Types Of Trays Research Articles

Modeling of cleaning of dust emission’ in fluidized bed building aspiration’ collector

This article describes one of the modern way to reduce dust emissions of pollutions exhausting into the atmosphere at expanded clay aggregates and other similar building materials manufactures applying filtering fluidized granular particulate material bed’ separator with low degree of dust leakage out from one. There is presented quasi-diffusion model featuring of process of cleaning of industrial emissions of dust in devices of tray type with the fluidized and weighted bed. There considered case of variable coefficient of longitudinal hashing intermixing within trough tray type separator in this article. It was made attempt to get meanings value of leakage’ degree dust out from separator. It was obtain in an implicit form. It was obtained and announced some results of the carried-out analysis are intended to get high efficiency of dust removal set up installations to clean emissions of aspiration scheme of the air environmental protection in production of bulk dispersed materials building construction industry.

Seedling-growing tray made of rice straw for maize seedling transplantation and its shear mechanics test

Abstract: The plant-made seedling-growing tray cultivation technique is an effective way to improve maize yield and quality in China’s cold northern area. However, the corn seedling nursery carrier and tray cultivation technique has been proved poor in adaptability. After comparing several nursery carriers, a design for a plant-made seedling-growing tray that is suitable for maize transplantation was proposed in which rice straw was used as the primary raw material. The preparation method, processing and structural dimensions of the tray were investigated and designed, five types of plant-made seedling-growing trays with different formulations were proposed. The shear mechanical properties and the shear strength of the plant-made seedling-growing trays were tested to determine the shear force needed for cutting through trays prepared with increasing mass ratios of rice straw and the effect of the shearing rate on the shear strength. The results showed that at a shearing rate of 100 mm/min, the maximum shear force decreased gradually as the mass ratio of straw was increased and that the hardness of the tray decreased as its shear strength decreased. Under three shearing rates (100 mm/min, 200 mm/min and 500 mm/min) and a blade displacement of 10 mm, the shear force was the highest at the point at which the tray was cut through; the required shear force to cut through the tray then gradually decreased. Trays with the same straw composition showed no significant influence of shearing rate on the tray’s shear strength at shearing rates of 100 mm/min, 200 mm/min or 500 mm/min. This study describes a multi-tray, single-strip nursery carrier for use in plant-made seedling-growing tray cultivation and proposes a theoretical basis for the design of a rotary transplanting device, the key part of a maize plant-made seedling-growing tray transplanter. Keywords: maize seedling transplanting, seedling-nursery tray, preparation, shear force, shear strength, rice straw, mixing ratio DOI: 10.3965/j.ijabe.20160906.2222 Citation: Ma Y C, Zhang W, Wang C, Mao X, Zhang B, Wang H Y. Preparation of a seedling-growing tray made of rice straw for maize seedling transplantation and its shear mechanics test. Int J Agric & Biol Eng, 2016; 9(6): 44－55.

The effect of different gas permeability of packaging on physicochemical and microbiological parameters of pork loin storage under high O2 modified atmosphere packaging conditions.

The aim of this study was to determine the influence of different packaging materials on meat quality during cold storage. Therefore pork loins (m. longissimus thoracis et lumborum) obtained from crossbred pigs (Polish Landrance x Duroc, n = 6) were stored at 2 ℃ in modified atmosphere packs (80% O2, 20% CO2) in four types of trays, which differ in gas permeability. Physicochemical (headspace gas composition, pH, colour, drip loss, cooking loss, shear force, the basic composition and fatty acid profile) and microbiological ( Salmonella spp., Escherichia coli, Enterobacteriaceae, total aerobic plates count, total psychrotrophic bacteria count, the number of lactic acid bacteria, Pseudomonas spp., the general amount of yeast and mold) parameters were monitored for up to 12 days. At the end of the storage period no differences in most physicochemical properties of pork loin due to type of packaging were found, however trays with high gas permeability had the greatest impact on total aerobic plates count and Pseudomonas spp. growth.

