Conventional Trays Research Articles

Imcube: A static particle size analyzer for all shape types via advanced vision tools and integrated machinery

An integrated machinery to perform the analysis of particle size distribution through image processing formulations is presented. The product is comprehensive and flexible to many different industrial needs with a tailored hardware integration and design, which employs a set of sophisticated algorithms for the computational efficiency and accuracy. Compared to the traditional methods, the architecture is superior and provides significant impact as irregular and noncircular particles from a wide dimension spectrum can be analysed instantly, eliminating the need for significant manual effort with conventional trays with low accuracy. The reports are obtained through the built-in screen, mounted on the device, at customer specified detail level in addition to state-of-the-art presentations benefiting common statistics. The prediction performance, which is validated through industrial data, can further be developed for smaller particles, as a higher resolution camera implementation is necessary, with a heuristic algorithm to estimate the maximum likelihood of particle sizes when they overlap on the measurement tray.

Novel distillation column retrofit combining energy integration and different tray designs

This study introduced an innovative approach for energy integration of distillation columns using side heat exchangers and parastillation. The traditional installation of side heat exchangers typically demands additional stages or an increased reflux ratio to maintain the desired separation. Here, parastillation trays replace the conventional trays below the side-reboiler or above the side-condenser. These trays enable the inclusion of more theoretical trays within the same column height compared to conventional technique. This strategic implementation allows achieving the desired separation while using energy integration and keeping the column height and reflux ratio unchanged. A comprehensive case study demonstrates how this approach effectively surpasses the limitations of existing methods. Detailed analyses of thermodynamics and exergy loss emphasize its benefits. A practical case study focusing on bioethanol purification confirms its industrial viability. This pioneering technique presents a promising solution for sustainable chemical processes, particularly advantageous for energy-intensive processes such as dilute bioproduct separation.

Chairside 3-D printed impression trays: a new approach to increase the accuracy of conventional implant impression taking? An in vitro study

PurposeA high transfer accuracy of the intraoral implant position to a model is required, to manufacture implant-supported restorations. However, clinically relevant deviations persist between the intraoral implant position and the model obtained, even for the benchmark conventional custom implant impressions with polyether. Thus, new approaches using 3-D printed impression trays may increase the transfer accuracy of implant impressions. The ability to adjust parameters such as the thickness of the layers and the influence of the openings in the impression tray could potentially affect accuracy.MethodsFour different types of impression trays (n = 10 for each group) for the conventional impression technique were investigated: conventional custom impression tray, customized foil tray, chairside 3-D printed impression tray with the SHERA system, and the Primeprint system using an implant master model with four implants in the posterior region and a reference cube. After plaster model casting, all models were measured using a coordinate measuring machine, and the deviation from the reference dataset was determined. A statistical ANOVA analysis was performed (p < 0.05).ResultsChairside 3-D printed impression trays showed the best results, followed by conventional custom impression trays. Implant impressions obtained using a customized foil tray exhibited the lowest accuracy. Statistically significant differences were observed between 3-D printed impression trays and conventional custom impression and customized foil trays (p < 0.05). Whereas, the implant position did not have any significant influence on accuracy (p > 0.05).ConclusionsChairside 3-D printed impression trays significantly increase the transfer accuracy for implant impression taking.Graphical

Dimensional Stability and Retention Strength of Impressions to Custom Impression Trays Fabricated Using Conventional Method and Additive Technology - An In-vitro Study.

