scholarly journals Physical and Mechanical Properties of Three Varieties of Mango

2019 ◽  
pp. 1-8
Author(s):  
T. Osadare ◽  
O. O. Koyenikan ◽  
F. F. Akinola
Keyword(s):  
Geometric Mean ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Arithmetic Mean ◽  
Angle Of Repose ◽  
Average Value ◽  
Universal Testing ◽  
Crushing Force ◽  
Significant Difference ◽  
Mango Seed

Physical properties of three varieties of mango were studied at 13.75% and 8.74% moisture content levels. Some selected properties such as geometric mean, arithmetic mean, angle of repose, sphericity and crushing force were determined. The average tri-axial dimensions of the seeds gave 38.00 ± 6.8, 42.23 ± 4.12, 33.95 ± 6.91 as average major diameter; 35.60 ± 5.68, 39.18 ± 3.95, 31.44 ± 7.56 as average intermediate diameter and 24.76 ± 5.2, 28.42 ± 5.59, 23.08 ± 3.67 as average minor diameter for Kerosene, Sheri and Sugar mango respectively. The average sphericity of the three varieties of mango seed was 0.74, 0.77 and 0.67 while that of the angle of repose was 40.430, 08.030 and 09.760 for Kerosene, Sheri and Sugar mango respectively. The average crushing force determined using the universal testing machine gave 21.00 N, 10.58 N and 9.46 N for Kerosene, Sheri and Sugar mango respectively. Statistical analysis shows that there is a significant difference in the geometric mean between Kerosene mango and Sheri mango and no significant difference between Sheri mango and Sugar mango, while the average value of the calculated arithmetic mean was found to be statistically different within the three varieties but no significant difference in sphericity. Kerosene mango has the highest value for the angle of repose and crushing force.

Measurement of Physical and Mechanical Properties of Russian Olive (Elaeagnus Angustifolia L.) Fruit

2016 ◽  
Vol 12 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Mohammad Hossein Nadian ◽  
Mohammad Hossein Abbaspour-fard
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Loading Rate ◽  
Geometric Mean ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Angle Of Repose ◽  
Shear Mode ◽  
Russian Olive ◽  
Double Shear

Abstract The effect of moisture content on some properties of two varieties (Meymeh and Maragheh) of Russian olives was studied. The physical and mechanical properties including: dimensions, geometric mean diameter, thousand mass, volume, sphericity, surface area, true and bulk densities, porosity, angle of repose, coefficient of friction, rupture force, and rupture energy. The changes of moisture content levels from 17% to 25% (w.b.) indicated a statistically significant effect on all studied physical properties, except bulk density for Russian olive fruits. Shearing force was applied to the fruit using a testing machine in double shear mode. Shear strength and shearing energy increased with increase of loading rate; however, they were higher in Meymeh variety than Maragheh variety. Therefore, the lowest loading rate, with up to about 10 mm/min is desirable to design a suitable pulverizing mill in the herbal medicine industries.

scholarly journals Effects of Fluorosis and Self Etching Primers on Shear Bond Strengths of Orthodontic Brackets

2009 ◽  
Vol 03 (03) ◽  
pp. 173-177 ◽  
Author(s):  
Ahmet Yalcin Gungor ◽  
Hakan Turkkahraman ◽  
Necdet Adanir ◽  
Huseyin Alkis
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Orthodontic Brackets ◽  
Universal Testing ◽  
Adhesive Remnant Index ◽  
Halogen Light ◽  
Significant Difference ◽  
Bond Strengths ◽  
Group Ii ◽  
Clinical Changes

