In vitro comparison of cortical bone temperature generation between traditional sequential drilling and a newly designed step drill in the equine third metacarpal bone

Summary Objectives: To compare heat generation and time to finish between a new step drill and sequential drilling in order to create a 6.2 mm pilot hole for insertion of a positive profile transfixation pin into the equine third metacarpal bone. Methods: Nine pairs of equine third metacarpal bones from cadavers of adult horses were used. Maximum temperature rise of the bone was measured continuously at the cis- and trans-cortices 1, 2 and 3 mm from the final pilot hole during creation of a 6.2 mm hole using a step drill and sequential drilling with 4.5, 5.5 and 6.2 mm drill bits. Five holes were drilled into the mid diaphysis of each bone in lateral to medial direction, and drilling forces of 60, 80 and 120 N were used (15 holes in each group). Time from start to finish was measured and cortical thickness was recorded for each hole. Results: The maximum heat generation (mean [95% CI]) with step drilling and sequential drilling was not significantly different at 60 N and 120 N of drilling force. However, at 80 N of drilling force, the 2.13 ºC difference between the two drilling techniques was significant. The time to finish (seconds) was significantly shorter for the holes created by step drilling (35.1 [32.06 – 37.59]) than by sequential drilling (145.8 [138.52 – 151.67]) (P < 0.001). Clinical Relevance: Based on our results, we concluded that the step drill is a viable alternative to traditional sequential drilling of equine third metacarpal bone because it did not result in excessive heat generation that can result in bone necrosis.

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The Assessment of the Maximum Heat Production and Cooling Effectiveness of Three Different Drill Types (Conical vs. Cylindrical vs. Horizontal) during Implant Bed Preparation—An In Vitro Study

Applied Sciences ◽

10.3390/app11219961 ◽

2021 ◽

Vol 11 (21) ◽

pp. 9961

Author(s):

Stefan Ihde ◽

Bartosz Dalewski ◽

Łukasz Pałka

Keyword(s):

In Vitro Study ◽

Maximum Temperature ◽

Internal Cooling ◽

Type I ◽

Ir Camera ◽

Maximum Heat ◽

Disc Cutters ◽

Cooling Hole ◽

Implant Bed

The aim of this experimental study was to verify thermal diffusion differences, by measuring the maximum temperature achieved with different drill shapes. Synthetic bone blocks of type I density made from solid rigid polyurethane (PUR) foam were used to perform the drilling procedures. The experiment was conducted at three different rotation speeds: 800, 3000 and 5000 rpm. Conical drills (with and without an internal cooling hole) were compared with horizontal drills and disc drills. The temperature during drilling for implant bed preparation was estimated with the use of thermocouples and an infrared (IR) camera. The temperature during drilling with disc cutters for lateral basal implants did not exceed 33 ∘C and the temperature decreased in proportion to higher drill speed. The results indicate that the tested design is safe and will not cause bone overheating.

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A Development of Air Controlled Oxidizer for Treatment of Depleted Uranium Chip Waste

MRS Proceedings ◽

10.1557/proc-506-979 ◽

1997 ◽

Vol 506 ◽

Cited By ~ 1

Author(s):

Kweon Ho Kang ◽

Kil Jeong Kim ◽

Hyun Kyoo Shin ◽

Chul Kim ◽

Young Moo Park

Keyword(s):

