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Fulltext Lowering cholesterol, blood pressure, or both to prevent cardiovascular events: results of 8.7 years of follow-up of Heart Outcomes Evaluation Prevention (HOPE)-3 study participants

Bosch J, Lonn EM, Jung H, Zhu J, Liu L, Lopez-Jaramillo P, et al.

Eur Heart J, 2021 08 17;42(31):2995-3007.
PMID: 33963372 DOI: 10.1093/eurheartj/ehab225

AIMS: Rosuvastatin (10 mg per day) compared with placebo reduced major adverse cardiovascular (CV) events by 24% in 12 705 participants at intermediate CV risk after 5.6 years. There was no benefit of blood pressure (BP) lowering treatment in the overall group, but a reduction in events in the third of participants with elevated systolic BP. After cessation of all the trial medications, we examined whether the benefits observed during the active treatment phase were sustained, enhanced, or attenuated.
METHODS AND RESULTS: After the randomized treatment period (5.6 years), participants were invited to participate in 3.1 further years of observation (total 8.7 years). The first co-primary outcome for the entire length of follow-up was the composite of myocardial infarction, stroke, or CV death [major adverse cardiovascular event (MACE)-1], and the second was MACE-1 plus resuscitated cardiac arrest, heart failure, or coronary revascularization (MACE-2). In total, 9326 (78%) of 11 994 surviving Heart Outcomes Prevention Evaluation (HOPE)-3 subjects consented to participate in extended follow-up. During 3.1 years of post-trial observation (total follow-up of 8.7 years), participants originally randomized to rosuvastatin compared with placebo had a 20% additional reduction in MACE-1 [95% confidence interval (CI), 0.64-0.99] and a 17% additional reduction in MACE-2 (95% CI 0.68-1.01). Therefore, over the 8.7 years of follow-up, there was a 21% reduction in MACE-1 (95% CI 0.69-0.90, P = 0.005) and 21% reduction in MACE-2 (95% CI 0.69-0.89, P = 0.002). There was no benefit of BP lowering in the overall study either during the active or post-trial observation period, however, a 24% reduction in MACE-1 was observed over 8.7 years.
CONCLUSION: The CV benefits of rosuvastatin, and BP lowering in those with elevated systolic BP, compared with placebo continue to accrue for at least 3 years after cessation of randomized treatment in individuals without cardiovascular disease indicating a legacy effect.
TRIAL REGISTRATION NUMBER: NCT00468923.

Matched MeSH terms: Blood Pressure
Fulltext Theoretical modeling of pseudo hydrostatic force in solid-liquid pipe flow with two layer

Hussain H. Al-Kayiem, Iylia Elena Abdul Jamil

Pertanika Journal of Science & Technology, 2013;21(2):521-532.
MyJurnal

In the moving layer of particles with variable concentration, the shear estimation is not directly predictable and there is no existing clear mathematical or empirical formula to achieve this objective. This paper presents a developed approach to estimate the shear forces in a flow having suspended and moving layers of solid particles in liquid flow. The two-layer approach was taken whereby the flow consisting of one upper suspended layer of particles in the liquid, and the bottom layer was the moving bed of particles. In the present work, the method of finding the force acting on the pipe wall by the particles in the layer, termed as the ‘dry force’, was presented using a “pseudo hydrostatic pressure” method. To attain the equation for the dry force, a mathematical approach is taken with the assumptions that the flow is horizontal, two-phase pipe flow (solid in Newtonian liquid), incompressible and it is at steady-state. The analysis was conducted considering various particles densities, various concentrations in the suspended layer and different thicknesses of the moving bed. Changing the concentration in the suspended layer from 0.00001 up to 0.001 didn’t showed significant changes in the dry force evaluation. The dry friction force is increasing with increasing moving bed thickness. The developed mathematical model can be
applicable in solving for the shear force in horizontal solid liquid two-phase flows.

