Development of a Universal Scale for Validating the Process of Sanitization of Equipment, Materials and Surfaces in the Animal Facility

Background: Monitoring of sanitization of cage equipment is an essential function of any laboratory animal facilities, seeking to ensure the animal health and welfare. The purpose of the current study was to develop universal scale for monitoring sanitization through detection of residual ATP for the most effective process of sanitizing components of rodents micro- and macro-environment. Methods: Sterile pens and swabs for the HY-LiTE® Luminometer Instrument were used to measure ATP concentration (RLU) on the cleaned surface samples. We have examined the elements of the microenvironment (rodent and rabbit cage, cage wire meshes, feed separating pieces, water bottles with tips, houses, tunnels, IVC cage frames, cage tops and cage wire meshes). The assessed swab area on each of the surfaces was 10×10 cm. Result: We observed, that combined washing (cleaned manually and with automatic universal washers with detergent) gives the lowest RLU values. Monitoring of the quality of sanitization of equipment and surfacescan be carried out without the use of microbiological tests. Use of pre-washing allows increasing the service life of caging equipment. We have developed an assessment scale to monitor sanitizing, which can be recommended to scientific and breeding animal facilities for monitoring sanitization cage equipments.

A Novel and Inexpensive Technique for High-tension Tendon Clamping with Expandable Mesh Sleeving for in Vitro Foot Biomechanics Testing

In vitro biomechanical testing is common in the field of orthopedics when novel devices are investigated prior to human trials. It is typically necessary to apply loads through tendons to simulate normal activities, such as walking during a foot and ankle study. However, attachment of tendons to linear actuators has proven challenging because of the tendency of clamps to either slip off or rupture the tendon. Freeze clamping is generally accepted as the gold standard for very high load testing in excess of 3000 N, but is expensive, time-consuming, and requires significant ancillary equipment. Purely mechanical solutions such as metal jaw clamps, wire meshes, and others have been explored, but these techniques are either costly, have low load capacities, or have not proven to be reproducible. We have developed a novel tendon clamping technique that utilizes a slip-resistant polyester mesh sleeving that encases the tendon and is fixated at the bottom of the tendon/sleeve interaction with a giftbox suture. The loose end of the sleeving can then be tied in to the linear actuator or load cell apparatus using a timber hitch knot. The sleeving technique allows for loads of 2000-2500 N on the Achilles tendon, and is inexpensive, reproducible, and can be modified to apply loads to smaller tendons as well, though a length of tendon/sleeve overlap of at least 16 cm is required to reach maximum loads. This technique should assist researchers in integrating muscle forces into future biomechanical study designs.

Contact Angle Tuning of Copper Microporous Structures

Two-phase, capillary-fed cooling devices are appealing thermal management technologies due to their potential for high heat transfer performance and ease of system-level integration. While existing evaporative wicking structures such as copper inverse opals (CIOs) and copper wire meshes (CWMs) have shown promise for achieving target heat dissipation rates of 100 Wcm−2 or greater, the reliability of these structures for long-term device operation and optimal capillary-driven boiling performance has not received much attention. To ensure proper functionality of the evaporator wick, the microporous copper structures must retain a hydrophilic contact angle during device operation. Surface oxidation of the copper is a critical degradation mechanism that must be addressed to preserve the integrity of the wick. In this study, we systematically investigate the contact angle change of untreated copper and various copper oxides under different conditions. To avoid the formation of hydrophobic Cu2O, we pre-oxidize the copper micro porous wick to form hydrophilic cupric oxide CuO and study the effect of various thermal and chemical oxidation recipes on the hydrophilicity and morphology of the resulting structures. A chemical oxidation formula is implemented for the creation of a stable superhydrophilic surface at a low temperature (70°C) for copper inverse opals (CIOs) (5 μm pore size) and copper wire meshes (CWMs) (76 μm pore opening). The recipe has been optimized to create nano CuO needles with a length of < 100 nm and keep the necks (∼1 μm diameter) open for better capillary wicking of the working fluid. The findings of this study potentially benefit the development of copper-based capillary-fed cooling devices.

Experimental Performance of Flexural Behavior of Self Compacting ferrocement Flat and V Shaped Folded Roof Panels

The research paper present the experimental work carried out to investigate the behavior of different shaped ferrocement roof panels. The total twelve ferrocement self-compacting flat and V shaped folded roof panels with different number of wire meshes were casted and tested under two point loading. The number of wire meshes varied from 1 and 2 layers. Effect of these varying number of wire mesh layers on flexural strengths and deflection of Flat and V shaped folded roof panels are studied. And it is proved that the load carrying capacity of V shaped folded roof panel is found more with reduced deflection. Keywords: Flat panel, folded panel, mortar; wire mesh, self-compacting ferrocement.