Neophobia in wild rats is elicited by using bait stations but not bait trays

ABSTRACTBrown rats (Rattus norvegicus) are among the most common vertebrates often becoming a major pest in urban environments. Managing rat populations is difficult, given the complex behaviours these murids can display. To help improve local control, we studied the response of wild rats to bait stations comparing baits placed on three different kinds of surfaces (on the ground, on trays and in bait stations) near burrows. We show that rats neither avoided nor preferred any tray type in particular – the latency to pick up the food pellet from the ground did not differ from the latency to pick it up from trays. However, the latency to pick the food pellet was significantly higher when food was placed in bait stations. We conclude that for effective administration of toxic baits, common bait stations are not the most effective method and should be used only in cases when placing baits directly on the ground or on a tray poses a threat to other animals and humans.

Impression Procedures for Metal Frame Removable Partial Dentures as Applied by General Dental Practitioners.

This pilot study analyzed impression procedures for conventional metal frame removable partial dentures (RPDs). Heads of RPD departments of three dental laboratories were asked to record features of all incoming impressions for RPDs during a 2-month period. Records included: (1) impression procedure, tray type (stock/custom), impression material (elastomer/alginate), use of border-molding material (yes/no); and (2) RPD type requested (distal-extension/tooth-bounded/combination). Of the 132 total RPD impressions, 111 (84%) involved custom trays, of which 73 (55%) were combined with an elastomer. Impression border-molding material was used in 4% of the cases. Associations between impression procedure and RPD type or dentists' year/university of graduation were not found.

Pressure dynamics in the trays caused by differences of the various impression materials and thickness of the relief in the maxillary edentulous model

PurposeThe purpose of this study is to compare the pressure dynamics in the trays caused by differences in the various impression materials and in the thickness of the relief provided for the trays. MethodsIn this study, two types of polyvinylsiloxane elastomers, one type of polyether elastomer and one type of alginate impression material were used. Pressure sensors were embedded at eight locations in a model of an edentulous maxilla, and used a simulation model covered with a pseudomucosa. For each impression material, the measurement was performed five times for each of the three types of trays, and the mean values were determined. Statistical analysis was carried out using one-way analysis of variance and the Tukey's HDS method, and the various pressure sensor values for each of the impression materials were compared 10s and 20s after the start of the measurement. Additionally, we compared differences among the three types of trays after 20s. ResultsThe pressure values for sensors placed in the relief region tended to become uniform. Furthermore, we saw a tendency for the pressure to increase at the alveolar crests of the first molars on the left and right and at the posterior border of the palate, all of which support the denture, when relief was provided. ConclusionsThe above results suggest that making the final impression for the denture using the selective pressure technique, with consideration given to the pressure dynamic, may lead to a good outcome in terms of preservation of the alveolar ridge.

EFFECT OF IMPLANT ANGULATION AND TRAY TYPE ON DIMENSIONAL ACCURACY OF OPEN TRAY IMPLANT IMPRESSIONS

Statement of the problem: Impression making is a critical clinical step to record accurately the three-dimensional intraoral relationships among implants, teeth and adjacent structures. Inaccuracy during impression making inevitably leads to laboratory errors resulting in lack of precision and misfit of the final prostheses. Several clinical variables may affect the precision of impression particularly in the presence of multiple angulated implants. Purpose: The aim of this study was to evaluate the effect of implant angulation and tray type on dimensional accuracy of open tray implant impressions. Materials and methods: A unilateral free end saddle dentate acrylic maxillary model resembling Kennedy class II starting from a missing canine was used in this study. Three models were duplicated from the acrylic model into epoxy resin master models. In each model, three implants were inserted in the sites of missing canine, second premolar and second molar. According to the direction of implant insertion, the master models were classified into three groups: Group 1: The three implants were inserted with 0° angulation (straight, control group). Group 2: The three implants were inserted with 15° angulation. Group 3: The three implants were inserted with 25° angulation. For all groups, open tray impressions were taken. Impressions of each group were subdivided according to the tray type into two subgroups: Subgroup A: Open tray impressions using custom made trays. Subgroup B: Open tray impressions using ready-made trays. All impressions were poured with type IV dental stone to obtain stone casts. Dimensional accuracy of the impressions was assessed using the travelling microscope. Reference distances were measured by standardized measurement protocol on the stone casts and compared with similar distances in the master models. Results: The results showed that there was a statistically significant difference between the three implant angulations. 25° angulation showed the highest mean of dimensional changes while, there was no statistically significant difference between 0° and 15° angulations in dimension II and III (P value = 0.009 & <0.001 respectively). Regarding the effect of tray type, the results showed that there was statistically significant difference in dimensional changes and the percent of dimensional changes between the two tray types in dimension III (P value = 0.019). Custom made tray showed statistically significant higher dimensional changes compared to ready-made tray. Conclusions: Impressions with ready-made trays showed less dimensional changes in case of 25° angulated implants.