Fly Ash ◽

Heat Generation ◽

Flow Rate ◽

Uranium Oxide ◽

Oxidation Temperature ◽

Maximum Temperature ◽

Complete Oxidation ◽

Heating Rates ◽

Maximum Heat ◽

Image Position

ABSTRACTIn Korea Depleted Uranium(DU) is used in manufacturing a metallic nuclear fuel for the Korean Multi-Purpose Research Reactor(KMRR). In the manufacturing processes it produces DU chips and scraps as a waste material which composed of U-Ti, U-Zr, U-Mo and U-Si intermetallic compound. In this study Air Controlled Oxidizer(ACO) has been developed which facilitates DU to be converted into U308, the most stable form of uranium. Since DU chips oxidize rapidly and their heat of oxidation is very high(4.199kJ/g, U3O8), the inside temperature of the oxidizer is likely going up rapidly. Therefore the oxidizer must be able to be cooled properly or temperature increasement of the oxidizer must be under control. Kang et al.[1] reported for the oxidation of U-0.75wt%/o Ti chips in air that U308 was detected at the temperature above 350°C. And they[2] also reported that the maximum heat generation per unit time during oxidation was as follows:where Q was the maximum heat generation per unit timeWDU was the weight of DU loaded in ACOdw/dt was the reaction rateVair was the flow rate of input airR was the universal gas constantand T was the absolute temperature.From eq.(1) the maximum heat generation per unit time during oxidation is only function of the weight of DU loaded in ACO and the oxidation rate which is dependent on the oxidation temperature or the flow rate of input air.The ACO consists of an air flow meter, an air heater, an oxidation chamber with inner heater(capacity 7.5kW), an ash collection tank, a fly ash collector, a pressure gauge, a safety valve, and a soaking tank. The air flow meter is used to control the flow rate of input air below theoretical air requirement limit for the complete oxidation of DU. The inner heater is used to heat the inside of the oxidizer to an optimum oxidation temperature. The ash collection tank is used to collect uranium oxide powder after completion of oxidation. The fly ash collector is used both to collect flying ashes and to condense vaporized uranium oxide. Also, in ACO, DU chips are not ignited directly in order to prevent rapid temperature increasement. The oxidation environment only is achieved by heating the inside of oxidizer.To find effect of the oxidation temperature on the temperature of the oxidation chamber during treatment of DU, we conduct the experiment by changing heating rates of inner heater, 3, 4, 5 and 6kW, respectively. We conduct experiments for 120 minute with 2/min input air. However, it turned out that the complete oxidation is reached within 60 minute. After complete oxidation the weight gains of the DU chips is from 4.5 to 5.0 wt0/o and the DU chips are pulverized and they are converted to U 08 and 979 Mat. Res. Soc. Symp. Proc. Vol. 506 1998 Materials Research Society During the oxidation, maximum temperature increases to 470, 497.5, 572.5 and 6771C for heating rates 3, 4, 5 and 6kW, respectively. As the temperatures of the oxidation chamber outside surface are not exceed 1501C, however, DU chips are treated safely. In each experiment, weight before and after oxidation, the oxide forms of the product and the maximum temperature in the oxidation chamber during oxidation are shown in table 1. The maximum temperature profiles of the chamber inside and surface for time and heating rates are shown in Fig. I and 2, respectively.

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Ultrasonic-Assisted Drilling of Cortical and Cancellous Bone in a Comparative Point of View

10.21203/rs.3.rs-368773/v1 ◽

2021 ◽

Author(s):

Sousan Pourgiv ◽

Nima Jamshidi ◽

Aminollah Mohammadi ◽

Alireza Mosavar

Keyword(s):

Bone Tissue ◽

Cancellous Bone ◽

Healing Process ◽

Drilling Process ◽

Drilling Force ◽

Excessive Heat ◽

Micro Cracks ◽

Ultrasonic Assisted ◽

Conventional Drilling

Abstract Background: A potential method in drilling of bone is ultrasonic-assisted drilling. In addition, during the drilling of bone, which is common in clinical surgeries, excessive heat generation and drilling force may lead to damages in bone tissue, and thus to failure of implants and fixation screws or delay in healing process. The aim of this study was to appraise efficiency of ultrasonic-assisted drilling in comparison to conventional drilling.Methods: In addition to investigating drilling force and temperature elevation, their effects on arising osteonecrosis and micro-cracks were explored in ultrasonic-assisted and conventional drilling through histopathologic assessment and microscopic imaging. In this regard, three drilling speeds and two drilling feed-rates were considered as drilling variables in the in-vitro experiments. Moreover, numerical modeling gave an insight into temperature distribution during drilling process in the both methods and compared three different vibration amplitudes. Results: Although temperature elevations were lower in the conventional drilling, the ultrasonic-assisted drilling had lesser drilling forces. Furthermore, the latter method had smaller osteonecrosis regions, and did not have micro-cracks in cortical bone and destructions in structure of cancellous bone.Conclusions: The ultrasonic-assisted drilling, which caused lesser damages to the bone tissue in both cortical and cancellous bone, was more comparatively advantageous.

