number of different medical conditions that affect the heart, this is occurs when the blood supply to a part of heart is interrupted, must commonly due to plaque, is build up in the coronary arteries consist of lipid cholesterol and calcium. It causes a damage of potential disease of heart muscle due to thickening and hardening of arteries. Diabetes mellitus is a disorder in which the level of blood glucose is persistently elevated above the normal range due to decrease secretion of insulin. The main objective of this study is to determine the concentrations of total cholesterol and glucose into blood serum of Iraq patients with atherosclerosis and diabetes mellitus type 2. This study included 60 specimens of patients with atherosclerosis and 60 patients with type 2 diabetes mellitus; their age range was 45-65 years. These patients were then matched by age and sex to 30 healthy individuals. Results revealed that there was highly significantly increased in the mean value of total cholesterol and glucose concentrations in patients of atherosclerosis (p<0.001) and diabetes mellitus (p<0.001) as compared with healthy individuals

First Record of Isolation and Characterization of Methicillin Resistant Staphylococcus lugdunensis from Clinical Samples in Iraq

This study was conducted to determine the frequency of Staphylococcus lugdunensis in different clinical samples. Out of 690 clinical samples, a total of 178 coagulase negative staphylococci (CoNS) isolates were recovered. CoNS were identified as 10 different species; 22 isolates belonged to Staphylococcus lugdunensis. Two specific genes for S. lugdunensis were used ( tanA gene and fbl gene) to confirm identification. Both of these specific genes were detected in 15 (68.1%) of 22 isolates that were identified phenotypically. The results of oxacillin MIC showed that 7 of the 15 (46.6%) S. lugdunensis isolates were oxacillin resistant. The antibiotic susceptibility testing against 16 antibiotics showed that resistance rates were variable towards these antibiotics. Eight of fifteen S. lugdunensis isolates (53.3%) were β-lactamase producer. Results of molecular detection of mecA gene found that mecA gene was detected in 6 (40%) of 15 S. lugdunensis. All of these 6 isolates (S1, S2, S3, S4, S5, and S6) were resistant to oxacillin. One isolate (S7) was resistant to oxacillin but mecA was not detected in this isolate. This study is a first record of isolation and characterization of methicillin resistant S. lugdunensis (MRSL) from clinical samples in Iraq