Matched MeSH terms: Hydrostatic Pressure
Fulltext Correlation between the bending strength and the thickness interlayer of alumina-mild steel friction welded at lower rotational speed

Mohamad Zaky Noh, Luay Bakir Hussain, Zainal Arifin Ahmad

Journal of Nuclear and Related Technologies, 2007;2007(1):75-82.
MyJurnal

The joining of ceramic-metal could be done through a few techniques: brazing, diffusion bonding, friction welding etc. However, the mechanism of ceramic-metal joining was still not properly understood. In this study, alumina rod was bonded to mild steel rod via friction welding technique by using Al 1100 sheet as interlayer. The diameter of the rods was 10 mm. Friction pressure of 20 MPa and forging pressure of 40 MPa were used. Rotational speeds were maintained at 900 rpm and friction times of 2 to 20 seconds were applied. The joining strength was determined through four point bending test. The maximum bending strength, 240 MPa was obtained at the friction times of 20 seconds. Under optical microscope and SEM observation, the deformation of the aluminum interface was clearly obtained. Mechanical interlocking and close contact between the aluminaaluminum and aluminum-mild steel were observed at magnifications of 3000X. The strength of alumina-steel bonding is much dependent on the wettability of the alumina surface by the molten aluminum and the existing of mechanical interlocking between interlayer and sample materials.

Matched MeSH terms: Pressure
Fulltext Gamma scan technique for detecting coupon inside the mother pipeline

Rasif Mohd Zain, Roslan Yahya, Mohamad Rabaie Shari, Airwan Affandi Mahmood, Mior Ahmad Khusaini Adnan

Jurnal Sains Nuklear Malaysia, 2012;24(2):28-34.
MyJurnal

Many times a year natural gas transmission and distribution companies need to make new connections to pipelines to expand or modify their existing system through hot tapping procedure. This procedure involves the installation of a new pipeline connection while the pipeline remains in service, flowing natural gas under pressure. The hot tap procedure includes attaching a branch connection and valve on the outside of an operating pipeline, and then cutting out the pipe-line wall within the branch and removing the wall section, which is called object of coupon through the valve. During the hot tapping process a critical problems occurred when a coupon fell into the mother pipeline. To overcome this problem, a gamma-ray absorption technique was chosen whereby a mapping technique will be done to detect the coupon position. The technique is non-destructive as it applies Co-60 (5mCi) as a radioisotope sealed source to emit gamma radiation and a NaI(Tl) scintillation as detector. The result provided a visible representation of density profile inside pipeline where the coupon location can be located. This paper provides the detail of the technique used and presents the result obtained.

Matched MeSH terms: Pressure
Trends of reactive hyperaemia responses to repetitive loading on skin tissue of rats - Implications for pressure ulcer prevention

Yapp JH, Kamil R, Rozi M, Mohtarrudin N, Loqman MY, Ezamin AR, et al.

J Tissue Viability, 2017 Aug;26(3):196-201.
PMID: 28438463 DOI: 10.1016/j.jtv.2017.03.002

Tissue recovery is important in preventing tissue deterioration, which is induced by pressure and may lead to pressure ulcers (PU). Reactive hyperaemia (RH) is an indicator used to identify people at risk of PU. In this study, the effect of different recovery times on RH trend is investigated during repetitive loading. Twenty-one male Sprague-Dawley rats (seven per group), with body weight of 385-485 g, were categorised into three groups and subjected to different recovery times with three repetitive loading cycles. The first, second, and third groups were subjected to short (3 min), moderate (10 min), and prolonged (40 min) recovery, respectively, while fixed loading time and pressure (10 min and 50 mmHg, respectively). Peak hyperaemia was measured in the three cycles to determine trends associated with different recovery times. Three RH trends (increasing, decreasing, and inconsistent) were observed. As the recovery time is increased (3 min vs. 10 min vs. 40 min), the number of samples with increasing RH trend decreases (57% vs. 29% vs. 14%) and the number of samples with inconsistent RH trend increases (29% vs. 57% vs. 72%). All groups consists of one sample with decreasing RH trend (14%). Results confirm that different recovery times affect the RH trend during repetitive loading. The RH trend may be used to determine the sufficient recovery time of an individual to avoid PU development.