ABSTRACTObjectives: To evaluate the effects fluorosis and self etching primers (SEP) on shear bond strengths (SBS) of orthodontic brackets.Methods: A total of 48 (24 fluorosed and 24 non-fluorosed) non-carious freshly extracted human permanent premolar teeth were used in this study. Fluorosed teeth were selected according to the modified Thylstrup and Fejerskov index (TFI), which is based on the clinical changes in fluorosed teeth. Fluorosed and non-fluorosed teeth were randomly assigned to 4 groups of 12 each. In groups I (non-fluorosed teeth) and II (fluorosed teeth), standard etching protocol was used and brackets were bonded with Light Bond. In groups III (non-fluorosed teeth) and IV (fluorosed teeth), Transbond Plus SEP was used and brackets were bonded with Transbond XT Light Cure Adhesive. All specimens were cured with a halogen light. After bonding, SBS of the brackets were tested with Universal testing machine. After debonding, all teeth and brackets in the test groups were examined under 10x magnifications. Any adhesive remained after debonding was assessed and scored according to the modified Adhesive Remnant Index (ARI).Results: ANOVA indicated a significant difference between groups (P<.001). SBS in group II (Light Bond+Fluorosis) were significantly lower than other groups. ARI scores of the groups were also significantly different (P<.001). There was a greater frequency of ARI scores of 1,2 and 3 in group II (Light Bond+Fluorosis).Conclusions: When standard etching protocol was used enamel fluorosis significantly decreased the bond strength of orthodontic brackets. Satisfactory bond strengths were obtained when SEP was used for bonding brackets to the fluorosed teeth. (Eur J Dent 2009;3:173-177)

scholarly journals Load-Application Devices: A Comparative Strain Gauge Analysis

2015 ◽  
Vol 26 (3) ◽  
pp. 258-262 ◽  
Author(s):  
Renato Sussumu Nishioka ◽  
Luis Gustavo Oliveira de Vasconcellos ◽  
Renata Pilli Jóias ◽  
Sigmar de Mello Rode
Keyword(s):  
Strain Gauge ◽  
Repeated Measures ◽  
Testing Machine ◽  
Acrylic Resin ◽  
Load Application ◽  
Chromium Alloy ◽  
Axial Loads ◽  
Nickel Chromium ◽  
Universal Testing ◽  
Significant Difference

In view of the low loading values commonly employed in dentistry, a load-application device (LAD) was developed as option to the universal testing machine (UTM), using strain gauge analysis. The aim of this study was to develop a load-application device (LAD) and compare the LAD with the UTM apparatus under axial and non-axial loads. An external hexagonal implant was inserted into a polyurethane block and one EsthetiCone abutment was connected to the implant. A plastic prosthetic cylinder was screwed onto the abutment and a conical pattern crown was fabricated using acrylic resin. An impression was made and ten identical standard acrylic resin patterns were obtained from the crown impression, which were cast in nickel-chromium alloy (n=10). Four strain gauges were bonded diametrically around the implant. The specimens were subjected to central (C) and lateral (L) axial loads of 30 kgf, on both devices: G1: LAD/C; G2: LAD/L; G3: UTM/C; G4: UTM/L. The data (με) were statistically analyzed by repeated measures ANOVA and Tukey's test (p<0.05). No statistically significant difference was found between the UTM and LAD devices, regardless of the type of load. It was concluded that the LAD is a reliable alternative, which induces microstrains to implants similar to those obtained with the UTM.

scholarly journals Effect Of Accelerating Aging On Retention And The Release Period Of Clips In A Bar Retained Maxillary Implant Overdenture

2021 ◽  
Vol 8 ◽  
Author(s):  
Dalia El naggar ◽  
Ahmed Mohamed Alam-Eldein ◽  
Maha Mostafa Halim ◽  
Hoda Mohammed Amin Rashad
Keyword(s):  
Testing Machine ◽  
Accelerated Aging ◽  
The Other ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
Retention Loss ◽  
Significant Difference ◽  
Implant Overdenture

Objectives: This study was made to detect the effect of accelerating aging on retention and measuring the release period of clips in a 2 and 3 bar retained maxillary implant overdenture. Materials and Methods: Four implants were placed in two maxillary edentulous epoxy models. One model had two bar attachments with two clips overdenture while the other model had three bar attachments with three clips in the overdenture. Retention and release period of the clips were checked before applying insertion removal cycles. Retention was measured using universal testing machine after 540 cycles (6 months) and 1080 cycles (1 year) of insertion removal on a chewing simulator.Results and Conclusions: There was a significant difference in retention and release period between two bars and three bars implant retained maxillary overdentures. A significant difference was also seen in each group after accelerated aging. Therefore, the three bar implant retained overdenture had higher retention values than two bar. Retention loss occurred in both groups after the insertion removal cycles. Release period value was lower in two bar overdenture than three bar overdenture.

