Secure High DER Penetration Power Distribution Via Autonomously Coordinated Volt/VAR Control

Traditionally voltage control in distribution power system (DPS) is performed through voltage regulating devices (VRDs) including on load tap changers (OLTCs), step voltage regulators (SVRs), and switched capacitor banks (SCBs). The recent IEEE 1547-2018 from March 2018 requires inverter fed distributed energy resources (DERs) to contribute reactive power to support the grid voltage. To accommodate VAR from DERs, well-organized control algorithm is required to use in this mode to avoid grid oscillations and unintended switching operations of VRDs. This paper presents two voltage control strategies (i) static voltage control considering voltage-reactive power mode (IEEE 1547-2018), (ii) dynamic and extensive voltage control with maximum utilization of DER capacity and system stability. Further, effective time-graded control is implemented between VRDs and DER units to reduce the simultaneous and negative operation. The proposed voltage control strategies are tested in a realistic 140-bus southern California distribution power system through extensive time-domain simulation studies. The results show that voltage quality in a distribution system is effectively achieved through the proposed voltage control strategies with a significantly reduction in the number of switching operations of VRDs. In addition, proposed voltage control strategies increase reliability and security of the DPS during unexpected failures

Why teach “Bioethics and Human Rights” to healthcare professions undergraduates?

This article highlights the importance of teaching “bioethics and human rights” to undergraduate students seeking health care degrees and illustrates how this topic fits well within these programs of studies. Historical, cultural, anthropological and practical reasons support teaching these topics as enrichment of medical training. The years after the Second World War showed how bioethics, human rights and medicine are closely intertwined. Moreover the relationship between human rights and bioethics has grown ever closer increasingly involving medicine and health care professionals. The authors observe that medical students have to face a cultural pluralism in bioethics and biolaw and we give students the opportunity to develop their critical thinking and logical argumentation abilities as well as their interest in academic research. Furthermore, the authors – who draw up briefly the experience of the Institute of Bioethics at the Faculty of Medicine and Surgery of the UCSC (Rome) - assert the necessity to help medical students to be respectful of patients in every clinical setting. It is therefore of utmost importance to train students to focus on the ethical dimension of care and to make good ethical decisions even in dilemmatic cases. To achieve this outcome, healthcare professionals should possess an integral vision of their work (technical and humanistic competence) and sharp skills to reflect in depth, avoiding superficiality and negligence. From this perspective, the teaching of “bioethics and human rights” could be very useful

Optimization and characterization of a new lipopeptide biosurfactant produced by marine Brevibacterium aureum MSA 13 in solid state culture

The biosurfactant production of a marine actinobacterium Brevibacterium aureum MSA 13 was optimized using industrial and agroindustrial solid waste residues as substrates in solid state culture

Solution-processable 2,1,3-benzothiadiazole containing compound based on the novel 1-dodecyl-6-dodecoxynaphthyridine-2-one unit for organic field-effect transistors

Small molecule organic semiconductors have well-defined structures and can be used in place of polymers which often show batch-to-batch variation. Many different electron-rich donor and electron-deficient acceptor units have been used to design materials with reduced HOMO-LUMO gaps and improved mobilities. Here we introduce a novel acceptor unit, 1-dodecyl-6-dodecoxynaphthyridine-2-one. This acceptor unit has been used in the synthesis of two novel compounds, with thiophene and 2,1,3-benzothiadiazole (BT) cores. The BT-containing compound shows a narrower HOMO-LUMO gap, broad solid-state absorption and has been applied to organic field-effect transistors, showing a mobility of 0.022 cm2 V−1 s−1 after optimisation of devices using self-assembled monolayers