Behavior of Self Compacted Concrete Ferrocement Beams

Many researchers have been conducted on the ferrocement as a low cost construction material and a flexible structural system. This experimental investigation on the behavior of ferrocement beams after exposed to different type of ferrocement and different of ferrocement layer are presented in this paper. The experimental program consisted of seven simply supported beams tested up to failure under four-point load. The dimensions of 150mm×250mm×2000mm. Each beam was reinforced using steel 2 f 12 in top and 2 f10 in bottom and the stirrups was 10 f 10/m. In addition to six of them contains ferrocement different steel wire meshes and different of ferrocement layer. The test specimens are divided in three groups and the results of each one compared with the control specimen. The first group (A) which used the welded wire mesh. The second group (B) which used the expanded wire mesh. But the third group (C) which reinforced using woven wire mesh. The mid span deflection, cracks, reinforcement and concrete strains of the tested beams were recorded and compared. The performance of the test beams in terms of ultimate flexure load cracking behavior and energy absorption were investigated. The experimental results emphasized that high ultimate loads, better crack resistance control, high ductility, and good energy absorption properties could be achieved by using the proposed ferrocement beams. The cracks propagation decreased and its number and width decreased by using woven, expanded and welded wire mesh especially in specimens with two layers of wire mesh. Theoretical calculation was carried out to compare the oplained results with the theoretical ones, which show good agreement.

INVESTIGATION ON LIGHT WEIGHT FERROCEMENT BEAMS UNDER MONOTONIC AND REPEATED LOADING

A Light weight ferrocement is a composite material consisting of cement-sand mortar (matrix) along with light weight ne aggregate ( In this research blast furnace slag is employed as light weight ne aggregate ) as a replacement of sand in some quantity and reinforced with layers of small diameter wire meshes . These studies mainly attempt to determine the rst crack strength, ultimate strength and the inuence of mesh wires on some of these properties. This work has been proposed to investigate on the Load-Deection and Moment-Curvature characteristics of lightweight ferrocement in monotonic and repeated loading. These results are expected to be useful in a better understanding of the exural behaviour of lightweight ferrocement and in the design of such members subjected to monotonic and repeated loading.

Surrounding Rock Stability Control Technology of Roadway in Large Inclination Seam with Weak Structural Plane in Roof

The surrounding rock control technology of mining roadways in large inclination seams with a weak structural plane in the roof is one of the most challenging fields in underground roadway support. In view of the serious deformation of the surrounding rock of the transportation roadway in the 1201 working face of a mine, the deformation and failure characteristics and instability mechanism of the surrounding rock of the roadway are analysed. The self-stability mechanical model of the roof block structure of the roadway with a large inclination under the support effect is established, and the support concept of “high pre-stressed asymmetric” and the combined support method of bolts, wire mesh, and cables are proposed. The rationality of the supporting scheme is verified by numerical simulation. The results show that: compared with bolt and wire mesh support, the maximum shear displacement of the roof’s weak layer under the combined support of bolt, wire meshes, and cable before and after mining is reduced by 86.78% and 83%, respectively, and the maximum total displacement of surrounding rock surface is reduced by 49.22% and 37.1%, respectively. The field monitoring results show that the combined support scheme can effectively control the deformation of the surrounding rock.

Permeability and the Ergun Equation as a Basis for Permeability Measurements of Metallic Foams and Wire Meshes

This paper concerns a method and a test set-up to measure the permeability of plates of metal foams and sets of wire meshes used to control flows in fluid filters and other flow systems designed to yield constant velocity distributions over large cross sections of flows. The method is based on permeability considerations using the Ergun equation to describe the pressure losses of packages of mono-dispersed spheres. One correlation is suggested for the permeability k over the entire range of mean velocities U0. A suitable measuring set-up was designed, built and used to measure the permeability of plates of metallic foams and sets of wire meshes. The specific objective of the present investigation was to provide permeability data for combined sets of wire meshes with flow properties that are mainly characterized by the wire meshes with the smallest mesh size. A method of data presentation is suggested that clearly illustrates the ranges of laminar and turbulent flows through the wire meshes. The results are compared with those for technical porous plates. The suggested presentation of the results indicates that the general features of the flows through porous plates of metal foams and wire meshes are the same.