Studies on engineering properties of multiplier onion

2021 ◽  
Vol 45 (01) ◽  
pp. 11-18
Author(s):  
B. B. Devojee ◽  
A. Carolin Rathinakumari ◽  
A. K. Dave ◽  
Senthil Kumaran
Keyword(s):  
Geometric Mean ◽  
Physical And Mechanical Properties ◽  
Shape Index ◽  
Angle Of Repose ◽  
Engineering Properties ◽  
Onion Bulb ◽  
Vegetable Crops ◽  
Onion Bulbs ◽  
Successful Design ◽  
Multiplier Onion

The knowledge of physical and mechanical properties of onion bulb is important for successful design of any planter. Multiplier onion is propagated through bulbs and bulbs are planted manually. Manual planting of onion bulb is highly labour intensive (80-100 man-days ha-1) due to the close plant geometry (plant to plant and row to row spacing is 10 × 15 cm) among the vegetable crops. Engineering properties of multiplier onion were determined in order to design and develop a tractor operated raised bed onion bulb planter. In multiplier onion each onion comprises of 4-5 bulbs. These bulbs were cleaned, separated into single bulbs and divided in to 9 categories manually based on their individual weight viz., <2g, 2-3 g, 3-4 g, 4-5 g, 5-6 g, 6-7 g, 7-8 g, 8-9 g, >9 g. The onion bulb had a moisture content of 80.62±0.87 %. It was observed that the properties varied for different sizes of onion grades and the grades had highly significant effect on most of the properties. The linear dimensions of onion bulbs viz., length, width, thickness for nine grades ranged from 21.21±2.60 to 32.31±3.30 mm, 13.54±1.77 to 30.95±2.91 mm and 10.91±1.40 to 22.63±2.15 mm. The geometric mean diameter, sphericity, shape index and projected area all ranged from 28.22±2.04 to 14.54±0.96 mm, 0.87±0.06 to 0.69±0.08, 1.78±0.32 to 1.22±0.14 and 5.50±0.51 to 1.55±0.30 cm2, respectively. The one hundred onion bulb weight, bulk density, true density were in the range of 1185±19.59 to 121.6±6.30 g, 793.20± 9.45 to 480.19±13.13 kg.m-3, 1086± 205.22 to 1013.6±348.85 kg.m-3, respectively. The angle of repose decreased with increase in size of onion bulbs. The interaction between sphericity, shape index and angle of repose indicated that as the size of the onion size increase angle of repose decreased.

The Effect of Thermoforming on Tear Strength of Ethylene Vinyl Acetate Mouthguard Material in Various Thicknesses

2017 ◽  
Vol 751 ◽  
pp. 657-662
Author(s):  
Phakphum Srinuan ◽  
Jeerapatr O. Baiyokvichit ◽  
Rasana Boonpeng ◽  
Tanapol Wongwisatekit ◽  
Pacharaporn Pattanasukwasan ◽  
...  
Keyword(s):  
Vinyl Acetate ◽  
Testing Machine ◽  
Ethylene Vinyl Acetate ◽  
Strength Test ◽  
Tear Strength ◽  
Universal Testing ◽  
Significant Difference ◽  
The Mean ◽  
Thermoforming Process ◽  
One Way Anova

