Significant Effect Of Pressure Research Articles

Biomechanical properties of veins cultured in vitro under elevated internal pressure.

The venous response to elevated blood pressure (BP) is of major importance because it is closely related to the etiology of venous diseases and the competency of vein grafts. In vitro culture experiments may provide useful information on the function of vein grafts because it is easier to separate mechanical and hemodynamic effects from other systemic influences compared to in vivo experiments. To study the effects of BP elevation on wall dimensions and mechanical properties of in vitro cultured veins. Rabbit femoral veins were cultured in vitro under internal pressures of 1 to 50 mmHg for 1 week, and their wall dimensions, biomechanical properties, and histology were determined. No significant differences were observed in internal vein diameter and wall thickness among vessels cultured at 10-50 mmHg compared to non-cultured control vessels. For an internal pressure of 10 mmHg applied to vessels during culture (equivalent to in vivo working BP), wall circumferential stress was maintained within control levels. There were no significant effects of pressure on basal tone and contractility of vascular smooth muscle and vascular compliance. The in vitro results were essentially similar to those obtained from previous in vivo animal experiments, indicating that in vitro tissue culture techniques are applicable to studies of venous remodeling.

Modification of the Ferromagnetic Properties of Si1 –xMnx Thin Films Synthesized by Pulsed Laser Deposition with a Variation in the Buffer-Gas Pressure

A series of thin films of Si1 –xMnx alloys with a thickness from 50 to 100 nm grown by pulsed laser deposition on an Al2O3 substrate in vacuum and in an argon atmosphere is investigated. The significant effect of the buffer-gas pressure in the sputtering chamber on the structural and magnetic homogeneity of the obtained films is shown. The conditions for the formation of a ferromagnetic phase with a high Curie temperature (>300 K) in the samples are studied. With the use of the Langmuir probe method, the threshold of ablation of a MnSi target by second harmonic radiation (λ = 532 nm) of a Nd:YAG Q-switch laser is determined. The time-of-flight curves for the plume ions are obtained with a change in the energy density at the target and argon pressure in the sputtering chamber. A nonmonotonic dependence of the probe time-of-flight signal amplitude on the argon pressure is established for high-energy particles of the plume.

Effect of time pressure on the burnout of home-visiting nurses: The moderating role of relational coordination with nursing managers.

To examine the main effects of time pressure and relational coordination with nursing managers on burnout and to further analyze the moderating role of relational coordination with nursing managers on the association between time pressure and burnout among home-visiting nurses in Japan. This was a cross-sectional, quantitative study comprising 93 home-visiting nurses in Japan. A hierarchical moderated regression analysis with mean-centered predictor variables was used to explore the main effects of time pressure and relational coordination with nursing managers on burnout and the moderating effect of relational coordination with nursing managers on the time pressure and burnout relationship. Time pressure was a significant positive predictor for emotional exhaustion and depersonalization, respectively. Relational coordination with the nursing managers was significantly and negatively related to depersonalization; however, its main effect on exhaustion was non-significant. Significant interaction effects of time pressure and relational coordination with the nursing managers on exhaustion and depersonalization also were identified. Time pressure was a significant positive contributor to exhaustion and depersonalization when the home-visiting nurses reported low relational coordination with the nursing managers. Relational coordination with nursing managers is a critical resource for dealing with high time pressure. Strategies, such as establishing a skill-mix program to alleviate nurses' time pressure and creating a supportive work environment to facilitate relational coordination with nursing managers, might be effective ways to prevent burnout, as well as management interventions among home-visiting nurses.

Women on Boards – The Influence of Corporate Elite

Although we can observe noticeable progress in gender diversity on corporate boards, they are still far from gender balanced. Our paper builds on social identity theory to discuss the impact of corporate elite – multi-board men, who are sitting in multiple corporate boards – on board diversity. The empirical analysis, based on DAX 30 firms in the period of 2010-2015, shows that multi-board men resist women’s participation while the presence of multi-board and C-level women positively influences gender diversity on boards. We extend the main argument of social identity theory about homophily favorism by suggesting that multi-board men repel women on boards in order to protect their monopoly value generated from their majority status. Additionally, we find a significant effect of time pressure from the introduction of gender quota in Germany binding in 2016, which indicates that gender quota is an effective policy for board gender diversity.

