Commercial Cabinet Research Articles

Impact of dry aging on quality parameters and microbiological safety of beef

The market of dry aged meat is rapidly increasing. However, few papers report the impact of specific dry aging parameters on quality and microbiological safety of dry aged meat. In this study we assessed the impact of a 90 days dry aging process, performed in a commercial cabinet, on the quality parameters and microbiological safety of Holstein beef loins. Meat pH, colour indexes and fatty acids were stable during the process. Main volatile compounds’ concentration increased over time. Any oxidation of protein residues was detected and the main proteins undergoing proteolytic degradation early in the process were myoglobin, myofibrillar constituents and sarcoplasmic enzymes. The most significant histological changes started at 30 days and striation impairment was observed, not related to oxidative processes. The total bacteria count increased without signs of spoilage, Enterobacteriaceae were not enumerated and few reads of foodborne pathogens were detected by shotgun metagenomic. These results show that when the dry aging process is performed in a dedicated cabinet under strictly controlled process parameters, the microbiological safety of the meat is preserved. Our study provides the first insights of dry aged Holstein loins, whose valorisation would certainly enhance the economic, social and environmental sustainability of the Parmigiano Reggiano food system.

Alternative mixtures to R-600a. Theoretical assessment and experimental energy evaluation of binary mixtures in a commercial cooler

This work focuses on the exploration of binary mixtures as alternative to isobutane (R-600a) from a theoretical and experimental point of view. To predict the most energy efficient blends, a theoretical model was used that analysed 5445 different blends consisting of 11 pure refrigerants. Three blends were selected for experimental testing in a commercial cabinet: R-1234ze(E)/R-600 (8/92)%mass, R-152a/R-600 (8/92)%mass and R-32/R-600 (2/98)%mass. The results of the 16-hour tests showed that, at their optimum refrigerant charge, the R-1234ze(E)/R-600 (8/92)%mass and R-152a/R-600 (8/92)%mass blends achieved energy consumption reductions of −2.69% and −5.04%, respectively, while the R-32/R-600 (2/98)%mass blend showed an increase of +0.36%. All blends reduced compressor consumption, but increased duty cycles. The results demonstrate the existence of alternative blends that can significantly reduce isobutane energy consumption with similar thermodynamic properties.

Experimental measurements of thermal–hydraulic performance of aluminum-foam water-to-air heat exchangers for a HVAC application

In this paper, thermal and hydraulic performance of in-house made prototypes of water-to-air heat exchangers are experimentally investigated and compared to those of a compact heat exchanger, used in a commercial fan-coil. The prototypes are built replacing the fins with aluminum foam surfaces characterized by a large porosity, higher than 96%. In order to evaluate the performance of the foam-based heat exchangers in a real-scale application, the geometry of the prototypes was based on that of the reference model and, moreover, experimental tests were performed placing the heat exchangers within the commercial cabinet, under the same fan power. Different bonding techniques were also tested to couple metal foams to copper tubes. Results show that similar hydraulic performance can be obtained with the foam-based heat exchangers, if compared to the commercial device. However, the large foam porosity accounts for a lower value of the surface-to-volume ratio of the aluminum foam media, thus yielding a strong penalty, up to 60%, of the heat transfer rate with respect to that of the conventional finned surface. Moreover, experimental results highlight how the bonding technique and the foam packaging have a strong influence on the contact thermal resistance and, consequently, on the overall heat transfer coefficient. Epoxy bonding allows to increase the thermal performance of the heat exchanger, if compared to press fitting, between 15% and 110%. In conclusion, results presented in this paper suggest that metal foams can be considered as a potential alternative to fins in water-to-air heat exchangers only if the foam-tube bonding is obtained by welding or brazing.