The effect of thermoforming on the tear strength of ethylene vinyl acetate (EVA) mouthguard material (Bioplast®) has not been widely investigated. The present study compared the tear strengths of non-processed and processed EVA specimens in various thicknesses. Two groups of EVA sheet (non-processed and processed) in three different thicknesses of 3, 4 and 5 mm were used in specimen fabrication. The processed EVA sheets were achieved by forming the EVA sheet on the cylindrical stone model with the pressure-molding device (Biostar®). Twelve of tear strength specimens of non-processed and processed group in each thickness were prepared following the modified ASTM D 624-00 guideline. The tear strength test was conducted using universal testing machine (Lloyd® 1K series) with the speed of 500 mm/min. The mean thickness and tear strength of the non-processed and processed specimens in each thickness were compared using independent T-test. The differences in the mean tear strength for each thickness of non-processed and process specimens were determined using one-way ANOVA. The mean tear strength and mean thickness of processed EVA specimens was significantly lower than the non-processed EVA specimens for every thickness (P ≤ 0.05). There was no significant difference in the mean tear strength of EVA specimens among each thickness in both non-processed and processed groups. It can be concluded that the thermoforming process has the significant effect on the tear strength of the EVA mouthguard material formed by pressure molding device in every thicknesses. The tear strength of processed specimens were significant lower than the non-processed. Thus, it is more relevant for testing properties of the processed mouthguard material that the mouthguard material before processing.

scholarly journals Effect of black tea on the transverse strength of heat-polymerized acrylic resin

2017 ◽  
Vol 29 (3) ◽  
Author(s):  
Eni Rahmi ◽  
Zulkarnain Agus ◽  
Riezka Hanafiah Putri
Keyword(s):  
Testing Machine ◽  
Acrylic Resin ◽  
Black Tea ◽  
Test Results ◽  
Three Point Bending ◽  
Average Value ◽  
Transverse Strength ◽  
Significant Difference ◽  
Experimental Laboratory ◽  
The One

Introduction: Heat-polymerized acrylic resin is the most basic denture material used. One of the mechanical properties of an acrylic resin is its transverse strength. The transverse strength test provides an overview of the material’s durability in accepting the load at mastication. Consumption of tea, especially black tea in the world placed the second most consumed. The purpose of this study was to determine the effect of black tea on the transverse strength of heat-polymerized acrylic resin. Methods: This research was an experimental laboratory with 24 samples of heat-polymerized acrylic resin plate with the size of 65x10x2.5 mm. The sample was divided into 6 groups, each consisted of 4 samples. The first, second, and the third groups were immersed in aquadest for consecutively 1, 4, and 20 days. The fourth, fifth, and sixth groups were immersed in the black tea for consecutively 1, 4, and 20 days. The transverse strength was tested using the three-point bending method with the Universal Testing Machine. The results of the transverse strength measurement were then analyzed statistically by the One-way ANOVA test and Holm’s sequential Bonferroni posthoc test as an advanced test. Results: The results of the statistical test showed that p<0.05 (p=0.000) which means that the six groups have a significant difference in the average value of the transverse strength. Conclusion: The conclusion of this research was the black tea immersion duration was affecting the transverse strength differences of the heat-polymerized acrylic resin.

scholarly journals Pengaruh Jenis dan Volumetrik Fiber terhadap Kekuatan Transversal Reparasi Plat Resin Akrilik

2015 ◽  
Vol 1 (1) ◽  
pp. 102
Author(s):  
Pramudya Aditama ◽  
Siti Sunarintyas ◽  
Widjijono Widjijono
Keyword(s):  
Glass Fiber ◽  
Glass Fibers ◽  
Testing Machine ◽  
Acrylic Resin ◽  
Universal Testing Machine ◽  
Transverse Strength ◽  
Universal Testing ◽  
Group I ◽  
Significant Difference ◽  
Post Hoc

