An Experimental Investigation on the Performance Enhancement of Photovoltaic/Thermal Panel Using a Tracking System and Nanofluid (Al 2O3)

This work presents an improving of the photovoltaic / thermal efficiency by using a solar tracking system (2-axes) and AL2O3 mixed with water as working fluid. An integrated system (PV/T) consists of 36 mono-crystalline solar cell was designed and implemented with cooling water technique utilized copper pipes on the back PV side to flow cooling water at different mass flow rates . A (90) bulbs of (12V, 50W) are connected in series are used to simulate the sun light and controled by (3) AC to AC transformers to give different irradiation arrive up to (1000 W/m2).The (AL2O3) was prepared and added to the water with different concentrations to decrease the temperature of PV and increase the rate of heat transfer to maintain good electrical efficiency and an increase in thermal efficiency.The experimental work has been conducted in (UMPEDAC) / Malaysia. The experimental results indicated that when using two- axes solar tracking system the output power generated was increased from (21.69W) to (30.69W). The power module generated is decreased when the temperature of PV surface increased from (64.05W at 24.7oC) to (39.46W at 79.1oC). It is proved that the temperature of PV surface is rising and that efficiency does not exceed 8%, if there is no water-cooling while under the influence of process cooling water, the efficiency increased to 9.6%. In addition, it founded that the optimum mass flow rat of water was (0.2) L/s. At using nanofluid (AL2O3-water) as a percentage ratios (0.1, 0.2, 0.3, 0.4, 0.5) % at constant mass flow rate (0.2) L/s, the temperature dropped significantly from (79.1oC) to (42.2oC). It is found that an optimum concentration ratio of nanofluid at 0.3% and the electrical efficiency of PV/T was 12.1% while the thermal efficiency was 34.4%

A single-step synthesis of nitrogen-doped graphene sheets decorated with cobalt hydroxide nanoflakes for the determination of dopamine

Nitrogen-doped reduced graphene oxide (NrGO) sheets decorated with Co(OH)2 nanoflakes were prepared by a single-step hydrothermal process. The morphological and structural characterizations of as synthesized NrGO@Co(OH)2 nanoflakes were performed by field emission scanning electron microscopy (FESEM), EDX-mapping and X-ray diffraction (XRD). NrGO@Co(OH)2 nanoflakes modified glassy carbon electrode (GCE) was used for electrochemical sensing of dopamine in neutral medium. The nanocomposite modified electrode showed enhanced electrochemical sensing ability for the detection of dopamine and the limit of detection (LoD) was found to be 0.201 μM with a sensitivity value of 0.0286 ± 0.002 mA mM−1. Interference studies revealed that NrGO@Co(OH)2─GCE endow excellent selectivity for DA detection even in the presence of higher concentration of common co-existing physiological interfering analytes. Additionally, proposed sensor demonstrated excellent performance in urine samples with promising reproducibility and stability

Implementation of a multicenter biobanking collaboration for next-generation sequencing-based biomarker discovery based on fresh frozen pretreatment tumor tissue biopsies

__Background__ The discovery of novel biomarkers that predict treatment response in advanced cancer patients requires acquisition of high-quality tumor samples. As cancer evolves over time, tissue is ideally obtained before the start of each treatment. Preferably, samples are freshly frozen to allow analysis by next-generation DNA/RNA sequencing (NGS) but also for making other emerging systematic techniques such as proteomics and metabolomics possible. Here, we describe the first 469 image-guided biopsies collected in a large coll