Influence of Custom Trays, Dual-Arch Passive, Flexed Trays and Viscosities of Elastomeric Impression Materials on Working Dies.

Dual arch impression technique signifies an essential improvement in fixed prosthodontics and has numerous benefits over conventional impression techniques. The accuracy of working dies fabricated from dual arch impression technique remains in question because there is little information available in the literature. This study was conducted to compare the accuracy of working dies fabricated from impressions made from two different viscosities of impression materials using metal, plastic dual arch trays and custom made acrylic trays. The study samples were grouped into two groups based on the viscosity of impression material used i.e. Group I (monophase), whereas Group II consisted of Dual Mix technique using a combination of light and heavy body material. These were further divided into three subgroups A, B and C depending on the type of impression tray used (metal dual arch tray, plastic dual arch tray and custom made tray). Measurements of the master cast were made using profile projector. Descriptive statistics like mean, Standard Deviation (SD) were calculated for all the groups. One way analysis of variance (ANOVA) was used for multiple group comparisons. A p-value of 0.05 or less was considered statistically significant. The gypsum dies obtained with the three types of impression trays using two groups of impression materials were smaller than the master models in dimensions. The plastic dual arch trays produced dies which were the least accurate of the three groups. There was no significant difference in the die dimensions obtained using the two viscosities of impression materials.

Effect of variation of impression material combinations, dual arch tray types, and sequence of pour on the accuracy of working dies: "An in vitro study".

Aims:To evaluate the accuracy of dies made from dual arch impressions using different sectional dual arch trays, combinations of elastomeric impression materials, and the sequence of pour of dies.Subjects and Methods:The dual arch impression materials were grouped into three groups depending on the combination of impression materials used and each group is subdivided into four subgroups. A sample size of 8 in each subgroup yielding a total 96 impressions will be made into three groups of 32 each (Group I, II, and III). Group I constitute impressions made using monophase (M) impression material, Group II constitute impressions made using combination of heavy body and light body (HL), and Group III constitute impressions made using combination of putty and light body (PL). Dies obtained were evaluated with a travelling microscope to measure the buccolingual width of the tooth at the margin by using the sharp corners of the notches as reference points.Statistical Analysis Used:Descriptive analysis namely mean and standard deviation, one-way analysis of variance test.Results:The results obtained in this study indicate that though not statistically significant, the metal dual arch trays performed better when compared to the plastic trays in reproducing die dimensions.Conclusions:From the results obtained, dies poured from combination of heavy body and light body impressions using plastic or metal dual arch trays showed least variation in bucco-lingual dimension from master model.

Bioconversion of wheat bran for polygalacturonase production by Aspergillus sojae in tray type solid-state fermentation

Wheat bran was tested as the solid substrate for the tray-type solid-state fermentation (SSF) production of polygalacturonase (PG) enzyme by A. sojae mutant strain – a high-PG activity producer. PG production of A. sojae was found to reduce as the thickness of the substrate increase from 8 mm to 14 mm at 90% relative humidity. An interaction between the thickness of the bed and relative humidity of the environment was determined with the help of experimental design and statistical analysis tools. As a result, the PG activity could be enhanced by 31% as the process conditions optimized. Additionally, 11 mm thickness and 70% relative humidity were selected as the PG production favoring conditions with the maximum PG activity of 298 U/g substrate in tray type of SSF without the addition of any nutritive or inducing supplements into wheat bran. The kinetic study conducted in the trays revealed the presence of reduction in the water activity on the 4th day of the SSF process under stated conditions. The productivity of the process conducted under optimized conditions was 3.41 U/g substrate−1 h−1 for the 4th day of the SSF.

