Detecting Fast Frequency Events in Power System: Development and Comparison of Two Methods

In power systems, frequency deviation from nominal value can occur due to reasons such as loss of generation, loss of load, or major faults in the grid. Such frequency fluctuations can lead to serious subsequent outages and damages to both end-user and utility equipment. Therefore, a proper frequency deviation detection methodology must be in place to effectively identify frequency events in a timely manner. This manuscript provides a comparative analysis between two frequency deviation detection algorithms. One is based on signal processing and statistical analysis. The other is a regression-based algorithm. Both of these algorithms have multiple adjustable parameters, making them highly tunable for different Balancing Authorities

Diuretic activity of carob (Ceratonia silique L.) Honey: comparison with furosemide

Background: Honey has wide range of biological activities. It has effect on renal function, and urinary nitric oxide and prostaglandins level. The present study was conducted to evaluate diuretic potential of carob honey, collected from Morocco, in normal rats and the results were compared with use of furosemide.Materials and methods: Adult male Wister rats weighing between 230 and 278 g were used. The animals were divided into three groups; group 1 received oral administration of distilled water (10 ml/kg BW), and served as control group, group 2 received oral administration of furosemide (10 mg/kg BW), and group 3 was treated with oral administration of carob honey (100 mg/kg BW). Urine volume, and urine and plasma sodium and potassium were measured after single dose of the interventions and after daily administrations of the interventions.Results: After the single dose of carob honey, urine output was significantly increased at all time intervals (1-6 hrs and at 24 hrs after administration). The daily dose of carob honey for nine days significantly increased urine volume as compared to control group. Carob honey increased urinary levels of sodium and potassium, and did not cause hypokalemia, while furosemide increased urinary sodium and potassium and caused hypokalemia.Conclusion: Carob honey has diuretic, natriuretic and kaliuretic activity without side effects of hypokalemia that was observed with use of furosemide.Key words: Carob honey, furosemide, diuresis, sodium, potassium, creatinine clearanc

Carbonaceous Materials Coated Carbon Fibre Reinforced Polymer Matrix Composites

Carbon fibre reinforced polymer composites have high mechanical properties that make them exemplary engineered materials to carry loads and stresses. Coupling fibre and matrix together require good understanding of not only fibre morphology but also matrix rheology. One way of having a strongly coupled fibre and matrix interface is to size the reinforcing fibres by means of micro- or nanocarbon materials coating on the fibre surface. Common coating materials used are carbon nanotubes and nanofibres and graphene, and more recently carbon black (colloidal particles of virtually pure elemental carbon) and graphite. There are several chemical, thermal, and electrochemical processes that are used for coating the carbonous materials onto a carbon fibre surface. Sizing of fibres provides higher interfacial adhesion between fibre and matrix and allows better fibre wetting by the surrounded matrix material. This review paper goes over numerous techniques that are used for engineering the interface between both fibre and matrix systems, which is eventually the key to better mechanical properties of the composite systems

The effect of thermal processing in oil on the macromolecular integrity and acrylamide formation from starch of three potato cultivars organically fertilized

Starches from three organically produced cultivars of potato tuber (Lady Rosetta, Spunta and Voyager) have been studied in relation to (i) acrylamide production (ii) macromolecular integrity after frying with extra virgin olive oil, soybean oil and corn oil. During cultivation, a treatment involving the combination of nitrogen, phosphorus and potassium fertilization under organic farming was applied (N1, P2, K1 where Ν1 = 1.3 g Ν per plant, P2 = 5.2 g P2O5 per plant, Κ1 = 4.0 g K2O per plant). Potatoes fried in olive oil retained the highest glucose concentrations for all cultivars 0.85 ± 0.2 mmol/kg, followed by 0.48 ± 0.2 for those fried in corn oil and 0.40 ± 0.1 mmol/kg for those fried in soybean oil. The highest average fructose concentration was recorded for the samples fried in corn oil as 0.81 ± 0.2, followed by 0.80 ± 0.2 and 0.68 ± 0.3 mmol/kg for the samples fried in olive and soybean oils, respectively. Asparagine was the most abundant free amino acid in the three varieties tested, followed by glutamine and aspartic acid. The mean initial concentration of asparagine in raw potatoes tubers was 42.8 ± 1.6 mmoles kg−1 for Lady Rosetta, 34.6 ± 1.2 mmoles kg−1 (dry weight) for Spunta and 36.2 ± 2.0 mmoles kg−1 for Voyager. Lady Rosetta contained a significantly higher concentration of asparagine compared to the other two varieties (p < 0.05). The greatest quantity of acrylamide was observed in French fries derived from the potato variety Lady Rosetta when fried in soybean oil and it was 2,600 ± 440 μg/kg, followed by Spunta which was 2,280 ± 340 μg/kg and Voyager 1,120 ± 220 μg/kg. There is a significant reduction in the formation of acrylamide in the variety Voyager compared to the others (p = 0.05)