Resin akrilik merupakan bahan yang sering digunakan dalam pembuatan basis gigi tiruan. Kelemahan resin akrilik adalah mudah patah. Salah satu cara untuk mengatasi masalah tersebut adalah dengan menambahkan polyethylene (PE) atau glass fiber. Tujuan dari penelitian ini untuk mengetahui pengaruh jenis dan volumetrik fiber terhadap kekuatan transversal reparasi plat resin akrilik. Penelitian ini menggunakan dua puluh lima plat resin akrilik kuring panas berukuran 65 x 10 x 2,5 mm. Subjek dipreparasi untuk membuat jarak 3 mm dan sudut bevel 45o. Subjek dibagi menjadi 5 kelompok, masingmasing kelompok terdiri dari 5 subjek. Kelompok 1 (kontrol) tanpa penambahan fiber, kelompok II dengan penambahan 3,7% v/v PE fiber, kelompok III dengan penambahan 7,4% v/v PE fiber, kelompok IV dengan penambahan 3,7% v/v E-glass fiber, dan kelompok V dengan penambahan 7,4% v/v E-glass fiber. Seluruh plat direndam dalam air destilasi selama satu hari pada suhu 37oC. Pengujian kekuatan transversal plat resin akrilik dengan menggunakan Universal Testing Machine dan data yang didapat dianalisis menggunakan ANAVA dua jalur dengan tingkat kepercayaan 95%. Rerata kekuatan transversal (MPa) reparasi plat resin akrilik yang diperkuat fiber: 3,7% v/v PE fiber (67,77±3,34); 7,4% v/v PE fiber (80,37±8,42); 3,7% v/v E-glass fiber (96,72±5,43); 7,4% v/v E-glass fiber (109,44±4,98); sedangkan reparasi plat resin yang tidak diperkuat fiber menghasilkan kekuatan transversal 56,27±4,7 MPa. Hasil analisis menggunakanANAVA dua jalur menunjukkan variabel jenis dan volumetrik fiber memberikan pengaruh signifikan (p<0,05), sedangkan interaksi antara jenis dan volumetrik fiber tidak berpengaruh signifikan (p>0,05). Uji post hoc Tukey menunjukkan perbedaan signifikan (p<0,05) untuk seluruh kelompok perlakuan. Penambahan E-glass fiber dalam reparasi plat resinakrilik mampu meningkatkan kekuatan transversal lebih tinggi dibandingkan dengan menggunakan PE fiber. Peningkatan volumetrik fiber dapat meningkatkan kekuatan transversal reparasi plat resin akrilik. Effect Of Type And Volumetric Fiber On Transverse Strength Of Acrylic Resin Plate Repair. Acrylic resin is the most common denture base material. A disadvantage of acrylic resin is that it is easily fractured. One way to resolve this problem is by adding polyethylene (PE) or glass fibers. The purpose of this research is to find out about the effect of type and volumetric fiber on transverse strength of acrylic resin plate repaired. The experiment involved twenty five plates of heat cured acrylic with the dimensions of 65 x 10 x 2.5 mm. The speciments were prepared to create a 3 mm gap and 45° bevel. The subjects were divided into 5 groups; each group consisted of 5. Group I (control) was without fiber reinforcement, group II reinforced with 3.7% v/v PE fiber, group III reinforced with 7.4% v/v PE fiber, group IV reinforced with 3.7% v/v E-glass fiber, and group V reinforced with 7.4% v/v E-glass fiber. All plates were soaked in distilled water for one day at 37° C temperature. The plates were tested for transverse strength with Universal Testing Machine and all data obtained were analyzed with two way ANOVA at 95% confidence level. The mean of transverse strength (MPa) of the acrylic resin plate repair reinforced with fiber: 3.7% v/v PE fiber was (67.77±3.34); 7.4% v/v PE fiber (80.37±8.42); 3.7% v/v E-glass fiber (96.72±5.43); 7.4% v/v E-glass fiber (109.44±4.98); while the transverse strength of the acrylic resin plate with no fiber reinforced was 56.27±4.7 MPa. Two way ANOVA analysis shows that type and volumetric fiber had significant effect (p<0.05), while the interaction between type and volumetric fiber had no significant effect (p>0.05). Tukey post hoc test shows significant difference (p<0.05) for all groups. The addition of E-glass fibers in the acrylic resin plate repaired increased the transverse strength higher than that with PE fibers. The increase in volumetric fibers might improve the transverse strength of the acrylic resin plate repaired.