Matched MeSH terms: Pressure Ulcer/prevention & control; Pressure/adverse effects
Assessment of sitting pressure on Malaysian bus drivers

Ahmad Rasdan Ismail, Mohd Afiq Zainal Rosli, Isa Halim, Baba Md. Deros, Mohd Nizam Ab Rahman, Md. Mustafizur Rahman

Journal of Occupational Safety and Health, 2012;9(3):1-9.
MyJurnal

The main purpose of this study was to establish the comfort zone for bus drivers in a seated position. In addition, this study is to investigate the seated pressure distribution among Malaysian bus drivers. The study consists of 10 bus drivers randomly selected to be a part of this study. The FSA pressure mat was utilized in order to investigate the force distribution of buttock to the seat pan of the drivers’ seat. This device is placed on the driver seat and backrest. Later, the subject would sit on for several minute. The finding reveals that most of the bus drivers feel discomfort by having low back pain and musculoskeletal disorder. The seat pressure distribution of Malaysian busses indicated that the seat not able to absorb high pressure generated from buttock that later may cause the discomfort and restricted the performance of drivers.

Matched MeSH terms: Pressure
Fulltext The effect of effective diameter on fluidization quality in compartmented fluidized bed gasifier

Wee, Siaw Khur, Chok, Vui Soon, Gorin, Alexander, Chua, Han Bing, Yan, Hong Ming

Pertanika Journal of Science & Technology, 2009;17(2):-.
MyJurnal

Compartmented Fluidized Bed Gasifier (CFBG), consisting of two compartments - the combustorand gasifier, uses air blown instead of pure oxygen for syngas production in bubbling fluidization mode, eliminating the need of air separation unit, and reducing the capital cost, thus distinguishes it from other traditional ones. Fluidization quality is a determining factor in the CFBG to guarantee its well-lifted behaviour. Previous study, without solid circulation at ambient conditions, brought to the fore the necessity of considering the effect of the minimum allowable effective diameter. The study was then performed in the CFBG cold physical model of 0.66m overall diameter (effective diameter for combustor and gasifier is 0.413m and 0.257m) to investigate the fluidization quality and compare it with the results obtained from the previous cold model of about 1.36 times smaller, but with the same compartmented ratio of 65:35. Different inert particles (river sand, quartz sand and alumina) were used, over a range of aspect ratios, for the aforementioned objective. The results showed that the fluidization quality in the gasifier has not been achieved and the degradation of fluidization quality in the combustor is still observed, notwithstanding the fact that the condition of the minimum allowable effective diameter has been met. The reduction of distributor free area, to increase the distributor pressure drop, showed a marginal effect on the quality. The effect of the minimum allowable effective diameter on fluidization quality in CFBG as well as the interplay of geometric and operational parameters require further studies be carried out. The fluidization quality of the binary mixture is also currently under investigation.

Matched MeSH terms: Pressure
Fulltext Modelling of motion resistance ratios of pneumatic and rigid bicycle wheels

Ahmad, D., Jamarei, O., Sulaiman, S., Fashina, A.B., Akande, F.B.