Design of a Miniaturized Printed Multi-Turn Loop Antenna for Shielding Effectiveness Measurement

This paper proposes a novel miniaturized loop antenna consisting of a multi-turn printed strip and a ring-shaped ferrite core. The lateral surface of the ferrite core is tightly wrapped by the circular multi-turn strip, which is printed on a thin, ring-shaped Styrofoam. To verify the feasibility, the proposed antenna is fabricated, and the antenna factor (AF) levels are measured using the three-antenna method from the VLF to HF band. The AF levels by measurement, theory, and simulation are 36.14 dB, 34.01 dB, and 33.6 dB at 30 kHz, respectively. In the VLF band, the antenna has a diameter of 114 mm, which is miniaturized to less than 60% compared to previous research. In addition, the proposed antenna is employed in the shielding effectiveness (SE) measurement of a small commercial cabinet to observe its suitability for SE measurement of small shielding enclosures. The SE values averaged over the frequency range from 10 kHz to 3 MHz are 5.19 dB and 14.14 dB in the horizontal and vertical polarizations.

Conversion of a Direct to an Indirect Refrigeration System at Medium Temperature Using R-134a and R-507A: An Energy Impact Analysis

This work presents the experimental evaluation of energy consumption and refrigerant charge reduction when a commercial direct expansion refrigeration system is converted into an indirect system. The evaluation (with R-134a and R-507A) used a commercial cabinet with doors for medium temperature and a single-stage refrigeration cycle using a semi-hermetic compressor and electronic expansion valve; 24-h energy consumption tests were performed at laboratory conditions for each refrigerant and configuration at three heat rejection levels (23.3, 32.8 and 43.6 °C), maintaining an average product temperature inside the cabinet of 2 °C. The work analyses the impact of the conversion on temperature and pressure indicators, as well as, in the energy performance of each element. For R-134a the refrigerant charge was reduced in a 42.9%, but the energy consumption rose by 22.0%–22.8%; for R-507A the charge reduction was of 32.8% with an increase in energy consumption of between 27.7% and 38.7%.

Bacterial presence on flexible endoscopes vs time since disinfection.

AIMTo correlate the length of endoscope hang time and number of bacteria cultured prior to use.METHODSProspectively, we cultured specimens from 19 gastroscopes, 24 colonoscopes and 5 side viewing duodenoscopes during the period of 2011 to 2015. A total of 164 results had complete data denoting date of cleansing, number of days stored and culture results. All scopes underwent initial cleaning in the endoscopy suite utilizing tap water, and then manually cleaned and flushed. High level disinfection was achieved with a Medivator© DSD (Medivator Inc., United States) automated endoscope reprocessor following manufacturer instructions, with Glutacide® (Pharmax Limited, Canada), a 2% glutaraldehyde solution. After disinfection, all scopes were stored in dust free, unfiltered commercial cabinets for up to 7 d. Prior to use, all scopes were sampled and plated on sheep blood agar for 48 h; the colony count was obtained from each plate. The length of endoscope hang time and bacterial load was analyzed utilizing unpaired t-tests. The overall percentage of positive and negative cultures for each type of endoscope was also calculated.RESULTSAll culture results were within the acceptable range (less than 200 cfu/mL). One colonoscope cultured 80 cfu/mL after hanging for 1 d, which was the highest count. ERCP scopes cultured at most 10 cfu, this occurred after 2 and 7 d, and gastroscopes cultured 50 cfu/mL at most, at 1 d. Most cultures were negative for growth, irrespective of the length of hang time. Furthermore, all scopes, with the exception of one colonoscope which had two positive cultures (each of 10 cfu/mL), had at most one positive culture. There was no significant difference in the number of bacteria cultured after 1 d compared to 7 d when all scopes were combined (day 2: P = 0.515; day 3: P = identical; day 4: P = 0.071; day 5: P = 0.470; day 6: P = 0.584; day 7: P = 0.575). There was also no significant difference in the number of bacteria cultured after 1 day compared to 7 d for gastroscopes (day 2: P = 0.895; day 3: P = identical; day 4: P = identical; day 5: P = 0.893; day 6: P = identical; day 7: P = 0.756), colonoscopes (day 2: P = 0.489; day 4: P = 0.493; day 5: P = 0.324; day 6: P = 0.526; day 7: P = identical), or ERCP scopes (day 2: P = identical; day 7: P = 0.685).CONCLUSIONThere is no correlation between hang time and bacterial load. Endoscopes do not need to be reprocessed if reused within a period of 7 d.