scholarly journals Effect of beverages on surface properties of resin-based sealants

2017 ◽  
Vol 16 ◽  
pp. 1-7
Author(s):  
Bruna Genari ◽  
Vicente Castelo Branco Leitune ◽  
João Henrique Macedo Saucedo ◽  
Susana Maria Werner Samuel ◽  
Fabrício Mezzomo Collares
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Resin Cement ◽  
Control Group ◽  
Resin Cements ◽  
Universal Testing ◽  
Halogen Light ◽  
Significant Difference ◽  
Tooth Surfaces ◽  
Light Curing

Self-adhesive, dual-polymerizing resin cements require no treatment to the prepared tooth surfaces before cementation. Aim: The aim of this study was to evaluate the influence of curing mode on bond strength (BS) of three cementing systems to bovine dentin. Methods: The buccal enamel surfaces of 50 bovine incisors were removed to expose dentin and to flat the surface. The teeth were divided into five groups (n=10), which consisted of two resin cements (Multilink and Clearfil SA Cement) that were tested in dual- (halogen light for 40 s) and self-cured modes, and a control (RelyX ARC). Two cylinders of resin cements (1.0 mm X 0.75 mm) were prepared on each bonded dentin surface. After 24h at 37oC, resin cylinders were subjected to micro-shear testing in a universal testing machine (4411/Instron - 0.5 mm/min). Data were statistically analyzed by two-way ANOVA, Tukey and Dunnett`s test (5%). Results: Multilink showed higher BS than those observed on Clearfil SA. Light-curing resulted in higher BS for both Multilink and Clearfil SA. When Multilink was light-cured, no significant difference on BS was demonstrated between it and RelyX ARC. Conclusions: The highest BS values were obtained in control group and light-cured Multilink resin cement.

scholarly journals Reconditioning of self-ligating brackets

2011 ◽  
Vol 82 (1) ◽  
pp. 158-164 ◽  
Author(s):  
Maria Francesca Sfondrini ◽  
Esmeralda Xheka ◽  
Andrea Scribante ◽  
Paola Gandini ◽  
Giuseppe Sfondrini
Keyword(s):  
Statistical Analysis ◽  
Bond Strength ◽  
Null Hypothesis ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
Shear Mode ◽  
Universal Testing ◽  
Adhesive Remnant Index ◽  
Significant Difference ◽  
Scanning Electron

Abstract Objective: To test the null hypothesis that there is no significant difference in the shear bond strength (SBS) and Adhesive Remnant Index (ARI) scores of new vs reconditioned self-ligating brackets. Materials and Methods: One hundred and twenty permanent extracted bovine teeth were embedded in resin blocks. Three different new and reconditioned self-ligating orthodontic brackets (Smart Clip [3M Unitek]; Quick [Forestadent]; and Damon3MX [Ormco]) were tested. Scanning electron microphotographs of the different new (groups 1, 3, and 5) and reconditioned (groups 2, 4, and 6) bracket bases were taken before starting the experiments. Brackets were then bonded to the teeth using an orthodontic adhesive and were then tested in shear mode using an Instron Universal Testing Machine. ARI scores were then recorded. Statistical analysis was performed to determine significant differences in SBS and ARI Scores. Results: Smart Clip and Damon3MX reconditioned brackets showed significantly lower SBS than did new ones. On the contrary, Quick reconditioned brackets showed significantly higher SBS than did new ones. No significant differences in ARI scores were found after the reconditioning process for the three different brackets tested. Conclusion: The in-office reconditioning procedure alters the SBS of self-ligating brackets, although SBS values still remain clinically acceptable.

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