Attitudes and Perceptions of Healthcare Providers towards Clinical Pharmacy Services at a Tertiary Care Hospital in Riyadh, Saudi Arabia

Purpose: To evaluate the attitudes and perceptions of health care providers towards clinical pharmacy services at King Khalid University Hospital Riyadh Saudi ArabiaMethod: A cross-sectional survey of healthcare providers was conducted in King Khalid University Hospital, Riyadh, Saudi Arabia from September to November 2013. A self-administered questionnaire was delivered to health care professionals (HCPs) who included physicians, pharmacists and nurses.Results: The response rate was 78 % (457/600). The majority of the respondents (92.4 %) knew that the clinical pharmacist is an integral part of the medical team while 86.5 % of the participants expressed confidence in the ability of clinical pharmacists to improve the quality of patient care through their practice. Despite the relative lack of awareness of the increasing interest in clinical pharmacy practice (59.6 % were not aware of such a trend), pharmacists were less appreciative (p &lt; 0.05) of the positive role of clinical  pharmacists in direct patient care compared to both physicians and nurses (67.4, 74.3 and 72.3 %, respectively).Conclusion: The findings of this study reveal that health care professionals HCPs have positive attitude towards the role of the clinical pharmacist in the health care setting studied. However, there is a need for Saudi hospitals to adopt full clinical pharmacy service including drug monitoring, drug information and pharmacotherapy for enhanced health care.Keywords: Saudi Arabia, Clinical pharmacy services, Healthcare professionals, Attitude, Patient car

Efficacy of self-designed intraoral appliances in prevention of cheek, lip and tongue bite after local anesthesia administration in pediatric patients

The occurrence of self-inflicted soft tissue injuries following administration of local anesthesia in pediatric patients who have received dental treatment has been reported. Aim: To evaluate the attitudes and knowledge regarding cheek, lip, and tongue bite post administration of local anesthesia among dental practitioners in Saudi Arabia. Additionally, the efficacies of three types of intraoral appliances on the prevention of self-harm were evaluated in pediatric patients. A total of 301 practitioners were provided with a questionnaire consisting of 9 items. In addition, three types of intraoral appliances made of polyethylene terephthalate were designed as follows: design 1 (consisted of an anterior extension with numerous perforations); design 2 (had a buccal flap extension); and design 3 (comprised of serrated borders). The appliances were placed in the oral cavities of 45 children (age, 3?15 years) immediately after the completion of the dental procedure. The patient was asked to retain the appliance for 3 h. After 24 h, both parents and children were required to respond to a checklist to evaluate the effectiveness the appliances. Almost half of the dental practitioners had never encountered self-inflicted soft tissue injury in children after local anesthesia administration. About 60% of the dentists were of the opinion that provision of adequate instructions after treatment could prevent the occurrence of lip, cheek, and tongue biting. Furthermore, among the three appliances used, design 1 was most well accepted. Intraoral appliances used in this study may be considered for use to prevent self-inflicted soft tissue trauma in children following administration of local anesthesia

Microscopic Characterization of Mineral Dissolution and Precipitation at Variable Salinity for Improved Oil Recovery in Carbonate Reservoirs