Optimization of feeding rate and pressure of Orthodox Roller in Black Tea production

The objective of this study was to optimize the performance of orthodox roller (225 kg) in black tea manufacturing by varying the pressure and feeding rate at Wewassa Tea Factory, Passara. Three levels of pressure (P1 - 10 min-no pressure, 10 min-touch bar, P2 - 10 min-no pressure, 5 min-1/4 pressure,5min-no pressure and P3 - 10 min - no pressure, 3 min-1/4 pressure, 2 min - 1/2 pressure) and three levels of feeding rate to the roller (200, 205 and 210 kg) were used as treatment combinations. Currently, the factory using P1 pressure and 200 kg feeding rate for tea manufacturing. Particle size analysis, brightness, TF/TR and organoleptic properties were measured for the triplicate samples and compared with the sample prepared with the factory standard. The results revealed, there is a significant effect of pressure and feeding rate on particle size analysis, but there is no significant effect on color, ratio between theaflavins (TF), thearubigins (TR) and sensory analysis (p<0.05) The treatment combination of feeding rate 210 kg and Pressure P2 has given high amount of particle size belongs to No 3 mesh size while conserving other chemical and organoleptic parameters, thus it can be concluded that this treatment combination is the best.

Lattice thermal transport in superhard hexagonal diamond and wurtzite boron nitride: A comparative study with cubic diamond and cubic boron nitride

Hexagonal diamond (h-C) and wurtzite boron nitride (w-BN) are two superhard materials recently identified to be comparable to or even harder than their cubic counterparts, cubic diamond (c-C) and cubic boron nitride (c-BN). To understand the effect of lattice structure on thermal transport in these materials, we conduct first-principles calculations to investigate their harmonic and anharmonic lattice properties. Owing to the strong C-C or B-N bonds, h-C and w-BN are found to have a high lattice thermal conductivity (κL) exceeding the overall thermal conductivity of metals, albeit lower than that of their cubic counterparts. By analyzing the phonon band structure and volume of the 3-phonon scattering phase space, we attribute the lower κL of the hexagonal phases to their larger volume of 3-phonon scattering phase space than the cubic ones. Moreover, we reveal that a high pressure of 125 GPa leads to a two-to three-fold increase in the κL of these materials, because the pressure enlarges the optical-acoustic phonon bandgap and thus reduces the volume of the 3-phonon scattering phase space. This work uncovers the significant effect of lattice structure and pressure on phonon scattering and transport, which is crucial for the application of superhard materials.

Response Surfaces of Linoleic Acid of Swietenia Mahagoni in Supercritical Carbon Dioxide

The process variables pressure, temperature and particle size were studied for optimization of linoleic acid by response surface methodology following a Box-Behnken design of experiments. The results indicated the effect of extraction condition on linoleic acid of the extracts produced SC-CO2 gave the different effect. But, Analysis of the variance of the data indicated that there was no statistically significant difference between the other sample. Although there was greater variation within the sample, there was still no statistically significant effect of temperature and pressure on the extraction. The optimum conditions for linoleic acid yield from Swieteniamahagoni seed within the experimental range were found to be pressure of 29.02 MPa, a temperature of 67.88ºC and particle size 0.75 mm, and the predicted linoleic acid was found to be 34.91%.

Evolution of the Mass Loss Rate During Atmospheric and Pressurized Slow Pyrolysis of Wheat Straw in a Bench-Scale Reactor

A deep study focused on the significant effect of the absolute pressure on the yield of produced gas during the slow pyrolysis of biomass was carried out. In addition, the evolution of the mass loss rate linked to the pyrolysis process was also analyzed.

One-year effects of a group-based lifestyle intervention in adults with type 2 diabetes: A randomized encouragement trial

AimsTo estimate the real-world effects of offering a group-based lifestyle intervention (GLI) to adults with diabetes. MethodsThis randomized encouragement trial included adult primary care patients in metropolitan Chicago with type 2 diabetes and body mass index ≥24 kg/m2. Participants were randomized to standard care (brief dietary and lifestyle counseling) or standard care plus being encouraged, but not required, to participate in a free-of-charge GLI offered by the YMCA. The GLI was a group-based adaptation of the Look AHEAD lifestyle intervention. ResultsOf 331 participants, 167 were randomized to standard care and 164 to the GLI encouragement arm. About one third of participants were non-Hispanic White (34.4%). In the GLI arm, 75 (45.7%) attended ≥1 GLI visits. In the primary intention-to-treat analysis, the effect of GLI encouragement was 0.95% weight loss at six months (95% confidence interval [CI], 0.13–1.77%; P = 0.02), and 1.20% weight loss at 12 months (95% CI, 0.05–2.36%; P = 0.04). At 12 months, there was a 0.30% (3.3 mmol/mol) reduction in hemoglobin A1c, but this result did not achieve statistical significance (P = 0.054). In instrumental variable analysis estimating effects among the subgroup of participants who attended any GLI visits, the effect of GLI attendance was 2.30% weight loss at six months (95% CI, 0.30–4.30%; P = 0.02), and 2.07% weight loss at 12 months (95% CI, 0.25–3.88%; P = 0.02). We detected no significant blood pressure or cholesterol effects. ConclusionsAmong adults with type 2 diabetes, a group-based lifestyle intervention in a community-based setting achieved modest weight loss at 6 and 12 months.Clinical trial registration: ClinicalTrials.gov Identifier NCT01435603.