New Insights into the Tiwanaku Style of Snuff Trays from San Pedro de Atacama, Northern Chile

Snuff trays are conspicuous objects that are found in archaeological contexts throughout Andean South America. At San Pedro de Atacama, in northern Chile, snuff trays that exhibit iconographic motifs similar to those found on Tiwanaku megalithic monuments have been assigned to the Tiwanaku style. In the present work, we propose a new definition for this style based on the occurrence of three morphological features: an overall trapezoidal shape, incurving sides, and sharp top corners. This group includes trays with iconography from the previously defined Tiwanaku style, as well as other trays without iconography. Principal component analysis shows that Tiwanaku-style trays with and without iconography make up a single group that is significantly different from plain, largely rectangular San Pedro-style trays. The relative proportion of Tiwanaku-style trays with and without iconography does not differ between cultural periods and archaeological sites. The results point to shape as an important trait for assigning trays to styles. Furthermore, the results show that during the Middle period four main types of snuff trays were in use: Tiwanaku trays with and without iconography and local San Pedro trays, also with and without iconography. We explore the possible social implications of this co-occurrence of styles.

MODELADO DE LA CINÉTICA DE SECADO DE MANGO PRE-TRATADAS CON DESHIDRATACIÓN OSMÓTICA Y MICROONDAS

The implementation of complementary technologies such as osmotic dehydration and microwave as pre-treatments to the conventional drying process contributes to the development of new products and favors the decline of the physicochemical changes in the organoleptic and mango. The objective of this study was to evaluate the effect of osmotic dehydration with a solution at 65°Brix of 37 to 40°C for 60 min, treatment with microwave at 560 W for 7 min and combined as pre-treatments to drying flakes of handle to 70°C in an oven tray type and the sun. The samples of mango with 11 to 14°Brix and humidity 80% were sized to 1x1x0,4 cm. The weight loss and the drying time in the pre-treated showed significant differences (p 0,99) was adjusted for drying without pre-treatment and the model of Vermet et al. (R2 >0,99) for the pre-treated. The Deff for microwave and drying in an oven was higher. The flakes of handle pretreated with osmotic dehydration were the best preserved the appearance of the flakes of mango.

Simple and rapid determination of effective Murphree component efficiencies for operating absorbers, strippers and distillation columns filled with any type of trays

Estimating efficiency of an operating column has to be distinguished from that of a column being designed. This crucial point has been totally overlooked in the literature. All the methods and models available for predicting the Murphree efficiencies of tray columns have been developed for the design case. They generate their own mass and heat transfer rates and empirical parameters rather than produce true transfer rates by using operating column (realistic) data, especially the specifications of outlet streams. In addition, most of these methods are limited in application and insufficient in accuracy, especially if applied outside the range of conditions under which they were formulated.The present work introduces a general and applicable method for determining the overall Murphree component efficiencies of an operating tray column. This method uses the specifications of both inlet (feed) and outlet (product) streams of an operating column to back-calculate realistic mass and heat transfer rates for Murphree efficiency estimation. The presented method is usable to operating tray columns with any amount of flow rates and diameter as well as with any number of components and trays. Overall, it can be usable to the gas–liquid operating columns filled with any type of trays.

Comparison of disinfection protocol of irreversible hydrocolloid (alginate) impressions through plastic and metallic trays

Introduction: Many studies have evaluated the disinfection of irreversible hydrocolloid impressions through different disinfecting agents. However, impression trays can be source of cross-infection requiring disinfection. This study aimed to determine which would be the most suitable tray (metallic or plastic), available in dental market, and the ideal time to achieve disinfection by using 1% sodium hypochlorite poured into the alginate impression. Material and methods: Thirty dental impressions from the patients aged from 7-12 years and treated in the Discipline of Orthodontics of the institution were divided into two groups according to the impression tray type: 15 impressions through plastic tray (Morelli) and 15 impressions through metallic tray (Tecnodent). The material collection was performed before and after the application of 1% sodium hypochlorite for 3, 5 and 10 minutes. After the incubation period of 48 hours at 37ºC, the microorganism colonies were counted on the plates presenting from 30 to 300 colonies to determine the colony-forming unit (CFU) per mL. CFU/mL results were transformed into logarithm and submitted to statistical analysis by applying ANOVA and Tukey test (p ? 0.05). Results: Greater CFU percentage reduction occurred in alginate after three minutes, in both tray types. Concerning to tray types, it could be observed that the plastic tray showed 100% of reduction after 5 minutes while the metallic tray exhibited 81.49% of reduction after 3 minutes. Conclusion: 1 – The plastic tray showed the most effective disinfection after 5 minutes, with 100% of CFU reduction; 2 – The most effective time of disinfection with 1% sodium hypochlorite poured into the impression was 5 minutes, for both tray types.

