Evaluation the effectiveness of a non-chopped basalt fiber and water-based of isocyanate-polyester polyol prepolymer on the properties of cement fiberboard

Abstract Cement board reinforced with basalt fibers were prepared by using polymer compounds, 5% of water-based of isocyanate-polyester polyol prepolymer blend was used as a fixed percentage, and the rates of basalt fıber used were 5%, 7.5%, 10%, 12.5%, and for each of them used water/cement ratios (W/C) as 1.4, 1, 0.75, 0.4, and 0.5 respectively. The sample cured for 28 days, and the mechanical and physical properties of cement fiberboard were greatly improved due to additional fibers in cement compounds, the tests procedures of properties were carried out according to ASTM standard c-1185. It results reveals that 12.5% is the best percentage, in bending resistance, water absorption percentage, and the moisture content have improved, but it showed less thermal conductivity compared to other ratios, furthermore the compressive strength was improved. It is essential to indicate when increasing the polymer ratio, leads to a certain decrease in mechanical properties but improves the wetting surface of the basalt fibers and adhesion to cement. Therefore, a 5% polymers ratio chooses and the basalt fıber mix proportions changed to enhance the mechanical and physical properties of fiber boar

Dielectric Properties and AC conductivity of (Epoxy / Ion exchange) blend

The dielectric behavior of blend materials epoxy resin- Polyvinyl benzyl dimethyl ethanol ammonium chloride (PBDEAC) (Ion exchange) was analysed as a function of Ion exchange  weight content; temperature and frequency. Blends were prepared by mixing the components and pouring them into suitable moulds. The dielectric parameters have been measured using parallel plate capacitor method in the frequency range from 120 Hz to 2 MHz and in the temperature range from 30 ?C to 110?C. Variations of real (??) and imaginary (?") parts of dielectric constants and loss tangent of material with frequency and temperature have been studied. The experimental results showed that (??) and (?") increased with the addition of Ion exchange filler content. The value of (??) decreased with increasing frequency, which indicates that the major contribution to the polarization comes from orientation polarization. Dielectric loss peaks were also observed in the composite materials at high temperature. The value of (??) increased with increasing temperature, and is due to greater freedom of movement of the dipole molecular chains within the polymer at high temperature. Ac. conductivity and impedance of the composites behaviours as function of frequency and temperature have also been investigated. Keywords: Dielectric properties, epoxy, Ion exchange, ac. conductivity

Enhancement efficiency of polymer solar cells by incorporating metal oxide nanoparticles

Gold nanoparticles (AuNPs) deposited at the interface of the hole-collecting buffer layer [poly(3,4ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)] and regiore-gular poly (3-hexylthiophene) :[6,6]-phenylC61-butyricacidmethylester(rr-P3HT):(PCBM) active layer were found to significantly increase solar cell performance. The photo-physical properties of these devices incorporated with AuNPs with different space distributions in the interface of PEDOT:PSS buffer layer and P3HT:PCBM active layer are investigated. We find that, the optical property is improved as the AuNPs are large enough to penetrate into the active layer and the performance of Photovoltaic solar cells (PSCs) with large AuNPs can benefit from the improved hole collection efficiency. The efficiency enhancement for the device with a PEDOT:PSS: AuNPs film is more significant than for the device with PEDOT:PSS film. Keywords: PEDOT:PSS, Buffer layer, P3HT:PCBM, Gold oxide nanoparticle

Air cavity-based vibrational piezoelectric energy harvesters

Introduction. Known vibrational energy harvesting methods use a source of vibration to harvest electric energy. Piezoelectric material works as a sensing element converted mechanical energy (vibration) to electrical energy (electric field). The existing piezoelectric energy harvesting (PEHs) devices have low sensitivity, low energy conversion, and low bandwidth. The novelty of the proposed work consists of the design of PEH’s structure. Air cavity was implemented in the design where it is located under the sensing membrane to improve sensitivity. Another novelty is also consisting in the design structure where the flexural membrane was located at the top of electrodes. The third novelty is a new design structure of printed circuit board (PCB). The purpose of improvised design is to increase the stress in between the edges of PEH and increase energy conversion. With the new structure of PCB, it will work as a substrate that absorbs surrounding vibration energy and transfers it to sensing element. Methods. Three techniques were successfully designed in PEH and fabricated namely PEH A, PEH B, and PEH C were characterized by two experiments: load and vibration. The load experiment measured load pressure towards the PEH, whereas the vibration experiment measured stress towards the PEH. Results. PEH C has the highest induced voltage for a weight of 5.2 kg at the frequency of 50 Hz and the highest stored voltage for a period of 4 min. The three techniques applied in PEHs were showed improvement in transducer sensitivity and energy conversion. Practical value. A piezoelectric acoustic generator was used in the experiment to compare the performance of the designed PEH with available piezoelectric transducers in the market. The new flexible membrane worked as a sensing element was worked as a cantilever beam. PVDF was used as a sensing element due to the flexibility of the polymer material, which is expected to improve sensitivity and operating bandwidth.Вступ. Відомі методи збору вібраційної енергії використовують джерело вібрації для збору електричної енергії. П’єзоелектричний матеріал працює як чутливий елемент, перетворюючи механічну енергію (вібрацію) в електричну енергію (електричне поле). Існуючі пристрої збору п’єзоелектричної енергії (ЗПЕ) мають низьку чутливість, низьке перетворення енергії і малу смугу пропускання. Новизна запропонованої роботи полягає в проектуванні конструкції ЗПЕ. У конструкції реалізована повітряна порожнина, яка розташована під чутливої мембраною для підвищення чутливості. Ще один елемент новизни полягає в конструкції, в якій вигиниста мембрана розташована у верхній частині електродів. Третя новизна - це нова конструкція друкованої плати. Мета запропонованої конструкції - збільшити механічну напругу між краями ЗПЕ і підвищити перетворення енергії. Завдяки новій конструкції друкованої плати вона буде працювати як підкладка, яка поглинає навколишню енергію вібрації і передає її на чутливий елемент. Методи. Три методи були успішно використані для проектування ЗПЕ,  і відповідно названі виготовлені ЗПЕ A, ЗПЕ Б і ЗПЕ В були описані двома експериментальними характеристиками: навантаження і вібрація. В експерименті з навантаженням вимірювався тиск навантаження на ЗПЕ, в той час як в експерименті з вібрацією вимірювалася механічна напруга на ЗПЕ. Результати. ЗПЕ В має найвищу індуковану напругу для ваги 5,2 кг при частоті 50 Гц і найвищу збережену напругу протягом 4 хвилин. Три методи, що застосовуються для ЗПЕ, показали поліпшення чутливості перетворювача і перетворення енергії. Практична цінність. В експерименті використовувався п’єзоелектричний акустичний генератор для порівняння характеристик розробленого ЗПЕ з доступними на ринку п’єзоелектричними перетворювачами. Нова гнучка мембрана працювала як чутливий елемент, що представляв собою консольну балка. В якості чутливого елемента використовувався полівініліден фторид завдяки гнучкості полімерного матеріалу, який, як очікується, поліпшить чутливість і робочу смугу пропускання