Pertanika Journal of Science & Technology, 2013;21(1):59-74.
MyJurnal

The motion resistances of 660 mm pneumatic and rigid bicycle wheels of the same rim diameter were measured experimentally using the developed tractor-towed single non-lug narrow wheel motion resistance test rig for traction studies. The motion resistances measured were taken to be the towing forces determined in real time using Mecmesin Basic Force Gauge (BFG 2500). The test variables included two test surfaces [tilled and wet (mud) surfaces], the dynamic load and the towing velocity. The tyre inflation pressure of 414 kPa was chosen to make the surface synonymous with that of the rigid wheel. Motion resistance ratios of the two wheels were determined empirically and through semi-empirical approach. The motion resistances of the rigid wheel were found to be greater than those of the pneumatic wheel for both surfaces. Consequently, the motion resistance ratios of the rigid wheel were greater than those obtained
from the pneumatic wheel. Analysis of variance showed that there were significant differences between the means of the motion resistance measured on the test surfaces, as well as between the two wheels and their interactions with the test surfaces. The motion resistance ratio exhibited a linear relationship with the towing velocity, while the relationship with the dynamic load was quadratic. However, such a relationship is either direct or inverse with the respective variables. The motion resistance ratio models for the pneumatic and rigid wheels showed that on different test conditions of the dynamic loads and the towing velocities, the relationships between the motion resistance ratio and the dynamic load, and motion resistance with dynamic load were also different.

Matched MeSH terms: Pressure
Fulltext Total phenolic content and antioxidant activity of quercus infectoria galls using supercritical co extraction technique and its comparison with soxhlet extraction

Hasmida, M.N., Liza, M. S., Nur Syukriah, A.R., Harisun, Y., Mohd Azizi, C. Y., Fadzilah Adibah, A. M.

Pertanika Journal of Science & Technology, 2015;23(2):287-295.
MyJurnal

Quercus infectoria gall, which is known as manjakani in Malaysia, was traditionally used in treating diseases. The bioactive compounds from the galls can be extracted using various extraction methods. In this study, supercritical carbon dioxide (SC-CO2) extraction was used to study the effects of CO2 flow rate on the yield, total phenolic content and antioxidant activity of Q. infectoria extract by fixing the pressure and temperature at the highest density (P: 30 MPa, T: 40°C). The results were compared with those acquired from the Soxhlet extraction method. The results showed that the Soxhlet extraction had a higher percentage of extraction yield than SC-CO2 extraction. The selectivity of Q. infectoria extracts using SC-CO2 extraction was better than the Soxhlet extraction method. Meanwhile, the extraction efficiency using the SC-CO2 extraction ranged from 46% to 53%. The SC-CO2 extraction also yielded higher total phenolic content than using the Soxhlet extraction method when 2 mL/min of CO2 flow rate was applied (203.53 mg GA/g sample). This study also revealed that the extracts from the SC-CO2 extraction showed a better radical scavenging activity compared to the Soxhlet extraction when analysed using DPPH (2,2-diphenyl-1-picryl hydrazyl) radical scavenging activity assays.radical scavenging activity compared to the Soxhlet extraction when analysed using DPPH (2,2-diphenyl-1-picryl hydrazyl) radical scavenging activity assays.

Matched MeSH terms: Pressure
Fulltext Effect of sintering properties on the formation of yttrium iron garnet by powder preparation method for microwave ferrite resonator antenna

Wan Fahmin Faiz Wan Ali, Mohd Fadhil Ain, Zainal Arifin Ahmad

Journal of Nuclear and Related Technologies, 2012;2012(2):47-55.
MyJurnal

Triyttrium Pentairon (iii) Oxide (Y3Fe501,2) or familiar called as Yttrium Iron Garnet (YIG) is successfully prepared using a conventional mixed-oxide method of 5:3 Fe to Y ratios. YIG prepared from conventional mixed-oxide usually produced some associated phase which surely will affect electrical properties. In this study, various temperature used in the sintering process to induce associated phases (YIP) to be fully reacting to form single phase of YIG and the effect on resonance frequency is studied for resonator applications. The mixtures of oxide powders are calcined at 1100 "C and sintered at various temperatures of (1350, 1380, 1400, 1420 1450 QC, respectively). Cubic phase is detected from the formation of YIG. Some other phases such as YIP and hematite also present as secondary phase. However, it is seen that, based on the Rietvield refinement method, the total amount of secondary phase simulated are inversely proportional with sintering temperature. The powder was pressed into cylindrical pellet and tested as a microwave resonator in antenna application. It was found that, on the actual antenna circuit the operating frequencies measured are in the range of 10-12 GHz for all samples which suitable for X-band. At the end, overall radiation pattern for all samples exhibit an omnidirectional behavior.