Characterization of Neem (Azadirachta indica A. Juss) seed volatile compounds obtained by supercritical carbon dioxide process.

Extraction process employing Supercritical fluid carbon dioxide (SCF) yields bioactive compounds near natural forms without any artifact formation. Neem seed was subjected to SCF at different temperatures and pressure conditions. These extracts were partitioned to separate volatile fraction and were analyzed by Gas Chromatography-Mass spectroscopy along with the volatiles extracted by the hydro-distillation method. Experimental results show that there is a significant effect of pressure and temperature on isolation of a number of volatile compounds as well as retention of biologically active compounds. Twenty-five volatile compounds were isolated in the Hydro-distillate compare to the SCF extract of 100bar, 40°C which showed forty volatile compounds corresponds to 76.38 and 92.39% of total volatiles respectively. The majority of bioactive compounds such as Terpinen-4-ol, 1,2,4-Trithiolane, 3,5-diethyl, allyl isopropyl sulphide, Cycloisolongifolene, á-Bisabolene, (-)-α-Panasinsen, Isocaryophyllene, trans-Sesquisabinene hydrate, 1-Naphthalenol, were identified in the extract when isolated at 100bar and 40°C.

Changes of energy potential on clay particle surfaces at high pressures

Abstract Bentonite and kaolin were treated by high pressure (to 2200 MPa). Using the XRD parameters (full width at half maximum, integrated intensity, interplanar distance, diffraction angle 2θ of reflection maximum), a significant pressure effect on the crystallite size of main clay minerals (montmorillonite and kaolinite) was established. The crystallite size is closely related to the energy activity of the clay particles. The boundaries with a pressure of 125 and 750 MPa were identified, which divide the measurements into three classes. Each class has its own regularities for changing parameters. Mathematical models for predicting changes in energy activity of clay particles have been developed.

The Effect of Fuel Electrode Roughness on the Properties of Plasma Sprayed Solid Oxide Cells

Solid oxide cell electrolytes fabricated by atmospheric plasma spraying are frequently found to have considerable gas leak rates. Electrode surface roughness is known to have an influence on electrolyte leak rates. A jet of high velocity air, produced with an air knife, was aimed at the plasma plume during fuel electrode deposition to reduce the surface roughness prior to electrolyte deposition. The resulting fuel electrode masses, electrode compositions, and electrode surface roughnesses were measured for varying air knife inlet pressures. Surface asperity populations and maximum heights were significantly reduced using air knife pressures of >6 bar at the expense of deposition efficiency. The nickel volume fraction in the fuel electrode increased slightly with increasing air knife pressure. Open circuit voltages were larger on the smoother fuel electrodes that were produced at higher air knife pressures, but no significant effect of air knife pressure on cell power density could be discerned.

Модификация ферромагнитных свойств тонких пленок Si-=SUB=-1-x-=/SUB=-Mn-=SUB=-x-=/SUB=-, синтезируемых методом импульсного лазерного осаждения при изменении давления буферного газа

AbstractA series of thin films of Si_1 –_ x Mn_ x alloys with a thickness from 50 to 100 nm grown by pulsed laser deposition on an Al_2O_3 substrate in vacuum and in an argon atmosphere is investigated. The significant effect of the buffer-gas pressure in the sputtering chamber on the structural and magnetic homogeneity of the obtained films is shown. The conditions for the formation of a ferromagnetic phase with a high Curie temperature (&gt;300 K) in the samples are studied. With the use of the Langmuir probe method, the threshold of ablation of a MnSi target by second harmonic radiation (λ = 532 nm) of a Nd:YAG Q -switch laser is determined. The time-of-flight curves for the plume ions are obtained with a change in the energy density at the target and argon pressure in the sputtering chamber. A nonmonotonic dependence of the probe time-of-flight signal amplitude on the argon pressure is established for high-energy particles of the plume.