Assessing the Magnitude and Costs of Intraoperative Inefficiencies Attributable to Surgical Instrument Trays

Efficiency in the operating room has become a topic of great interest. This study aimed to quantify the percent use of instruments among common instrument trays across 4 busy surgical services: Otolaryngology, Plastic Surgery, Bariatric Surgery, and Neurosurgery. We further aimed to calculate the costs associated with tray and instrument sterilization, as well as the implications of missing or damaged instruments. This was a single-site, observational study conducted on the surgical instrumentation at a large academic medical center in Chicago. Data were collected through direct observation by a trained investigator. Operating room instrument use and labor time required for cleaning and repacking instrument trays in central sterile processing (CSP) were analyzed using descriptive statistics and linear regression. Institutional data on volume and expenses were gathered from hospital leadership. Forty-nine procedures and 237 individual trays were observed. Average instrument (±SD)use rates were 13.0% for Otolaryngology (±4.2%), 15.5% for Plastic Surgery (±2.9%), 18.2% for Bariatric Surgery (±5.0%), and 21.9% for Neurosurgery (±1.7%). An increasing number of instruments per tray was associated with decreased use and increased instrument error rate. Using recorded labor time, the cost of cleaning and repackaging an individual instrument was calculated to be $0.10. Adding in CSP operating expenses and instrument depreciation per use, total processing cost per instrument increases to $0.51 or more. Our study demonstrates that the percent use of instruments across surgical specialties and multiple tray types is low. Attention to tray composition may result in immediate and significant cost savings.

Comparative evaluation of the accuracy of pick up transfer impressions performed with two different types of trays

The success of implant-supported prostheses is related to the passive union between the prostheses’ connections and the implants, so it is necessary to obtain an accurate working cast. Objective: To evaluate the accuracy of the transfer impressions of implants performed with individual acrylic resin trays and conventional trays using polyvinyl siloxane. Material and methods: To carry out the transfer impressions, a master cast with four external hexagon implants parallel to each other was used. Five impressions were made with individual acrylic resin trays and five other impressions with modified conventional trays, opened in the region of the implants. The linear measurements between the implants were made with a digital caliper with an accuracy of 0.01 mm and the results were statistically evaluated �(alpha = 5%)�. Results: For the points AB and BC, the measurements obtained with the individual trays were statistically similar to the master cast. For the points CD and DA no statistical differences among the three groups were observed. Conclusion: Given the obtained results and the methodology used, it can be concluded that the impressions performed with individual trays presented higher accuracy compared to the ones obtained with conventional trays.

Novel method of fabricating individual trays for maxillectomy patients by computer-aided design and rapid prototyping.

Making impressions for maxillectomy patients is an essential but difficult task. This study developed a novel method to fabricate individual trays by computer-aided design (CAD) and rapid prototyping (RP) to simplify the process and enhance patient safety. Five unilateral maxillectomy patients were recruited for this study. For each patient, a computed tomography (CT) scan was taken. Based on the 3D surface reconstruction of the target area, an individual tray was manufactured by CAD/RP. With a conventional custom tray as control, two final impressions were made using the different types of tray for each patient. The trays were sectioned, and in each section the thickness of the material was measured at six evenly distributed points. Descriptive statistics and paired t-test were used to examine the difference of the impression thickness. SAS 9.3 was applied in the statistical analysis. Afterwards, all casts were then optically 3D scanned and compared digitally to evaluate the feasibility of this method. Impressions of all five maxillectomy patients were successfully made with individual trays fabricated by CAD/RP and traditional trays. The descriptive statistics of impression thickness measurement showed slightly more uneven results in the traditional trays, but no statistical significance was shown. A 3D digital comparison showed acceptable discrepancies within 1 mm in the majority of cast areas. The largest difference of 3 mm was observed in the buccal wall of the defective areas. Moderate deviations of 1 to 2 mm were detected in the buccal and labial vestibular groove areas. This study confirmed the feasibility of a novel method of fabricating individual trays by CAD/RP. Impressions made by individual trays manufactured using CAD/RP had a uniform thickness, with an acceptable level of accuracy compared to those made through conventional processes.