Matched MeSH terms: Pressure
Fulltext Analysis of shotcrete lining of underground tunnels

Ghiasi, Vahed, Husaini Omar

Pertanika Journal of Science & Technology, 2011;19(2):249-257.
MyJurnal

Shotcrete is a process where concrete is projected or “shot” under pressure, using a feeder or a
“gun” onto a surface to form structural shapes including walls, floors, and roofs. The surface can
be wood, steel, polystyrene, or any other surfaces that concrete can be projected onto. The surface
can be trowel led smooth while the concrete is still wet. Shotcrete has high strength, durability, low
permeability, excellent bond, and limitless shape possibilities. These properties allow shotcrete
to be used as a structural material in most cases. Although the hardened properties of shotcrete
are similar to conventional cast-in-place concrete, the nature of the placement process provides
additional benefits, such as excellent bond with most substrates and instant or rapid capabilities,
particularly on complex forms or shapes. In addition to building homes, shotcrete can also be used
to build pools. The practice of underground tunneling shows that the degree of stability of tunnels
is dependent on the state of the soil, rock mass, and shotcrete around the tunnel contour. The
development in the urban or suburban areas leads to the construction of tunnels in all kinds of soil
and rock. Meanwhile, the construction of tunnels in shallow depth or soft soils causes the ground
to displace. The determination of soil and rock mechanical properties to assess the stability of New
Austrian Tunnelling Method (NATM) tunnels and design the support system is one of the most
important steps in tunnelling. This paper provides information pertaining to the safety and increase
the stability of NATM tunnel before, during and after the operation of the tunnel. Therefore, the
shotcrete process is a recognized method for cemented sandy silt stabilization, with the aid of high
pressure shot concrete to increase the stability of tunnels.

Matched MeSH terms: Pressure
Fulltext Non-intrusive capacitance tomography for on-line visualization gas-liquid flow in horizontal pipe

Mustapha, I., Takriff, M.S., Kamaruddin, S.K., Hassan, N.M., Zain, R.M.

Journal of Nuclear and Related Technologies, 2009;2009(2):41-48.
MyJurnal

Electrical capacitance tomography (ECT) velocimetry technique was utilized in this study to quantify the flow structure of gas-liquid based on the ECT images. A new 8 electrodes sensor ECT has been successfully developed to provide 2D images in a cross section of pipeline. The ECT has been attentively applied in the test section of the flow rig for imaging the gas-liquid distribution. The inside diameter of ECT pipeline sensor is 100mm. Meanwhile, the flow rig consists of close loop of “CPVC” pipes that includes a pipe test section, two tanks of oil and water respectively and allows the working pressure up to 5 bars. Transparent pipe is used for visual monitoring. A portable Doppler flow meter that utilizes the ultrasonic signal has also been placed at the test section to measure the velocity. The images obtained by ECT show that the different flow patterns have been observed in the horizontal pipe during the experiment. The technique enables realization of the time and position at which particle density fluctuations with respect to dominant time-space levels pass through the pipeline.

Matched MeSH terms: Pressure
Fulltext The effect of fibre alignment, fibre treatment and pre-irradiation on the mechanical and environmental properties of kenaf-reinforced polypropylene composites