3D printing technology is replacing manual fabrication in all fields. 3D-printed impression trays should be assessed as they could replace conventional impression trays in the future. In-vitro comparison and evaluation of the dimensional stability and retention strength of impressions to custom impression trays fabricated using conventional method and additive technology. A maxillary edentulous auto-polymerizing acrylic resin model served as the master model. Two moulds were prepared from the master model in order to obtain 12 casts. One cast was scanned for 3D printing digital light processing (DLP) and fused deposition modelling (FDM) 24 impression trays using polylactic acid (PLA). Twelve casts were used to fabricate light cure impression trays. Polyvinyl-siloxane impressions were made on the master model using 36 impression trays and 18 trays each were used to assess dimensional stability and retention strength. In dimensional stability analysis, one sample t-test revealed a statistically significant difference between each group and the master model followed by a one-way ANOVA. There were significant differences, but the difference was less with FDM trays (P < 0.05). In retention strength analysis, one-way Analysis of variance (ANOVA) revealed statistically significant difference between each group and post-hoc test revealed specific difference, the highest with FDM trays (P < 0.05). Dimensional changes were observed at 30 minutes and 72 hours. Lesser dimensional changes were observed when impressions were made using FDM trays followed by DLP and light cure trays. The mean retention strength seen in descending order was FDM, followed by DLP and light cure trays. The best retention strength was noticed when impressions were made using FDM trays.

Use of digital tools for preclinical training in complete denture: A pilot study.

Advances in CAD-CAM complete dentures open up opportunities in preclinical laboratory education. A cross-over study was conducted to assess the benefit of digital training in custom tray fabrication. Hypotheses were that digital training improved conceptual skill acquisition and that assessment of digital work helps in the discrimination of students' difficulty. Third-year students were allocated either into group A and took the manual practical classes before the digital ones, or into group B (N = 154). Prior to the sessions, a motor skill test was conducted. The influence on the learning process was evaluated by comparing the groups' results to the manual lab work with a Student's t-test. The effectiveness of the assessment in discriminating manual aptitude and conceptual skill was studied through Spearman's rank coefficient between digital and manual scores in conceptual skill and with a subgroup analysis according to the results of the motor skill test. The level of significance was set up at .05. Students' satisfaction was also assessed with a questionnaire. Students in group B achieved better scores. Spearman's rank coefficient test showed a weak correlation, R = .16. For manual lab work, the most manually skilled students did significantly better. In contrast, for the digital session, the medium manually skilled students did better. More than half of the students (55%) found the manual and digital sessions complementary, without identifying any difference depending on the learning sequence. Digital training improved the students' results in the conventional practical exercise. Assessments of the digital and conventional custom trays were complementary in order to distinguish conceptual and motor skills.

Influence of different bio‐based and conventional packaging trays on the quality loss of fresh cherry tomatoes during distribution and storage

AbstractThe quality loss and shelf life of cherry tomatoes stored in different types of commercially available bio‐based packaging trays were analysed and compared with the reference materials, corrugated cardboard and recycled polyethylene terephthalate (rPET). During storage under conditions reflecting points in a regional German supply chain, typical quality parameters were investigated. Surface bacterial counts of the packaging materials were investigated before and after storage, and material parameters were determined for selected packaging.The results showed that groundwood pulp and sugar cane trays showed higher preserving characteristics of tomatoes in comparison with the references. During storage, weight loss was highest for tomatoes stored in polylactic acid (PLA). The highest increase in microbial count with 3.5 log10 units was observed after 20 days for tomatoes stored in packaging trays of bamboo. The lowest increase with 0.5 log10 units and 0.6 log10 units was recorded for tomatoes stored in packaging trays of groundwood pulp and grass paper, respectively. The results of the packaging parameters show the highest (411.0 N) and lowest (79.0 N) tensile strength for cellulose and groundwood pulp. The water absorption capacity ranged from &lt;10 g/m2 (bamboo, cellulose) up to 211.2 g/m2 (corrugated cardboard).