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Pullout Strength of Screws in Foal Third Metacarpal Bone after Overdrilling a 4.5 mm Hole

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.1055/s-0038-1632548 ◽

1998 ◽

Vol 11 (04) ◽

pp. 200-204 ◽

Cited By ~ 1

Author(s):

K. Kelly ◽

G. S. Martin ◽

D. J. Burba ◽

S. A. Sedrish ◽

R. M. Moore

Keyword(s):

Cortical Bone ◽

Metacarpal Bone ◽

Pullout Strength ◽

Cancellous Screw ◽

Bone Screw ◽

Screw Insertion ◽

Holding Power ◽

Cortical Screw ◽

Metaphyseal Bone

SummaryThe purpose of the study was to determine and to compare the in vitro pullout strength of 5.5 mm cortical versus 6.5 mm cancellous bone screws inserted in the diaphysis and metaphysis of foal third metacarpal (MCIII) bones in threaded 4.5 mm cortical bone screw insertion holes that were then overdrilled with a 4.5 mm drill bit. This information is relevant to the selection of a replacement screw if a 4.5 mm cortical screw is stripped during orthopaedic surgery. In vitro pullout tests were performed in two independent cadaver studies, each consisting of 12 foal MCIII bones. Two 4.5 mm cortical screws were placed either in the mid-diaphysis (study 1) or distal metaphysis (study 2) of MCIII bones. The holes were then overdrilled with a 4.5 mm bit and had either a 5.5 mm cortical or a 6.5 mm cancellous screw inserted; screw pullout tests were performed at a rate of 0.04 mm/s until screw or bone failure occurred.The bone failed in all of the tests in the diaphyseal and metaphyseal bone. The holding power for 6.5 mm cancellous screws was significantly (p <0.05) greater than for 5.5 mm cortical screws in both the diaphysis and metaphysis. There was not any difference in the holding power of screws in either the diaphysis or the metaphysis between proximal and distal screw holes.If a 4.5 mm cortical bone screw strips in MCIII diaphyseal or metaphyseal bone of foals, a 6.5 mm cancellous screw would provide greater holding power than a 5.5 mm cortical screw.In order to provide information regarding selection of a replacement screw if a 4.5 mm cortical screw is stripped, the in vitro pullout strength was determined for 5.5 mm cortical and 6.5 mm cancellous screws inserted in third metacarpal diaphyseal and metaphyseal bone of foals in which threaded 4.5 mm cortical bone screw insertion holes had been overdrilled with a 4.5 mm bit. The holding power of the 6.5 mm cancellous screw was significantly greater than the 5.5 mm cortical screw in both the diaphysis and metaphysis of foal third metacarpal bone. Thus, it appears that if a 4.5 mm cortical screw is stripped during orthopaedic surgery in foals, a 6.5 mm cancellous screw would provide superior holding power.

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Effect of Guiding Sleeve Design on Intraosseous Heat Generation During Implant Site Preparation (In Vitro Study)

Journal of Prosthodontics ◽

10.1111/jopr.13370 ◽

2021 ◽

Author(s):

Amal Ashry ◽

Mohamed Sherine El Attar ◽

Osama Ahmed Elsamni ◽

Ingy Saied Soliman

Keyword(s):

Heat Generation ◽

In Vitro Study ◽

Site Preparation ◽

Vitro Study ◽

Implant Site Preparation

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On the in Vitro Hyperthermia of Magnetic Fluid in AC Magnetic Field

ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer, Volume 3 ◽

10.1115/mnhmt2009-18547 ◽

2009 ◽

Author(s):

Junfeng Jiang ◽

Ruoyu Hong ◽

Xiaohui Zhang ◽

Hongzhong Li

Keyword(s):