Sharifah Hanisah S.A. Aziz, Khairul Zaman Mohd Dahlan, Jalaluddin Harun

Journal of Nuclear and Related Technologies, 2008;2008(1):33-44.
MyJurnal

At present, research in composite materials is being directed at using natural fibres instead of synthetic fibres. Kenaf which is extensively grown in the Far East including Malaysia, has been identified as a bast (stem) fibre with significant market potential. In this work, long and random kenaf fibres (non-woven mat form) were used in the as-received condition and alkalized with a 0.06M NaOH solution. They were combined with polypropylene thin sheets, sandwiched between layers of kenaf fibres and hot-pressed to form natural fibre composites. The mechanical properties of the composites were investigated to observe the effect of fibre alignment, fibre treatment and pre-irradiation method used. A general trend was observed whereby alkalized and long fibre composites gave higher flexural modulus and flexural strength compared with random mat and untreated fibres. The long fibre composites also gave a higher work of fracture. However, the correlation between fibre surface treatment and the work of fracture was less clear. Pre-irradiation on the polypropylene pellets and fibres before the composite is manufactured showed significant improvement on the flexural modulus and flexural strength. The bond performance test performed on the treated composites demonstrated good bonding and interfacial adhesion between the fibre and matrix. However, the method of moulding used need to be improved to optimize the performance of the composites.

Matched MeSH terms: Pressure
Fulltext Effects of process parameters on selected properties of liquid compression-molded vinyl ester sheets

Mohd. Sapuan Salit, Mohamed Abd. Rahman, Khalina Abdan

Pertanika Journal of Science & Technology, 2011;19(1):147-152.
MyJurnal

Vinyl esters combine the best of polyesters and epoxies in terms of properties and processing. Without
complicating presence of reinforcing fibres, this study investigated the effects of catalyst amount, preheating time, molding temperature, and pressure on flexural and water absorption properties of cast vinyl ester (VE) using a factorial experiment. Longer preheating time enhanced the stiffness of VE, while higher molding pressure reduced the flexural modulus. All the four factors did not affect the flexural strength and elongation at the break of molded VE significantly. Using a high molding pressure also caused molded VE to have higher water absorption for a long water exposure period. Meanwhile, greater water absorption at bigger amount of catalyst and higher preheating temperature indicate possible interactions between these factors. The results suggest possible negative effects of high molding pressure through the increase in the network of micro-cracks, and thus lowering the integrity of cast VE sheets. Judicious selection of the process parameters was required in order to obtain good quality molded VE sheets and by extension fibre-reinforced VE composites. Molded VE-unsaturated polyester (UP) blend is a significantly different material which is 1.49 times stronger, 2.38 times more flexible, but it is 0.69 less stiff than neat VE and with significantly higher water absorption. The results obtained warrant for a further investigation in process optimization of VE molding and the use of VE-UP blend as a matrix for natural fibre-reinforced composites.

Matched MeSH terms: Pressure
Fulltext Optimization of process condition for extraction of gelatin from red tilapia skin (Oreochromis niloticus) by High Pressure Processing (HPP)

Yusof, N., Jaswir, I., Jamal, P., Jami, M.S., Octavianti, F.

International Food Research Journal, 2017;24(101):0-0.
MyJurnal

Extraction of gelatin using traditional acid-base pretreatment method has several limitations
such as time consuming and causes serious water pollution. Chemical treatment often being used
as an alternative process to overcome the weaknesses of the conventional method. However,
excessive chemical elements would damage the structure of the gelatin due to its high sensitivity
to the acid content. High Pressure Processing (HPP) is a novel and environmental friendly
method that has been suggested to assist gelatin extraction. Pressurization during pretreatment
could reduce the extraction time and amount of acid used. It also has a potential in enhancing the
properties of the gelatin extract and increasing the gelatin yield. In this research, One-Factor-
at-Time (OFAT) and optimization study were done to determine the optimum parameters for
extraction of gelatin assisted by HPP from red tilapia skin. Four parameters; applied pressure,
pressure holding time, ratio of acid to skin and extraction time have been selected for the OFAT
design and concentration of the gelatin extract and percentage of yield gelatin were evaluated.
From OFAT, optimum technical parameters for response surface optimization design were 250
MPa pressure, 7.5 ml of acid to 1 g of skin and 12 hours extraction time. Pressure holding
time was fixed for 10 min. FCCCD has been used for optimization study. Results from the
data shows that the optimum conditions for gelatin extraction from red tilapia skin were 250
MPa for pressure, 10 min of pressure holding time, 7.5 ml of acid for 1 g of skin and 12 hours
of extraction time while the maximum concentration and yield were 19.51 mg/ml and 32.04%
(320.4 mg/g), respectively. These findings proved that HPP could increase the concentration
and the yield of the gelatin while reducing the chemical waste and shortening the extraction
process.