Standardised colour-coded compartmentalised syringe trays improve anaesthetic medication visual search and mitigate cognitive load

BackgroundAnaesthetic procedures are complex and subject to human error. Interventions to alleviate medication errors include organised syringe storage trays, but no standardised methods for drug storage have yet been widely implemented. MethodsWe used experimental psychology methods to explore the potential benefits of colour-coded compartmentalised trays compared with conventional trays in a visual search task. We hypothesised that colour-coded compartmentalised trays would reduce search time and improve error detection for both behavioural and eye-movement responses. We recruited 40 volunteers to identify syringe errors presented in pre-loaded trays for 16 trials in total: 12 error present and four error absent, with eight trials presented for each tray type. ResultsErrors were detected faster when presented in the colour-coded compartmentalised trays than in conventional trays (11.1 s vs 13.0 s, respectively; P=0.026). This finding was replicated for correct responses for error-absent trays (13.3 s vs 17.4 s, respectively; P=0.001) and in the verification time of error-absent trays (13.1 s vs 17.2 s, respectively; P=0.001). On error trials, eye-tracking measures revealed more fixations on the drug error for colour-coded compartmentalised trays (5.3 vs 4.3, respectively; P<0.001), whilst more fixations on the drug lists for conventional trays (8.3 vs 7.1, respectively; P=0.010). On error-absent trials, participants spent longer fixating on the conventional trials (7.2 s vs 5.6 s, respectively; P=0.002). ConclusionsColour-coded compartmentalisation enhanced visual search efficacy of pre-loaded trays. Reduced fixations and fixation times for the loaded tray were shown for colour-coded compartmentalised trays, indicating a reduction in cognitive load. Overall, colour-coded compartmentalised trays were associated with significant performance improvements when compared with conventional trays.

The Effectiveness of Dental Bleaching during Orthodontic Treatment with Clear Aligners: A Systematic Review

The objective of this article was to systematically review the literature to determine how effective tooth whitening procedures are when carried out in tandem with orthodontic clear aligners. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Online searches of PubMed, Medline via Ovid, Science Direct, the Cochrane database of systematic reviews via Ovid, Scopus, and Google Scholar as well as manual searches of the references of the selected articles were conducted. Clinical studies which assessed the efficacy of dental bleaching using orthodontic clear aligners were included in the present study. Data from the included studies were extracted and assessed for risk of bias using the Cochrane risk of bias tool. Three studies met the inclusion and exclusion criteria and were included in this study. One study compared the efficiency of tooth bleaching between clear aligners and conventional bleaching trays. One study evaluated the effectiveness of dental bleaching using clear aligners by comparing the tooth shade of those patients to a control group of patients who did not receive dental bleaching during orthodontic clear aligner treatment. One study evaluated the effectiveness of different concentrations of different bleaching agents using clear aligners. All the included studies showed an improved tooth shade when using clear aligners as bleaching trays.

Accuracy of indirect bonding trays - a measurement algorithm.

To present an image-processing measurement algorithm to evaluate the transfer accuracy of indirect bonding (IDB) trays, exemplified by a CAD/CAM-based IDB tray integrated into a digital orthodontic workflow. Plaster casts of 24 patients with full dentition and different malocclusions were scanned with an intraoral scanner (Trios; 3Shape, Copenhagen, Denmark) to obtain digital models, which served for the virtual placement of orthodontic brackets in simulation software (OnyxCeph; Image Instruments, Chemnitz, Germany). The resulting STL files were sent to a dental laboratory (CA Digital; Hilden, Germany) for the production of INDIVIDUA IDB trays. These trays were used to transfer the brackets to the respective plaster casts. Finally, a second scan was performed to record the actual bracket positions. The transfer accuracy was then analyzed by a measurement algorithm scripted to automation, which calculated the deviations of the planned and real bracket positions with a local best-fit alignment, resulting in three linear and three angular measurements for each bracket. In total, 622 brackets and tubes were transferred successfully. The presented algorithm analyzed the transfer accuracy and demonstrated that the linear measurements were 98.3% within the range of the American Board of Orthodontics standard. The angular measurements were 86.7% within this range when the INDIVIDUA IDB tray was used. Scripted measurement algorithms facilitated the evaluation of present and future materials and designs for IDB trays to obtain an efficient solution for orthodontic practice. The INDIVIDUA IDB tray is a digital alternative to conventional IDB trays (Int J Comput Dent 2022;25(3):295-302; doi: 10.3290/j.ijcd.b2599775).