Aging of carbonate mineral surfaces in brines of variable salinity and crude oil leads to massive transformations of surface topography and chemical composition including the formation of mixed organic-inorganic interfacial layers. The response of these interfacial layers to variations in brine composition is responsible for local (chemical) wettability alteration and therefore becomes the main microscopic driver for improved oil recovery in low-salinity water flooding or SmartWater flooding. In this study, a new method was developed to directly visualize local nanoscale dissolution and (re)precipitation around the three-phase contact line on model calcite surfaces in the presence of crude oil and ambient brine upon aging. The sessile microscopic oil drops on calcite surfaces were exposed to brines of variable composition at room temperature (22 °C) and at elevated temperatures (95 °C) for up to 2 weeks. Brines ranged from hypersaline formation water to diluted high-salinity water, in part enriched with Mg2+ or SO42- ions. In situ optical and ex situ atomic force microscopy (AFM) imaging of the calcite surfaces was performed prior to and after aging, complemented by confocal Raman imaging. Optical images show that crude oil drops remained attached to the mineral surfaces throughout all aging procedures studied and displayed only occasional minor relaxations of their shape at elevated temperatures. Ex situ AFM images after calcite cleaning and drying displayed strong marks of the original droplet positions that appeared either as holes or as protruding mesas with respect to the surrounding surface level, with height differences up to several hundred nanometers. The sessile oil drops are thus found to protect the underlying calcite surface from both precipitation and dissolution, in overall agreement with the macroscopic calcite saturation of the brines. The qualitative trends are consistent for all conditions investigated, notwithstanding a higher degree of variability at elevated temperatures and upon preaging in oil-equilibrated formation water. In contrast to the calcite-brine interface that undergoes these massive transformations, the oil-calcite interface remains overall remarkably inert. Only at 95 °C does the occasional appearance of roundish rims accompanied by hillocks suggest the growth of water drops during aging, possibly via exchange across thin aqueous layers.</p

Aberrant right subclavian artery in a cadaver: a case report of an aortic arch anomaly

In early embryogenesis, aortic anomalies occur as a consequence of disorders in the development of the primitive aortic arches system. Aberrant right subclavian artery, also known as arteria lusoria, is one of the important congenital anomalies of the aortic arch, in which the right subclavian artery arises from the arch of aorta instead of the brachiocephalic trunk. During routine dissection of a female cadaver, we observed retro-oesophageal aberrant right subclavian artery arising as the fourth branch from the aortic arch. In this case, the brachiocephalic trunk was absent. Early detection of aortic arch anomalies through diagnostic interventions is helpful to avoid complications during surgical procedures

Poly(ethylene glycol) based nanotubes for tuneable drug delivery to glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most aggressive type of malignant brain tumour, which is associated with a poor two-year survival rate and a high rate of fatal recurrence near the original tumour. Focal/local drug delivery devices hold promise for improving therapeutic outcomes for GBM by increasing drug concentrations locally at the tumour site, or by facilitating the use of potent anti-cancer drugs that are poorly permeable across the blood brain barrier (BBB). For inoperable tumours, stereotactic delivery to the tumour necessitates the development of nanoscale/microscale injectable drug delivery devices. Herein we assess the ability of a novel class of polymer nanotube (based on poly(ethylene glycol) (PEG)) to load doxorubicin (a mainstay breast cancer therapeutic with poor BBB permeability) and release it slowly. The drug loading properties of the PEG nanotubes could be tuned by varying the degree of carboxylic acid functionalisation and hence the capacity of the nanotubes to electrostatically bind and load doxorubicin. 70% of the drug was released over the first seven days followed by sustained drug release for the remaining two weeks tested. Unloaded PEG nanotubes showed no toxicity to any of the cell types analysed, whereas doxorubicin loaded nanotubes decreased GBM cell viability (C6, U-87 and U-251) in a dose dependent manner in 2D in vitro culture. Finally, doxorubicin loaded PEG nanotubes significantly reduced the viability of in vitro 3D GBM models whilst unloaded nanotubes showed no cytotoxicity. Taken together, these findings show that polymer nanotubes could be used to deliver alternative anti-cancer drugs for local therapeutic strategies against brain cancers

Enhancing hydrogen generation through advanced power conditioning in renewable energy integration

Producing hydrogen using renewable energy is a pivotal move towards cleaner and eco-friendlier energy generation, playing a vital role in safeguarding the environment. This method merges power electronic tools with electrolysers, which are key in enhancing hydrogen creation efficiency. Given that electrolysis operate on direct current (DC) voltage, there's a need for DC-DC or AC-DC converters to guarantee the right voltage and current for optimal electrolysis. This study aims to present a power regulation system tailored for hydrogen production powered by renewable resources. This system consists of two main stages: the matrix converter and the 12-pulse diode rectifier. The matrix converter ensures a controlled intake of current from the alternating current (AC) side, leading to a sinusoidal output with limited harmonic disruption. Additionally, it produces an AC voltage with a controlled magnitude and frequency, designed to suit the 12-pulse diode rectifier that follows. This meticulous voltage control is fundamental, granting enhanced operational adaptability and producing a high-quality waveform to support the electrolysis. Finally, the 12-pulse diode rectifier's task is to transform the AC from the matrix converter into a consistent DC voltage, crucial for effective hydrogen production