Matched MeSH terms: Pressure
Fulltext Analysis of fill time and injection pressure of multiple 20 gram Parisons during injection moulding process

Najiy Rizal Suriani Rizal, Azuddin Mamat, Aidah Jumahat

Pertanika Journal of Science & Technology, 2017;25(103):233-240.
MyJurnal

In recent years, injection moulding process is one of the most advanced and efficient manufacturing processes for mass production of plastic bottles. However, a good quality of parison is difficult to achieve due to uncontrollable humidity, pressure inlet and water inlet velocity. This paper investigates the effect of using multiple mould cavities to improve the process fill time and injection pressure in the production of PET plastic bottles using MoldFlow software. The modelling of parison was developed using CATIA with the consideration of every part of the parison. MoldFlow software was used to analyse the flow of 20 g parison with different cavity numbers (1, 8, 16, 24 cavity), as well as its corresponding runner size towards its fill time and injection pressure. Other important parameters that affect the production of parison, such as melting temperature, mould temperature, atmospheric temperature and cooling time, were remained constant. The fill time required to produce 24 moulds was improved by 60% compared to using 8 mould cavity only, and this enable the production of more plastic bottles in a day. Therefore, fill time and injection pressure are two important parameters to be considered in the injection moulding process, especially to reduce parison defect and increase its production rate.

Matched MeSH terms: Pressure
Fulltext Tensile and compressive properties of unidirectional Arenga Pinnata fibre reinforced epoxy composite

Aidah Jumahat, Muhamad Faris Syafiq Khalid, Zuraidah Salleh, Mohammad Jawaid

Pertanika Journal of Science & Technology, 2017;25(107):299-308.
MyJurnal

This paper presents a study on the effect of Arenga Pinnata fibre volume fraction on the tensile and compressive properties of Arenga Pinnata fibre reinforced epoxy composite (APREC). The composites were produced using four different Arenga Pinnata fibre volume contents, which were 10vol%, 15vol%, 20vol%, and 25vol%, in unidirectional (UD) fibre alignment. Tensile and compression tests were performed on all APREC specimens in order to investigate the effect of fibre volume fraction on modulus of elasticity, strength and strain to failure. The morphological structure of fractured specimens was observed using scanning electron microscopy (SEM) in order to evaluate the fracture mechanisms involved when the specimens were subjected to tensile or compressive loading. The results indicated that the higher the amount of Arenga Pinnata fibres, the higher the stiffness of the composites. This is shown by the increment of tensile and compressive modulus of the specimens when the fibre volume content was increased. Tensile modulus increased up to 180% when 25vol% Arenga Pinnata fibre was used in APREC compared to Pure Epoxy specimen. It can also be observed that the tensile strength of the specimens increased 28% from 53.820 MPa (for Pure Epoxy) to 68.692 MPa (for Epoxy with 25vol% APREC addition). Meanwhile, compressive modulus and strength increased up to 3.24% and 9.17%, respectively. These results suggest that the addition of Arenga Pinnata fibres significantly improved the tensile and compressive properties of APREC.

Matched MeSH terms: Pressure
Fulltext Relationship between intraocular pressure lowering effect and chemical structure of imidazo[1,2-a]benzimidazole and pyrimido[1,2-a]benzimidazole derivatives

Vassiliev P, Iezhitsa I, Agarwal R, Marcus AJ, Spasov A, Zhukovskaya O, et al.