Evaluation of a novel 3D-printed custom tray for the impressions of edentulous jaws

PurposeThe purpose of this study was to evaluate a novel 3D-printed custom tray for impressions of edentulous jaws, and to compare it with conventional impression trays. MethodsFifteen edentulous patients were enroled to evaluate the accuracy and border extension of a novel custom tray in the shape of a complete denture. Four impressions were made for each patient. Impressions made using novel custom trays were considered the experimental group, impressions made using conventional custom trays were considered the control group, and impressions made using final dentures and non-pressure custom trays were considered the reference groups. The experimental and control groups were compared with the reference groups using three-dimensional (3D) comparison analysis, and the impressions were further divided into regions. The root mean square (RMS) value was calculated to analyse the differences in impression morphology. Additionally, the experimental and control groups were compared to analyse border extension at standard locations. ResultsCompared to the final denture impression as a reference, the diagnostic denture impression (RMS:0.146 ± 0.024 mm) was closer to the reference than the conventional impression (RMS:0.176 ± 0.047 mm), with a significant difference only in the secondary stress-bearing area. The border extension of the diagnostic denture impression was slightly longer than the conventional impression; however, the difference was not statistically significant. ConclusionsThe impressions made using the novel custom tray were similar to those made with a definitive complete denture. However, no significant differences were noted when compared with the conventional impressions.

Accuracy and feasibility of 3D-printed custom open trays for impressions of multiple implants: A self-controlled clinical trial

Statement of problemThree-dimensionally printed custom open trays have become a popular option in clinical implant dentistry because of advantages such as individualization, efficiency, and effectiveness. However, clinical evidence on their accuracy and feasibility is lacking. PurposeThe purpose of this clinical study was to evaluate the accuracy and feasibility for impressions of multiple implants by using 3D-printed custom open trays versus conventional custom open trays. Material and methodsTwenty-two partially edentulous individuals needing impression making for restorations supported by multiple implants were enrolled. Two types of custom open trays were made for each participant, a 3D-printed tray (test) and a conventional tray (control). With a splinted technique, silicone definitive impressions were obtained with the 2 custom open trays and poured with Type IV dental stone. Impression accuracy (primary outcome) was evaluated by measuring linear distances and the marginal gaps between the implant replicas and verification devices on the test and control casts. Clinical tray fit, impression quality, and cast quality were rated by an independent technician through a visual analog scale (VAS). The fabrication time and cost of the 2 types of custom open trays were recorded. The feasibility of 3D-printed trays was determined from these outcomes. The paired Student t test and Wilcoxon rank-sum tests were used for statistical analysis (α=.05). ResultsFor impression accuracy, no statistically significant difference was found between test and control groups (P>.05). In terms of clinical tray fit, impression quality, and cast quality, no statistically significant difference was found (all P>.05). Regarding fabrication time and cost, the test group (57.65 ±6.49 minutes, 0.37 ±0.07 United States dollars [USD]) exhibited superiority over the control group (101.96 ±2.92 minutes, 4.41 ±0.37 USD) (both P<.001). ConclusionsWithin the limitations of this study, the 3D-printed custom open trays were clinically accurate, efficient, and cost-effective for impressions of multiple implants.

Parastillation and metastillation applied to bioethanol and neutral alcohol purification with energy savings

Bioethanol is an important biofuel with high potential to be a safety environmental alternative to fossil fuels. However, bioethanol production involves many distillation steps, which is one of the most energy consuming separation processes. Unconventional distillation techniques were proposed, aiming to reduce energy cost and CO2 emissions on bioethanol production. Parastillation and metastillation processes and novelty combinations of these techniques were explored. In all proposed configurations the liquid or vapor phase was divided inside the column. For the first time, parastillation columns with multiple condensers and columns with different distillation techniques combined into one unique column shell, here denominated as combined columns, were studied. Multiple condensers set, in parastillation columns, avoids the non-necessary mixed of the vapor phases. Combined columns are composed of parastillation trays in the rectifying section and of metastillation or conventional trays in the stripping section. The new configurations reduce total annual costs and CO2 emissions up to 35 % and 42 %, respectively, when compared with traditional distillation. Reduction in the column diameter by using metastillation instead of conventional distillation was possible without an increase in the column height, differently from previously results. Therefore, biofuel and neutral alcohol production can be even more economical and sustainable.