Effect of Phenobarbitone Treatment Against Signal Grass (Brachiaria decumbens) Toxicity in Sheep

The effect of phenobarbitone against signal grass (Brachiaria decumbens) toxicity was studied in 26 male crossbred sheep. Grazing on signal grass significantly decreased the concentration of cytochrome P-450 and the activity of drug metabolizing enzymes, viz. aminopyrine-N-demethylase, aniline-4-hydroxylase, UDP- glucuronyltransferase and glutathione-S-transferase in liver and kidneys of affected sheep. Oral administration of phenobarbitone (30 mg/kg body weight) for five consecutive days before grazing on B. decumbens pasture, and thereafter, for three consecutive days every two weeks, resulted in significant increases in hepatic and renal activities of drug-metabolizing enzymes. The induction of drug metabolizing activity in sheep grazing on signal grass group was found to be lower than in animals given phenobarbitone alone. Induction by phenobarbitone provided a degree of protection against the toxic effects of B. decumbens as indicated by the delay in the appearance of signs of toxicity. Furthermore, these were much milder compared to those in the sheep not treated with phenobarbitone. The present study suggests that phenobarbitone-type cytochrome P-450 isoenzyme-induction may increase resistance against signal grass (B. decumbens) toxicity in sheep

Patients Undergoing Dental Surgery who are Taking Antiplatelet Medications

For the undergoing dental surgery patients taking antiplatelet medications, physicians and dentists must weigh the bleeding risks in continuing antiplatelet medications versus the thrombotic risks in interrupting antiplatelet medications. Bleeding complications requiring more than local measures for hemostasis are rare after dental surgery in patients taking antiplatelet medications. Conversely, the risk for thrombotic complications after interruption of antiplatelet therapy for dental procedures apparently is significant, although small. When a clinician is faced with a decision to continue or interrupt antiplatelet therapy for a dental surgical patient, the decision comes down to “bleed or die.” That is, there is a remote chance that continuing antiplatelet therapy will result in a (nonfatal) bleeding problem requiring more than local measures for hemostasis versus a small but significant chance that interrupting antiplatelet therapy will result in a (possibly fatal) thromboembolic complication. The decision is simple: It is time to stop interrupting antiplatelet therapy for dental surgery

Management of Major Trauma and the Role of Interventional Radiology

This study aimed at exploring the management of major trauma and analyzing the role of interventional radiology for major trauma patients. As there are no prospective randomized controlled trials of interventional radiology in major trauma. Therefore, this review aims to summarize the evidence supporting the use of interventional radiological techniques in the management of major trauma. The study concluded that interventional radiology has become an essential part of the modern trauma unit. Roles in pelvic haemorrhage and aortic injury are now well established and have contributed to improving patient survival and reducing long-term morbidity

(E)-1-(2,5-Dimethyl-3-thien­yl)-3-(2,4,5-trimeth­oxy­phen­yl)prop-2-en-1-one

In the title compound, C18H20O4S, the thio­phene and benzene rings are oriented at a dihedral angle of 10.83 (11)°. The central chain makes dihedral angles of 1.86 (13) and 9.25 (12)° with the benzene and thio­phene rings, respectively. In the crystal, mol­ecules are linked through weak inter­molecular C—H⋯O inter­actions. π–π inter­actions are also observed between the benzene rings with a centroid–centroid distance of 3.6832 (12) Å. The slippage between the benzene rings is 0.956 Å

2,4,5-Trimeth­oxy­benzaldehyde monohydrate

In the title compound, C10H12O4·H2O, the 2,4,5-trimeth­oxy­benzaldehyde mol­ecule is almost planar (rms deviation = 0.0183 Å). There is an R 1 2(5) ring motif due to O—H⋯O hydrogen bonding. In the crystal, the mol­ecules are stabilized in the form of one-dimensional polymeric chains extending along [010] due to O—H⋯O hydrogen bonding with adjacent water mol­ecules. The H atoms involved in inter­molecular hydrogen bonding are disordered over two sets of sites of equal occupancy