A matter of time? Challenging and hindering effects of time pressure on work engagement

ABSTRACTThe aim of our research was to test time-exposure effects of time pressure as a stressor typically considered to be a challenge, rather than a hindrance stressor. We examined the within- and between-person effects of time pressure on work engagement in two diary/panel studies with employees using intervals of five days and three weeks, respectively (Study 1, n = 350, and n = 357, respectively) and six to eight weeks (Study 2, n = 238). We assumed that it is a matter of time whether time pressure acts as a challenge (under short-term exposure) or as a hindrance stressor (under long-term exposure). We found significant positive within-person effects of time pressure on work engagement when controlling for strain in the daily and weekly diary assessment (Study 1), but a significant negative within-person effect in the six to eight weeks’ assessment (Study 2). The between-person effects were significant and negative in all studies. Although a short-term increase can be beneficial for a certain time, stable and long-time exposure of time pressure does rather reduce work engagement. Thus, employers should not keep time pressure permanently high to motivate their employees. However, short-term increases of time pressure (e.g. before a deadline) may serve as a motivating factor.

Development of a dilatometer for shrinkage analysis of thermosetting resin systems at accurate processing conditions of liquid composite moulding processes and exemplary results of the effects of varying processing conditions on chemical shrinkage of an epoxy resin

The processing of thermosetting resin systems in liquid composite moulding is accompanied by a change in density through chemical and thermal shrinkage during the curing reaction of the resin and cooling of a part from processing to operating temperature. These effects cause residual stresses and an undesired characteristic surface pattern in endless fibre reinforced plastics. However, the accurate measurement of the chemical and thermal shrinkage is challenging with state-of-the-art measurement devices, especially for highly reactive thermosetting resin systems. The main disadvantage is that it is not possible to recreate the processing conditions of modern liquid composite moulding processes during the measurement of the thermosetting resin systems and has therefore limited use for process optimisations. In this paper the development of a dilatometer, which is capable of measuring the shrinkage in highly reactive thermosetting resins providing the processing conditions of liquid composite moulding is presented. The effects of processing pressure and internal mould release agents on chemical shrinkage are analysed with the developed dilatometer for different epoxy resins. The trials demonstrate a significant effect of processing pressure on chemical shrinkage.

Inactivation kinetics, structural, and morphological modification of mango soluble acid invertase by high pressure processing combined with mild temperatures

The activity, structure and morphology of mango soluble acid invertase (SAI) were investigated after high pressure processing (HPP) combined with mild temperature at 50–600MPa and 40–50°C. The activity of mango SAI was efficiently reduced by HPP at 50MPa/45 and 50°C, or 600MPa/40, 45 and 50°C, while it was increased by 10–30% after HPP at 50–200MPa/40°C. Significant antagonistic effect of pressure and temperature on the activity of SAI was observed at 50–400MPa/50°C. The secondary structure of SAI was not influenced by HPP. However, its tertiary structure was modified by HPP, and severer modification occurred with higher pressure, higher temperature, and longer treatment time. Results of atomic force microscope suggested that HPP at 400MPa/50°C for 2.5min induced dissociation of SAI, and HPP at 600MPa/50°C for 30min resulted aggregation of SAI.

Intensive Blood Pressure Lowering in Patients With and Patients Without Type 2 Diabetes: A Pooled Analysis From Two Randomized Trials.

The Action to Control Cardiovascular Risk in Diabetes Blood Pressure (ACCORD-BP) study did not find a significant beneficial effect of intensive systolic blood pressure (SBP) lowering on cardiovascular events in hypertensive patients with type 2 diabetes mellitus (T2DM), while the Systolic Blood Pressure Intervention Trial (SPRINT) did find a significant beneficial effect in patients without T2DM. The objective of this analysis was to assess the effect of both T2DM and baseline cardiovascular disease risk on the treatment effect of intensive blood pressure lowering. The individual patient data from the ACCORD-BP and SPRINT studies were pooled and follow-up durations harmonized. Both studies randomized hypertensive patients to an SBP target of <120 mmHg or a target of <140 mmHg. The composite primary end point consisted of unstable angina, myocardial infarction, acute heart failure, stroke, and cardiovascular death. The interaction between intensive blood pressure lowering and both T2DM and 10-year cardiovascular risk was assessed using Cox proportional hazards models. The cohort consisted of 14,094 patients with mean age 66 ± 8.9 years and mean baseline SBP 139.5 ± 15.6 mmHg; 33.6% had T2DM. The hazard ratio for the primary composite end point was 0.82 (95% CI 0.73-0.93), P = 0.0017. The interaction between intensive blood pressure lowering and T2DM was nonsignificant (P = 0.13). The 10-year cardiovascular risk was higher in primary prevention patients with T2DM, but risk did not interact with the treatment effect (P = 0.84). Intensive blood pressure lowering may have a similar favorable effect and appears to decrease cardiovascular events in both patients with and patients without T2DM.