In vitro evaluation of the application of digital individual tooth tray in the impression making of mandibular full-arch crown abutments

Objective To establish a method for the production of digital individual tooth tray based on three-dimensional (3D) scan, computer-aided design (CAD) and 3D printing, and to evaluate the effect of impression taking of full-arch crown abutments by digital individual tooth tray technique and conventional method through in vitro study. Methods The full crown preparation was performed on all the fourteen resin teeth in a standard model of mandibular dentition. The surface data of prepared abutments was collected by 3D scanning. A new project was created in a dental CAD software including all the fourteen teeth in the mandibular dentition. The design modules of anatomy crown and coping were selected for each tooth. The dentition was divided for three sections: right posterior teeth, anterior teeth, and left posterior teeth areas. The connector design was added between the abutments within the same section. The scanned data of the abutments were imported. The occlusal plane and insertion path were determined. The position of margin line, as well as the shape of anatomy crown and connector as the main body of the individual tooth tray were designed for each abutment. The shape of coping was generated as the space for holding the impression material. The finalized data of the main body was imported into Geomagic software. The retentive attachment was added at the external surface and the tissue stop was formed at the internal surface. The completed individual tooth tray was manufactured by 3D printing with resin material. The data of full-arch crown abutments were modified and printed. The conventional dentition trays A and B, as well as digital individual tooth tray were designed and printed for four copies each. The polyether impressions of the full-arch abutments were made by conventional one-step method using dentition tray A, and by sectional-impression technique using digital individual tooth tray and dentition tray B for four times each. The time spent for each impression taking and the numbers of defects at the shoulder and axial/occlusal surface in each impression were recorded. The impression quality of each abutment was evaluated. The overall quality distribution and the pass rate of abutments between the two methods were analyzed. Results The impressions made by conventional method had more defects at shoulder than those made by digital individual tooth tray technique. No difference of the number of defects at axial/occlusal surface between the two methods was observed. The digital individual tooth tray technique for the full-arch abutment impression exhibited higher pass rate of abutments and better quality of impression, compared with conventional methods. Conclusion A new method for the production of digital individual tooth tray based on digital scanning, CAD and 3D printing was established. Compared with conventional method, using digital individual tooth tray technique for impression taking of full-arch abutments can achieve better effect.

Experimental Fluid Dynamics Study of a New Fractal Dual-Flow Tray

Countercurrent flow in conventional dual-flow trays results in segregation in liquid and vapor flow, reducing tray efficiency. Therefore, a new dual-flow tray with fractal geometry was experimental...

