scholarly journals Analysis of the mechanical resistance of cement with aggregates of petrous endocarp from macadamia nut

2022 ◽  
Vol 2159 (1) ◽  
pp. 012008
Author(s):  
A S Pérez-Valdovinos ◽  
S Arceo-Díaz ◽  
E E Bricio-Barrios ◽  
J A Ojeda-Sánchez ◽  
J R Moreno-Peña ◽  
...  
Keyword(s):  
Factorial Design ◽  
Physical Dependence ◽  
Mechanical Resistance ◽  
Control Groups ◽  
Average Resistance ◽  
Macadamia Nut ◽  
Contour Plots

Abstract This research evaluates if adding crushed macadamia nutshell to a mixture of cement and sand could result in lighter and more resistant constructive materials. The mechanical resistance under compression of cement blocks made from two different experimental mixtures, in which a certain amount of sand is replaced with crushed nutshell, is compared against two control groups. Results show that blocks made from one of the proposed mixtures got an average resistance around 50% above the controls group while being 3% lighter. Additionally, the physical dependence of the strength of the blocks on the granulometry of the aggregated endocarp fragments, and their percentage to the volume of cement, was studied thanks to contour plots developed from a factorial design of the data.

scholarly journals Implementation of experimental design methodology in preparation and characterization of zolmitriptan loaded chitosan nanoparticles

2017 ◽  
Vol 6 (3) ◽  
pp. 16-22 ◽  
Author(s):  
Satish K. Mandlik ◽  
Nisharani S. Ranpise
Keyword(s):  
Statistical Analysis ◽  
Factorial Design ◽  
High Speed ◽  
Chitosan Nanoparticles ◽  
Spherical Shape ◽  
Entrapment Efficiency ◽  
Pharmaceutical Journal ◽  
Optimization Method ◽  
Fickian Diffusion ◽  
Contour Plots

The present study investigated the implementation of 32 factorial design of experiment and statistical analysis for the optimization of chitosan nanoparticles containing zolmitriptan an antimigraine drug. The influence of chitosan concentration (X1) and sodium tripoly phosphate (X2) on responses namely nanoparticle size (Y1), and entrapment efficiency (Y2), was studied. As per design, nine runs of nanoparticles were prepared by modified ionic gelation method using high speed vortex mixing. The particle size was found in the range of 151-880 nm and entrapment efficiency was 72.3-81.2%. A statistical analysis was performed using licensed design expert software V.8.0 with respect to ANOVA, regression analysis. The contour plots and response surface plots showed visual representation of relationship between the experimental responses and the set of independent variables. Regression model equations were validated by a numerical and graphical optimization method. Further, optimized drug loaded nanoparticles showed +23.7mV zeta potential indicating storage stability, electron micrograph reflects spherical shape and mixed type of drug release followed by Fickian diffusion (n=0.266) was observed. Thus, using systematic factorial design approach, desirable goals can be achieved in shortest possible time with lesser number of experiments which was proven to be an effective tool in quality by design.Mandlik and Ranpise, International Current Pharmaceutical Journal, February 2017, 6(3): 16-22http://www.icpjonline.com/documents/Vol6Issue3/01.pdf

Effect of Postoperative Peroxide Bleaching on the Marginal Seal of Composite Restorations Bonded With Self-etch Adhesives

2013 ◽  
Vol 38 (6) ◽  
pp. 644-654 ◽  
Author(s):  
A Roubickova ◽  
M Dudek ◽  
L Comba ◽  
D Housova ◽  
P Bradna
Keyword(s):  
Electron Microscopy ◽  
Chemical Degradation ◽  
Mechanical Resistance ◽  
Control Groups ◽  
Peroxide Bleaching ◽  
Composite Restorations ◽  
Etch And Rinse ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Self Etch