High Pressure Experiments on Metal‐Silicate Partitioning of Chlorine in a Magma Ocean: Implications for Terrestrial Chlorine Depletion

AbstractIn the bulk silicate Earth, chlorine is more depleted than other elements with similar volatilities; however, the cause of terrestrial chlorine depletion is not well understood. Two major hypotheses have been proposed to explain this depletion: Incorporation into the Earth's metallic core and escape to space. The former hypothesis can be tested by investigating the partitioning of chlorine between iron‐rich metallic liquids and silicate melts. In this study, we investigated the experimental partitioning of chlorine between iron‐rich metallic liquids and silicate melts at pressures from 4 to 23 GPa and temperatures from 1,650 to 2,400°C using multi‐anvil presses. The results demonstrate that chlorine is moderately to highly lithophile under the experimental conditions. In sulfur‐free experiments, chlorine becomes slightly more siderophile as temperature increases and less siderophile as pressure increases. For sulfur‐bearing experiments, no significant effects of pressure or temperature were observed. Based on these data and thermodynamic considerations, we obtained empirical laws to estimate chlorine partition coefficients between iron‐rich metallic liquids and silicate melts. Under the P‐T conditions that would have controlled metal‐silicate equilibration during core segregation in the Earth, the calculated metal‐silicate partition coefficients for chlorine are much lower than unity. This result suggests that terrestrial chlorine that may have been present in the accreting Earth was not partitioned into its core, supporting that escape to space is the more likely hypothesis. If terrestrial chlorine was lost to space, chlorine depletion may have resulted from the loss of the primordial hydrosphere during the formation of the Earth.

Evaluating the effect of ammonia-water dilution pressure and its density on thermodynamic performance of combined cycles by the energy-exergy analysis approach

The purpose of this study is to investigate the significant effect of ammonia-water dilution pressure and density on the thermodynamic performance of ammonia-water combined cycle through energy and exergy destruction, enthalpy temperature, yields, and flow velocity. The energy-exergy analysis is conducted on the ammonia water combined cycle and the Rankine cycle, respectively. Engineering Equation Solver (EES) software is utilized for performing such detailed analyses. Values and ratios regarding heat drop and exergy loss is presented in separate tables for different equipment. The results obtained by the energy-exergy analysis indicate that net power increases with the increasing ammonia-water dilution pressure in the boiler. This trend continues until pressure range reach in [169.3 – 180] bar and after that, it starts to decrease. In addition, the increasing of ammonia-water dilution pressure leads to reduction of boiler both exergy and total exergy destructions, it also results in an increment in the exergy performance coefficient (EPC). Moreover, it is also noticed that the combined cycle system improves its efficiency by about 5.81% compared with gas turbines.DOI: http://dx.doi.org/10.5755/j01.mech.23.2.18110

Study on the applicability of dynamic light scattering (DLS) to microemulsions including supercritical carbon dioxide-swollen micelles

The applicability of dynamic light scattering (DLS) for the characterization of the size of supercritical carbon dioxide (sc-CO2)-swollen micelles in a polyester polyol-based multicomponent microemulsion with nonionic surfactant has been thoroughly proved for the first time in this work. Systematic experiments confirming that a hydrodynamic mode is observable in either a homodyne or a heterodyne detection scheme as well as the evaluation of the influence of the laser power applied to the slightly colored microemulsion have ensured an accurate implementation of this technique for a technically relevant system. The correlation times associated with the translational diffusion coefficient of the swollen micelles in a continuous liquid phase were measured for temperatures from (298.15 to 338.15)K at pressures of (90 and 100)bar. While there was no significant effect of pressure, it was found that the translational diffusion coefficient increases with increasing temperature as expected. We postulate this is primarily related to the effect of decreasing viscosity of the continuous phase. An estimation of the hydrodynamic diameter of the sc-CO2-swollen micelles is in good agreement with values for similar systems reported in the literature. For the derivation of absolute sizes for corresponding systems, also dynamic viscosity and refractive index data will be determined simultaneously in a currently developed closed experimental loop.