Virgin‐Olive‐Oil Color in Relation to Sample Thickness and the Measurement Method

AbstractColor changes of virgin‐olive‐oil samples contained in cells with different thicknesses were analyzed. Ten different commercial virgin olive oils were measured at different sample thicknesses by two methods: conventional spectrophotometry (5.0, 10.0, and 50.0 mm path length cells), and spectroradiometry (cylindrical cells with 8.0, 11.2, 15.6, 19.6, 23.2, 27.2, 36.8 and 46.4 mm internal diameters) with samples placed on the floor of a commercial cabinet using a standard daylight source. The illumination in these two methods was different, resulting in notable color differences in the samples. Color variations of virgin olive oils depending on thickness do not follow the same trend for all samples. Neither the Bouguer‐Lambert‐Beer law nor the Kubelka‐Munk theory provided successful color predictions in the whole range of thicknesses considered here. We can conclude that for precise and reproducible color measurements of virgin‐olive‐oil color, it is necessary to fix both the thickness of the sample and the illumination geometry. To achieve an easier communication between industries and/or consumers, we propose that virgin‐olive‐oil color be measured using a spectrophotometer with 5.0‐mm path length cells, for three reasons: conventional olive‐oil laboratories have spectrophotometers more often than spectroradiometers; with virgin olive oils the cleaning of 5.0 mm cells is easier than for 1.0 mm cells and it does not consume a large amount of oil; spectrophotometric signals for 5.0‐mm path length cells allow reliable measurements of even the darkest virgin‐olive‐oil samples.

Pahin de la Blancherie's Commercial Cabinet of Curiosity (1779-87)

Although Pahin de la Blancherie's Salon de la Correspondance has attracted the attention of historians and art historians alike, its character as a commercial cabinet of curiosity has never been explored. Looking at the hostility that La Blancherie engendered among the arts authorities of his time, I suggest not only that his art exhibitions encroached on territory jealously guarded by France's Royal Academy of Painting and Sculpture, but also that his penchant for displaying oddities along with his incessant wheeling and dealing jeopardized the Academy's ennobled vision of the fine arts. While the Academy waged a battle to assert the liberal arts status of painting and to distinguish works of art from crafts and curios, La Blancherie exhibited paintings and sculptures along with two-headed calves, anatomical models, and the latest fashions in combination locks. In another contrast, the Academy preserved its class status by barring members from engaging in commerce, whereas La Blancherie sold his wares openly and promoted himself in the unmistakable tones of a huckster. Finally, as the arts administration planned to establish a permanent exhibition of Old Master paintings in the renovated halls of the Louvre Palace, La Blancherie mounted his own show of French masters, which he embellished with characteristic self-promotional flair. For the Academy's defenders, this ambitious exhibition was the last straw.

Vinyl foam: A viable substitute for wood

Rigid vinyl foam offers fabricators a maintenance-free alternative to wood. It is suitable for both internal and external uses, and unlike wood, vinyl foam products will not rot, warp, or peel, and will never need painting. In order to thoroughly evaluate potential applications for foam PVC, samples were provided to a commercial cabinet manufacturer to obtain his perspective of pertinent properties and potential applications. Results of this evaluation are presented along with processing and formulation recommendations for making good-quality PVC foam.

Vinyl foam: A viable substitute for wood

AbstractRigid vinyl foam offers fabricators a maintenance‐free alternative to wood. It is suitable for both internal and external uses, and unlike wood, vinyl foam products will not rot, warp, or peel, and will never need painting. In order to thoroughly evaluate potential applications for foam PVC, samples were provided to a commercial cabinet manufacturer to obtain his perspective of pertinent properties and potential applications. Results of this evaluation are presented along with processing and formulation recommendations for making good‐quality PVC foam.