SUMMARY The aim of this study was to determine the effect of peroxide bleaching on the marginal seal of composite restorations bonded with several adhesive systems. Combined cylindrical Class V cavities located half in enamel and half in dentin were prepared on the buccal and lingual surfaces of human molars. The cavities were bonded with the self-etch adhesives Clearfil SE-Bond (CLF), Adper Prompt (ADP), and iBond (IBO) and an etch-and-rinse adhesive Gluma Comfort Bond (GLU) and restored with a microhybrid composite Charisma. Experimental groups were treated 25 times for eight hours per day with a peroxide bleaching gel Opalescence PF 20, while the control groups were stored in distilled water for two months and then subjected to a microleakage test using a dye penetration method. Scanning electron microscopy was used to investigate the etching and penetration abilities of the adhesives and morphology of debonded restoration-enamel interfaces after the microleakage tests. Statistical analyses were performed using nonparametric Kruskal-Wallis, Mann-Whitney, and Wilcoxon tests at p=0.05. The microleakage of all GLU groups was low and not significantly affected by peroxide bleaching. Low microleakage was recorded for CLF control groups, but after bleaching, a small but significant increase in microleakage at the enamel margin indicated its sensitivity to peroxide bleaching. For ADP and IBO control groups, the microleakage at the enamel margins was significantly higher than for GLU and CLF and exceeded that at the dentin margins. Bleaching did not induce any significant changes in the microleakage. Electron microscopy analysis indicated that in our experimental setup, decreased adhesion and mechanical resistance of the ADP- and IBO-enamel interfaces could be more important than the chemical degradation effects induced by the peroxide bleaching gel.

scholarly journals Influence of dependent variables on granule formulation using factorial design: microwave irradiation as one of the factor

2013 ◽  
Vol 2 (7) ◽  
pp. 115-118 ◽  
Author(s):  
Prameela Rani Avula ◽  
Hema Veesam
Keyword(s):  
Factorial Design ◽  
Pharmaceutical Journal ◽  
Flow Property ◽  
Dosage Forms ◽  
Regression Equations ◽  
Dependent Variables ◽  
Granule Formulation ◽  
Traditional Drug ◽  
Contour Plots ◽  
The Impact

As traditional drug delivery poses many disadvantages such as difficulty in consumption, the granules were opted to replace tablet dosage forms available in the market. A 23 full factorial design was employed for the formulation and characterization of the granule dosage form of oxcarbazepine. From regression equations we can assess the impact of each factor on the response further contour plots helped to pre-analyze the desired target factor values, in addition optimization process helped to analyze the values of dependent variables. Thus as of the results achieved a preferred response of flow property and drug release was obtained. In the current study, an attempt has been made to minimize possible number of experiments in the formulation of granule dosage forms. Polyvidone is a hydrophilic binder and primellose is a good disintegrate to obtain higher dissolution rate. A part, microwave assisted drying process plays a major role in achieving desired flow properties of granules.DOI: http://dx.doi.org/10.3329/icpj.v2i7.15153 International Current Pharmaceutical Journal, June 2013, 2(7): 115-118

Countercontrol in Hypnotic Control Groups

1976 ◽  
Vol 39 (3_suppl) ◽  
pp. 1083-1089
Author(s):  
William W. Moyer
Keyword(s):  
College Students ◽  
Factorial Design ◽  
Control Groups ◽  
Hypnotic Suggestions

The tendency of unhypnotized subjects to countercontrol or adjust their performance in opposition to the perceived hypothesis of the experimenter was studied in a 2 × 3 factorial design, with susceptibility as the first factor and amnesia, hypermnesia or control suggestions as the second factor. Relearning rates were measured for the 42 unhypnotized college students who served as subjects. Results showed that hypermnesic subjects adjusted their relearning rates in opposition to the suggestion given to them. Implications for the use of hypnotic suggestions with unhypnotized control groups were discussed.

scholarly journals Ex vivo biomechanical testing of Funkquist B dorsal laminectomy between the sixth and seventh cervical vertebrae in dogs

2022 ◽  
Vol 52 (3) ◽  
Author(s):  
Julián Andres Sanjuan Galíndez ◽  
Bruno Watanabe Minto ◽  
Paulo Vinicius Tertuliano Marinho ◽  
Adrielly Dissenha ◽  
Dayvid Vianeis Farias de Lucena ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Mechanical Test ◽  
Cervical Vertebrae ◽  
Maximum Load ◽  
Cervical Region ◽  
Average Weight ◽  
Mechanical Resistance ◽  
Control Groups ◽  
Dorsal Laminectomy ◽  
Flexion And Extension