The quality of working impressions for the fabrication of fixed prosthodontics prostheses (crown and bridgework)

Abstract Objective: The study was carried out to assess the quality of working impressions sent to commercial laboratories for fabrication of fixed prostheses. Materials and Methods: Impressions (n: 200) received by four dental laboratories were evaluated by two calibrated examiners. The type of work, tray designs, impression materials and techniques were recorded for each impression. Quality data on crucial details of the tooth preparations, voids at tooth preparations, tears along the finished margin line and flow of materials were documented and each criterion scored either with 2 (Good), 1 (Acceptable) or 0 (Unacceptable). The Chi-square test for independence was done for relationship analysis of the impression defects and different type of impression materials. Results: From 200 examined impressions, 53.9% were for crown works, 35.9% bridge works, 1.4% posts and cores and 8.8% for other types of work. The impression materials used were polyether (39.5%) and polyvinyl-siloxane (60.5%). The two main types of trays were metal stock (48.5%) and disposable plastic (37.5%). Impression techniques were monophase one-step technique (50.0%), putty wash two-steps technique (23.5%), putty wash one-step technique (15.5%) and dual phase one-step technique (11.0%). Overall, 64.5% of the impressions sent had unacceptable quality (0 score recorded for at least one criteria). The proportions of impression defects were significant to the type of impression materials (P &lt; 0.05). Conclusion: The percentage of unacceptable impressions (64.5%) sent to the laboratories is a serious concern, as it contributes to the inaccuracy of the crown and bridgeworks provided to patients.

Heavy trays lead to heavier meals (626.21)

The studies aimed to determine whether carrying heavier trays leads to serving more food. In our studies, participants carried trays varying in weight and served themselves food for immediate consumption. In one study (N = 91), participants carrying heavy trays served themselves more small food servings (2.87) than did participants carrying light trays (2.36 cups), p = .06. Interestingly, even heavier trays (double the added weight) eliminated the increase (2.36). In another study participants (N = 46) carried the same types of trays used in the last study. There was a significant effect of tray weight on amount served, when controlling for gender and its interaction with tray weight and item type, p = .04. Participants picked more food (40.23 grams) with the medium weighed trays than with the light trays (30.55) or the double‐weighed trays (25.55). Burden on peoples’ trays appears to lead to increased serving of food, but extra burden eliminates these effects. It is possible that some burden reduces sensitivity to weight, allowing people to serve greater quantities of food without awareness. However, too great a burden can make carrying the trays difficult, and so reduce the amount served.

Structural inspection and troubleshooting analysis of a lab-scale distillation column using gamma scanning technique in comparison with Monte Carlo simulations

In the present study, structural inspection and troubleshooting analysis of a lab-scale distillation column has been performed using gamma scanning technique and Monte Carlo simulations. MCNP4C Monte Carlo code has been used for simulations of the column and calculation of the computational density profile. The tested column is a one-pass tray type with 51cm diameter. A Cs-137 sealed source and a 1×1 inch NaI (Tl) detector has been used for this gamma scanning process. According to the results, both experimental and simulation results showed the specification of trays and another section of the column accurately. Also, in addition to the flooding and damaged tray in the column, defects such as foaming with the density of 0.17g/cm3 can be distinguished using this technique. Based on the results, using photopeak count approach the differences in the material attenuations can be better distinguished. The effectiveness of this approach in determination of malfunctions increases with the density of the material between the source and the detector. Analyzing the experimental and simulation results are indicative of the fact that the procedures and methods used in this work are quite suitable for improving the accuracy of the troubleshooting analysis based on gamma scanning technique.