Data Brief, 2018 Jun;18:340-347.
PMID: 29896521 DOI: 10.1016/j.dib.2018.02.067

This article contains data that relate to the study carried out in the work of Marcus et al. (2018) [1]. Data represent an information about pharmacophore analysis of imidazo[1,2-a]benzimidazole and pyrimido[1,2-a]benzimidazole derivatives and results of construction of the relationship between intraocular pressure (IOP) lowering activity and hypotensive activity of imidazo[1,2-a]benzimidazole and pyrimido[1,2-a]benzimidazole derivatives using a multilayer perceptron artificial neural network. In particular, they include the ones listed in this article: 1) table of all pharmacophores of imidazo[1,2-a]benzimidazole and pyrimido[1,2-a]benzimidazole derivatives that showed IOP lowering activity; 2) table of all pharmacophores of the compounds that showed absence of IOP lowering activity; 3) table of initial data for artificial neural network analysis of relationship between IOP activity and hypotensive activity of this chemical series; 4) graphical representation of the best neural network model of this dependence; 5) original txt-file of results of pharmacophore analysis; 6) xls-file of initial data for neural network modeling; 7) original stw-file of results of neural network modeling; 8) original xml-file of the best neural network model of dependence between IOP lowering activity and hypotensive activity of these azole derivatives. The data may be useful for researchers interested in designing new drug substances and will contribute to understanding of the mechanisms of IOP lowering activity.

Matched MeSH terms: Intraocular Pressure
Fulltext Data on the effects of imidazo[1,2-a]benzimidazole and pyrimido[1,2-a]benzimidazole compounds on intraocular pressure of ocular normotensive rats

Marcus AJ, Iezhitsa I, Agarwal R, Vassiliev P, Spasov A, Zhukovskaya O, et al.

Data Brief, 2018 Jun;18:523-554.
PMID: 29896529 DOI: 10.1016/j.dib.2018.03.019

This data is to document the intraocular pressure (IOP) lowering activity of imidazo[1,2-a]benzimidazole and pyrimido[1,2-a]benzimidazole compounds in ocular normotensive rats. Effects of single drop application of imidazo[1,2-a]benzimidazole and pyrimido[1,2-a]benzimidazole compounds on IOP in ocular normotensive rats are presented at 3 different concentrations (0.1%, 0.2% and 0.4%). Time course of changes in IOP is presented over 6 h period post-instillation. The IOP lowering activities of test compounds were determined by assessing maximum decrease in IOP from baseline and corresponding control, duration of IOP lowering and area under curve (AUC) of time versus response curve. Data shown here may serve as benchmarks for other researchers studying IOP-lowering effect of imidazo[1,2-a]benzimidazole and pyrimido[1,2-a]benzimidazole compounds and would be useful in determining therapeutic potential of these test compounds as IOP lowering agents.

Matched MeSH terms: Intraocular Pressure
A theoretical study of substitutional boron-nitrogen clusters in diamond

Croot A, Othman MZ, Conejeros S, Fox N, Allan N

J Phys Condens Matter, 2018 Aug 31.
PMID: 30168449 DOI: 10.1088/1361-648X/aade16

Substitutional clusters of multiple light element dopants are a promising route to the elusive shallow donor in diamond. To understand the behaviour of co-dopants, this report presents an extensive first principles study of possible clusters of boron and nitrogen. We use periodic hybrid density functional calculations to predict the geometry, stability and electronic excitation energies of a range of clusters containing up to five N and/or B atoms. Excitation energies from hybrid calculations are compared to those from the empirical marker method, and are in good agreement. When a boron-rich or nitrogen-rich cluster consists of 3 - 5 atoms, the minority dopant element - a nitrogen or boron atom respectively - can be in either a central or peripheral position. We find B-rich clusters are most stable when N sits centrally, whereas N-rich clusters are most stable with B in a peripheral position. In the former case, excitation energies mimic those of the single boron acceptor, while the latter produce deep levels in the band-gap. Implications for probable clusters that would arise in high-pressure high-temperature (HPHT) co-doped diamond and their properties are discussed.

Matched MeSH terms: Pressure

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