(Invited) Advances in Prussian Blue Batteries for Behind-the-Meter Applications

There is an increasing demand for high power, long cycle life, inexpensive batteries for behind-the-meter (BTM) applications including uninterruptible power supplies (UPS), demand charge management, and electric vehicle (EV) fast support. For the past decade most battery manufacturers have focused on increasing energy density while decreasing the cost of cells optimized for EVs, which are not designed for BTM duty cycles. Innovations in materials and design to enable higher power and longer cycle life at a low cost have received little attention. This presentation introduces a new battery technology based on cells containing Prussian blue electrodes and an organic sodium-ion electrolyte. Prussian blue (ferric hexacyanoferrate) is a pigment found in a variety of consumer products. Prussian blue and its transition-metal substituted analogues have a unique open framework crystal structure containing channels and interstices larger than de-solvated sodium ions. This allows sodium ions to be inserted and removed from the Prussian blue structure rapidly and reversibly with near-zero strain to the structure.1 For device performance to benefit from these unusual characteristics, both of the two electrodes in the cell must have comparable rate capability and cycle life. For this reason, Natron Energy has developed a cell in which the cathode and anode active materials are both Prussian blue analogues. The cathode undergoes a single electron redox of FeIII/II(CN)6 at +0.9 V vs. S.H.E., while the anode undergoes a unique MnII/I(CN)6 redox at -0.7 V vs. S.H.E. in which a unique low-spin Mn(I) valence state forms during charging.2 The resulting cell has a nominal voltage of 1.6 V, can be fully discharged at rates of up to 50C, and fully recharged at rates of up to 16C. Because the cathode and anode each undergo low-strain single phase reactions, neither electrode limits the life of the cell. After over one year of 10C-10C cycling (60,000 cycles), just 2% capacity loss is observed. The high power and long cycle life of the Prussian blue cell lead to new opportunities for pack and system design optimization. This presentation will highlight two real-world examples of BTM applications that make use of these device properties: data center UPS, and EV fast charge support. The high rate capability of the Prussian blue cell allows rack-mounted UPS battery trays based on this chemistry to deliver nearly double the power density of conventional lead acid trays. In addition, a simulation of energy storage photovoltaic (PV) solar system sizing was performed for electricity cost minimization for a four-charger direct current fast charge (DCFC) station using one year of real-world operational load data. The dynamic rate capability and deep discharge cycle life of the Prussian blue battery allows a smaller, lower cost system to deliver a competitive return on investment. These two examples indicate the potential value of high rate capability and long cycle life for BTM applications.

Evaluation of different impression techniques for indirect e-max fixed dental prostheses. Randomized clinical trial

IntroductionNowadays, it is a new era in prosthetic dentistry, due to the use of digital impressions and new digital computer-aided methods for designing and manufacturing computer-aided design/computer-aided manufacturing (CAD/CAM). Now, we are trying to change all the old traditional methods to have better results. Some studies found that there is no significance between the overall survivals of the tooth supported and implant CAD CAM fabricated prostheses. In addition, there is no difference in accuracy. Making single crowns or short span bridges can be done efficiently with digital impressions. In addition, it was found that digital impressions could be more reproducible. Materials and methodsThis randomized clinical study evaluated three impression techniques. Ten participants demanding three units all-ceramic bridges were involved in the study. The inclusion criteria were from 18 to 60 years group age; the patient should have plaque score and bleeding score <25%, with good periodontal state, with one missing tooth in need to three units fixed dental prosthesis, with sound or properly restored neighboring and opposing teeth. Sequencing of the different impression techniques investigate is determined according to computer-generated randomization list. The sequence of the different impression techniques was concealed by sealed envelopes until the date of the participant clinical visit. Three operators (R.A, M.M, and R.G.) Performed the impressions. ResultsAlmost 50% of the participants were male and the rest were female, with mean age 37.3 from range (from 20 to 50). Impressions were made to abutments of three units bridges. The mean of the procedure time ± SD was 336 ± 9.4 s for closed mouth technique impressions, 557 ± 8.2 s for the single-step traditional metal tray technique, and 397 ± 8.6 s for the Omnicam [Table 1]. ConclusionsIt was found in our research that the closed mouth technique is the fastest, with best patient acceptance and best operator easiness evaluation followed by the digital procedures, which are preferred over the conventional trays as approved by the previous studies in the literature.

Bactericidal paper trays doped with silver nanoparticles for egg storing applications

In this study, a cost-effective way to deposit the silver nanoparticles (AgNPs) on paper egg trays was developed, which proved suitable for prolonged storage of table eggs for house-hold use without deterioration of egg quality. Silver nanoparticles were synthesized based on chemical reduction approach and mixed with gelatin–chitosan mixer used as a colloidal stabilizer as well as fixing agent. AgNPs-doped paper egg trays were characterized by TEM, SEM, FTIR, EDX and XRD. AgNPs containing egg trays were tested for its bactericidal effect against commonly found bacteria on egg shells, E. coli, S. aureus, Streptococcus spp and Salmonella spp. Storing of eggs in the AgNPs-deposited paper egg trays improved the shelf-life of the eggs by more than 14 days compared to controls (eggs stored in conventional trays). In conclusion, the developed paper trays possessed strong antimicrobial activity and it could be an effective storage material for eggs.