A Simple Low Volume Laboratory Research Spray System

Commercially available cabinet sprayers are not well suited for making low volume applications (<30 L/ha) of herbicides to woody forest species that can be up to 1.5 m tall. A simple, inexpensive laboratory sprayer that overcomes some limitations of commercial cabinet sprays can be built from materials readily available at local building and electronic suppliers. The only specialized equipment required is a positive displacement pump and a rotary disk atomizer. The atomizer is attached to the end of a variable height arm mounted on a laboratory cart. A positive displacement pump ensures controlled flow. The operator pushes the cart along a metal rub rail which keeps the cart tracking in a straight line. Travel speed is regulated by the operator following a marker on a clothesline-like loop of fishing line and is driven by a variable-speed drill attached to a variable voltage power supply.

Development of a laminar air-flow biological cabinet.

Abstract Engineering and microbiological tests indicated that a typical, commercially available laminar flow cabinet was not effective in providing both product protection and agent containment. An analysis was conducted of the air flows within the cabinet and at the cabinet face, and design criteria were established. Several configurations were proposed for an actual air-flow evaluation in a mock-up unit. The configuration selected was evaluated for product protection and agent containment using controlled bacterial and viral aerosols. The aerosol challenges generated during these evaluations were considerably higher than normal in order to provide stringent test conditions. Test results indicated that the mock-up unit provided considerably better product protection than the commercial cabinet, and agent containment was improved. Based upon the results obtained in this study, detailed design drawings were prepared.

Microbiological studies on the performance of a laminar airflow biological cabinet.

Engineering and microbiological tests indicated that a typical, commercial laminar airflow cabinet was not effective in providing either product protection or agent containment. The cabinet was modified and tested through a series of alternate configurations to establish a set of design criteria. A mock-up cabinet was developed from these design criteria. The mock-up unit was evaluated for efficiency in providing both product protection and agent containment. In these evaluations, challenge methods were developed to simulate normal, in-use laboratory operations. Controlled bacterial or viral aerosol challenges were used at higher than normal levels to provide stringent test conditions. Test results indicated that the mock-up unit was considerably better in preventing agent penetration (0.1 to 0.2 particles per 100 ft(3) of air) than the commercial cabinet (5 to 6 particles per 100 ft(3) of air) during product protection tests. Similarly, agent containment was considerably better in the new cabinet (particle escape of 2 to 3 per 100 ft(3) of air at only one of the five test sites) than in the commercial cabinet (particle escape of 2 to 14 per 100 ft(3) of air at three of the five test sites).

Microbiological Studies on the Performance of a Laminar Airflow Biological Cabinet

Engineering and microbiological tests indicated that a typical, commercial laminar airflow cabinet was not effective in providing either product protection or agent containment. The cabinet was modified and tested through a series of alternate configurations to establish a set of design criteria. A mock-up cabinet was developed from these design criteria. The mock-up unit was evaluated for efficiency in providing both product protection and agent containment. In these evaluations, challenge methods were developed to simulate normal, in-use laboratory operations. Controlled bacterial or viral aerosol challenges were used at higher than normal levels to provide stringent test conditions. Test results indicated that the mock-up unit was considerably better in preventing agent penetration (0.1 to 0.2 particles per 100 ft(3) of air) than the commercial cabinet (5 to 6 particles per 100 ft(3) of air) during product protection tests. Similarly, agent containment was considerably better in the new cabinet (particle escape of 2 to 3 per 100 ft(3) of air at only one of the five test sites) than in the commercial cabinet (particle escape of 2 to 14 per 100 ft(3) of air at three of the five test sites).

A New Type of Microscope-Slide Cabinet

A general requirement of most biological research laboratories is suitable compact storage space for microscope slides. This is particularly true where space is required for storing deeper preparations such as whole mounts in a horizontal plane with their identification labels in full view. Of the many commercial cabinets now available few appear to be entirely satisfactory. Although some are constructed to hold the slides horizontally, in these the slide holders are in the form of trays with a capacity of not more than one dozen slides and the trays are carried in grooves nne above the other. In others, thin drawers are used in which the slides are laid side bv side on the bottom. In the former, considerable handling is required to expose the labels of the slides. In the latter, slides easily become disarranged, and are exposed to an accumulation of dust; and though considerable space is required, the capacity of the drawers in most cases is limited to less than 100 slides. A cabinet in which a number of desirable features is incorporated has recently been developed at this laboratory, and a description of it constitutes the basis of the present paper.