ABSTRACT: Dorsal laminectomy is routinely performed for spinal cord compressions or stenosis of the cervical vertebral canal. However, despite good results, relevant complications have been described in dogs. Considering the incomplete understanding of the necessity for complementary surgical stabilization after performing laminectomies in the cervical region, this study compared the resistance and range of motion (ROM) of the cervical spinal column subjected to Funkquist B laminectomy between the sixth and seventh vertebrae in dogs. Forty-four cervical vertebral columns (C2-T1) of dogs, with an average weight of 26.2±3.8 kg, were selected using radiography and computed tomography. Four experimental groups (n=11) were established according to the mechanical test: two control groups (flexion and extension control) and two laminectomy groups (flexion and extension laminectomies). Numerical results of the maximum load for measuring the resistance and ROM of the columns of the two control groups and the two laminectomy groups were compared. The laminectomy groups showed a lower maximum load, regardless of the mechanical test performed (P<0.001). The ROM was not influenced by laminectomy, the type of mechanical test (ventral flexion or extension), or its interaction (P<0.05). There was no interaction between the effect of the laminectomy factors (yes or no) and the effect of the mechanical tests for ventral flexion or extension (P<0.05). In conclusion, Funkquist B dorsal cervical laminectomy between C6 and C7 decreases mechanical resistance with a supraphysiological loading force but does not alter the ROM, suggesting that it can be used without additional mechanical stabilization in dogs.

Optimization of Composition and Process for Preparing Metaxalone Nanosuspension using Factorial Design

2016 ◽  
Vol 6 (3) ◽  
Author(s):  
Lakshmi Gubbala ◽  
Srinivas Arutla ◽  
Vobalaboina Venkateshwarlu
Keyword(s):  
Zeta Potential ◽  
Factorial Design ◽  
Methyl Cellulose ◽  
Drug Dissolution ◽  
Optimum Process ◽  
Process Conditions ◽  
Lauryl Sulfate ◽  
Independent Variables ◽  
Drug Nanoparticles ◽  
Contour Plots

In the current study, the composition and process for preparing the nanosuspension of metaxalone (MX) has been optimized by using design of experiments (DOE). MX is skeletal muscle relaxant and belongs to BCS class II1 , the class wherein invivo drug dissolution is a rate-limiting step for drug absorption2 . High pressure homogenization (HPH) method was used to prepare the nanosuspension and Hydroxy propyl methyl cellulose (HPMC) and sodium lauryl sulfate (SLS) as surface stabilizers. For optimization studies three square (32 ) factorial design was used. For the composition optimization, concentration of the stabilizers and for process optimization homogenization time and pressure are used as independent variables. The dependent variables were particle size (PS), polydispersity index (PDI), zeta potential (ZP). The relationship between the dependent and independent variables was studied by response surface plots and contour plots. From the data it has been observed that 2.5 % HPMC, 0.5 % SLS were optimum concentrations and 1000 bar pressure, 120 minutes of homogenization were optimum process conditions producing least PS, PDI and high zeta potential. The optimized nano composition prepared by using optimum process conditions was observed to release more than 80 % within 30 minutes and found to be stable after 3 months of storage at room temperature. The solid state characterization (XRD, DSC) data of spray dried nanoparticles of the optimized composition has shown retention of drug crystallinity. IR has shown drug is compatible with the excipients used. SEM photograph has shown spherical drug nanoparticles. The optimization studies by applying the DOE resulted in considerable decrease in the experimentation work to achieve the stable nanosuspension with desired parameters such as PS, PDI and ZP.

scholarly journals Assessment of the Influence of Graphene Nanoparticles on Thermal Conductivity of Graphene/Water Nanofluids Using Factorial Design of Experiments

2018 ◽  
Vol 62 (3) ◽  
pp. 317-322 ◽  
Author(s):  
Srinivasan Manikandan Periasamy ◽  
Rajoo Baskar
Keyword(s):  
Thermal Conductivity ◽  
Fluid Flow ◽  
Factorial Design ◽  
Flow Rate ◽  
Inlet Temperature ◽  
Fluid Temperature ◽  
Fluid Flow Rate ◽  
23 Factorial Design ◽  
Contour Plots ◽  
Factorial Design Of Experiments