New Realization of Periodic Cycled Separation

A new realization of periodic cycled gas/liquid separation is presented. Separation factors and column efficiencies are compared for a column stripping ammonia from water with air, using three different sets of internals: conventional sieve trays, Sulzer BX gauze packings, and periodically cycled trays. The proposed new periodic trays are shown to be advantageous compared to their continuous alternatives. It is demonstrated experimentally that periodic tray efficiencies of up to 300% are achievable. With the proposed new tray design, a new operation form is also introduced in which the trays are drained sequentially rather than simultaneously, such that the vapor flow is not interrupted during the liquid drainage. For different ratios of counter-current vapor/liquid flow rates, column efficiencies for periodically cycled columns are shown experimentally to be two times greater than those for columns with sieve trays.

Innovative Replication and Recuperation of Complex Torus Palatinus: A Prosthodontic Case Report

ABSTRACT The prevalence and morphological appearance of torus palatinus has been well documented in the literature. However, adequate literature regarding the precise impression technique and rehabilitation of edentulous maxillary arch with torus is less. Intraoral growths present challenges when trying to capture exact details for impressions starting from the primary to the final stage since the complete seating of conventional impression trays is not possible. In addition, the ability to withstand occlusal loading is compromised as the mucosa tends to be thin. As the extensions of these bony growths can vary, the design of the prosthesis should be optimal to give adequate retention and stability to the prosthesis. Although customized disposable trays are available, they are not cost effective and involve a complex armamentarium. This case report presents a modified impression technique where optimal accuracy was achieved with a design framework having better retention and stability of the final prosthesis. How to cite this article Rajeev V, Arunachalam R. Innovative Replication and Recuperation of Complex Torus Palatinus: A Prosthodontic Case Report. World J Dent 2016;7(4):208-212.

Design, fabrication and performance evaluation of solar dryer for banana

An indirect, active-type, environmentally friendly, low-cost solar dryer was designed to dry various agricultural products. The dryer was built by locally available, biologically degradable, low-cost materials. The dryer consists of solar flat plate air heater with three layers of insulation, drying chamber and a fan with a regulator to induce required air flow in the system. Banana is the chosen crop for the experimentation since it is high in production and also has substantial loss in India. Also, dried bananas are having good nutritive value which makes it as essential diet. The experiments were conducted to dry banana slices and to study its drying characteristics like rate of drying and quality of dried banana in terms of taste, colour and shape. The dryer has the following features: two different air flow configurations (air flow between glass cover and absorber plate called as the top flow and air flow between absorber plate and the bottom insulation of solar collector called as the bottom flow), forced flow with variable flow rates from 0–3 m/s and two different mounting schemes (conventional trays and wooden skewers). In the top and bottom flow experiments, the bottom flow provided about 2.5 °C higher chamber temperatures than the top flow for the same solar energy input. The efficiency of top flow configuration was found to be 27.5 %, whereas the efficiency of bottom flow configuration was found to be higher at 38.21 %. The results also agree well with the theoretical calculations performed as 60 W of energy can be saved for the same energy input. The drying rate was found to increase when wooden skewers were used instead of conventional trays. At the end of the day, the total difference in moisture content is found to be 3.1 % which is considerable knowing that the rate of drying drastically decreases with time. Banana dried at 1 m/s air flow rate was of the best quality in terms of colour, taste and shape when compared to drying at 0.5 and 2 m/s air flow rate while the weather condition and ambient conditions were almost the same for all the cases with negligible difference.