Colorectal cancer survival rates in Ghana: A retrospective hospital-based study

BACKGROUND: Colorectal cancer (CRC) is one of the commonest cancers associated with diverse prognosis times in different parts of the world. Despite medical interventions, the overall clinical outcomes and survival remains very poor for most patients in developing countries. This study therefore investigated the survival rate of colorectal cancer and its prognostic factors among patients at Komfo Anokye Teaching Hospital, Ghana. METHODOLOGY: In this retrospective cohort study, a total of 221 patients diagnosed with CRC from 2009 to 2015 at the Surgical and Oncological units of Komfo Anokye Teaching Hospital (KATH), Kumasi, Ghana were employed. The survival graphs were obtained using the Kaplan-Meier method and compared by the Log-rank test. Cox regression analysis was used to assess prognostic factors. All analyses were performed by SPSS version 22. RESULTS: The median survival time was 15 months 95% CI (11.79-18.21). The overall survival rate for CRC over the 5 years period was 16.0%. The survival rates at the 1st, 2nd, 3rd, 4th and 5th years were 64% 95% CI (56.2-71.1), 40% 95% CI (32.2-50.1), 21% 95% CI (11.4-30.6) 16% 95% CI (8.9-26.9) and 16% 95% CI (7.3-24.9). There was a significant difference in the survival rate of colorectal cancer according to the different stages (p = 0.0001). Family history [HR = (3.44), p = 0.029)], Chemotherapy [HR = (0.23), p = CONCLUSION: The study has clearly demonstrated that survival rate for CRC patients at KATH, Ghana is very low in a 5 years period. This is influenced by significant number of clinical and pathological prognostic factors. Identification of prognostic factors would be a primary basis for early prediction and treatment of patients with colorectal cancer

Effect of end group functionalisation of small molecules featuring the fluorene-thiophene-benzothiadiazole motif as emitters in solution-processed red and orange organic light-emitting diodes

A series of red fluorescent materials (compounds 1-4), which each contain the symmetric fluorene-thiophene-BT-thiophene-fluorene core, is presented along with their performance in solution-processed OLED devices. Extending the molecular conjugation through end-capping with additional fluorene units (compound 2), or through incorporation of donor functionalities (compounds 3 and 4) improves OLED performance relative to the parent compound 1. Notably, incorporating triphenylamine donor groups in compound 3 led to solution-processed OLED devices operating with a peak luminance of 2888 cd m −2 and a low turn-on voltage (3.6 V)

Nanoparticles of Cu2ZnSnS4 as performance enhancing additives for organic field-effect transistors

The addition of oleylamine coated Cu2ZnSnS4 (CZTS) nanoparticles to solutions of an organic semiconductor used to fabricate organic field-effect transistors (OFETs) has been investigated. The oligothiophene-based small molecule 5T-TTF and the polymer poly(3-hexylthiophene) (P3HT) were each applied in the transistors with various concentrations of CZTS (5-20%). Atomic force microscopy (AFM) was applied to characterise the surface morphology of the OFETs. The use of 5 and 10 wt% of the CZTS nanoparticles in 5T-TTF and P3HT solutions, respectively, appears to be a simple and effective way of improving OFET performance

Correction: Nanoparticles of Cu2ZnSnS4 as performance enhancing additives for organic field-effect transistors

Correction for 'Nanoparticles of Cu2ZnSnS4 as performance enhancing additives for organic field-effect transistors' by Punarja Kevin et al., J. Mater. Chem. C, 2016, DOI: 10.1039/c6tc01650b

Thiazole-induced rigidification in substituted dithieno-tetrathiafulvalene : the effect of planarisation on charge transport properties

Two novel tetrathiafulvalene (TTF) containing compounds 1 and 2 have been synthesised via a four-fold Stille coupling between a tetrabromo-dithienoTTF 5 and stannylated thiophene 6 or thiazole 4. The optical and electrochemical properties of compounds 1 and 2 have been measured by UV-vis spectroscopy and cyclic voltammetry and the results compared with density functional theory (DFT) calculations to confirm the observed properties. Organic field effect transistor (OFET) devices fabricated from 1 and 2 demonstrated that the substitution of thiophene units for thiazoles was found to increase the observed charge transport, which is attributed to induced planarity through S-N interactions of adjacent thiazole nitrogen atoms and TTF sulfur atoms and better packing in the bulk