In this study, 23 factorial design of experiment was employed to evaluate the effect of parameters of hot fluid inlet temperature, graphene nanofluid concentration and hot fluid flow rate on thermal conductivity of graphene/water nanofluid. The levels of  hot fluid inlet temperature are kept at 35°C and 85°C, nanofluid concentration is kept at 0.1 and 1.0 volume% (vol.%) and the hot fluid flow rate are kept at 2 lpm and 10 lpm. Experiments were conducted with 16 runs as per MINITAB design software using graphene/water nanofluids in the corrugated plate type heat exchanger.  The nanofluid thermal conductivity was determined using the mixing rule for different nanofluid concentrations ranging from 0.1 to 1.0%. Normal, Pareto, Residual, Main and Interaction effects, Contour Plots were drawn. The Analysis of Variance (ANOVA) of test results depict that the hot fluid temperature and nanofluid concentration have significant effect on the thermal conductivity of graphene/water nanofluid (response variable).

Hepatocyte Alterations in Guinea Pigs FED Polychlorinated Biphenyls (PCBs), Dibenzodioxins (PCDD), AND DIBENZOFURANS (PCDF)

1982 ◽  
Vol 40 ◽  
pp. 56-57
Author(s):  
J. N. Turner ◽  
D. N. Collins
Keyword(s):  
Guinea Pigs ◽  
Room Temperature ◽  
Dose Group ◽  
Methyl Cellulose ◽  
Uranyl Acetate ◽  
Target Organ ◽  
Office Building ◽  
Lead Citrate ◽  
Control Groups ◽  
Cooling Fluid

A fire involving an electric service transformer and its cooling fluid, a mixture of PCBs and chlorinated benzenes, contaminated an office building with a fine soot. Chemical analysis showed PCDDs and PCDFs including the highly toxic tetra isomers. Guinea pigs were chosen as an experimental animal to test the soot's toxicity because of their sensitivity to these compounds, and the liver was examined because it is a target organ. The soot was suspended in 0.75% methyl cellulose and administered in a single dose by gavage at levels of 1,10,100, and 500mgm soot/kgm body weight. Each dose group was composed of 6 males and 6 females. Control groups included 12 (6 male, 6 female) animals fed activated carbon in methyl cellulose, 6 males fed methyl cellulose, and 16 males and 10 females untreated. The guinea pigs were sacrificed at 42 days by suffocation in CO2. Liver samples were immediately immersed and minced in 2% gluteraldehyde in cacadylate buffer at pH 7.4 and 4°C. After overnight fixation, samples were postfixed in 1% OsO4 in cacodylate for 1 hr at room temperature, embedded in epon, sectioned and stained with uranyl acetate and lead citrate.

The limits of human performance

2008 ◽  
Vol 44 ◽  
pp. 11-26 ◽  
Author(s):  
Ralph Beneke ◽  
Dieter Böning
Keyword(s):  
Human Performance ◽  
Safety Margin ◽  
Afferent Input ◽  
Metabolic Energy ◽  
Human Organism ◽  
Mechanical Resistance ◽  
As Doping ◽  
Gene And Protein Expression ◽  
Underlying Mechanisms ◽  
Biochemical Research

Human performance, defined by mechanical resistance and distance per time, includes human, task and environmental factors, all interrelated. It requires metabolic energy provided by anaerobic and aerobic metabolic energy sources. These sources have specific limitations in the capacity and rate to provide re-phosphorylation energy, which determines individual ratios of aerobic and anaerobic metabolic power and their sustainability. In healthy athletes, limits to provide and utilize metabolic energy are multifactorial, carefully matched and include a safety margin imposed in order to protect the integrity of the human organism under maximal effort. Perception of afferent input associated with effort leads to conscious or unconscious decisions to modulate or terminate performance; however, the underlying mechanisms of cerebral control are not fully understood. The idea to move borders of performance with the help of biochemicals is two millennia old. Biochemical findings resulted in highly effective substances widely used to increase performance in daily life, during preparation for sport events and during competition, but many of them must be considered as doping and therefore illegal. Supplements and food have ergogenic potential; however, numerous concepts are controversially discussed with respect to legality and particularly evidence in terms of usefulness and risks. The effect of evidence-based nutritional strategies on adaptations in terms of gene and protein expression that occur in skeletal muscle during and after exercise training sessions is widely unknown. Biochemical research is essential for better understanding of the basic mechanisms causing fatigue and the regulation of the dynamic adaptation to physical and mental training.

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