Magnetic Field ◽

Magnetic Fluid ◽

Volume Fraction ◽

Maximum Temperature ◽

Magnetic Fluid Hyperthermia ◽

Ac Magnetic Field ◽

Hyperthermia Therapy ◽

Good Biocompatibility ◽

High Chemical Stability

Hyperthermia therapy for cancer has attracted much attention nowadays. The study on the heat transfer in the magnetic fluid and the tumor is crucial for the successful application of magnetic fluid hyperthermia (MFH). Water-based Fe3O4 magnetic fluid is expected to be a most appropriate candidate for MFH due to the good biocompatibility, high saturation magnetization, super-paramagnetization and high chemical stability. In this paper, we explore the heat generation and transfer in magnetic fluid which is placed under an AC magnetic field. It is found that the amplitude and the frequency of alternating magnetic field, particle size and volume fraction have a pronounce influence on maximum temperature of hyperthermia.

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Resistance of Corynebacterium pseudotuberculosis in the Brazilian semiarid environment

Pesquisa Veterinária Brasileira ◽

10.1590/1678-5150-pvb-4960 ◽

2018 ◽

Vol 38 (6) ◽

pp. 1091-1096 ◽

Cited By ~ 2

Author(s):

Maria C.A. Sá ◽

Samily A.S. Oliveira ◽

Edmilson M. Dantas Jr ◽

Gisele V. Gouveia ◽

João J.S. Gouveia ◽

...

Keyword(s):

Survival Rates ◽

Control Measures ◽

Corynebacterium Pseudotuberculosis ◽

Maximum Temperature ◽

Caseous Lymphadenitis ◽

Biofilm Production ◽

Brazilian Semiarid ◽

Higher Temperature ◽

Inoculum Survival

ABSTRACT: The semiarid northeast of Brazil contains a unique biome known as caatinga, with a maximum temperature of 40 ºC and a relativity humidity of 56%. The caatinga is characterized by a variety of plants, including Cereus jamacaru Dc (mandacaru), Poincianella microphylla Mart. ex G. Don (catingueira), Pilosocereus gounellei FAC Weber (xique-xique) and Mimosa tenuiflora (Willd.) Poir (jurema preta). Sheep and goat industries are economically strong in that region, despite the fact that caseous lymphadenitis is highly prevalent. The aim of the present study was to assess the survival and biofilm production of Corynebacterium pseudotuberculosis isolates in the environment and under controlled temperatures (28°C, 37°C and 42°C) under different surfaces (plants, soil, wood, wire and thorns). In addition, we investigated the effects of applying the disinfectants chlorhexidine, hypochlorite and quaternary ammonia in soil, tiles, wood and vegetation cover. Four strains of C. pseudotuberculosis were selected (two from goats and two from sheep) for inoculation according to their in vitro biofilm production. Adherence to microplates was used to assess the biofilm-forming ability of the bacteria. Lower survival rates were observed when isolates of C. pseudotuberculosis were subjected to a temperature of 42°C. In terms of caatinga biome plants, contamination of jurema-preta plants resulted in the lowest survival rates. The disinfectant quaternary ammonia promoted a lower inoculum survival in all surfaces. The disinfectants and the higher temperature contributed to the reduction of biofilm production in isolates of C. pseudotuberculosis. knowledge of these patterns is important for the establishment of disease control measures, given the questionable efficacy of the treatment and the immuno-prophylaxis of caseous lymphadenitis.

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Effects of rainfall and temperature on the feeding value of barley straw in a semi-arid Mediterranean environment

The Journal of Agricultural Science ◽

10.1017/s002185969700470x ◽

1997 ◽

Vol 129 (3) ◽

pp. 353-366 ◽

Cited By ~ 8

Author(s):

A. V. GOODCHILD

Keyword(s):

Mediterranean Region ◽

Meteorological Data ◽

Small Ruminants ◽

Barley Straw ◽

Maximum Temperature ◽

Mean Annual Precipitation ◽

Monthly Precipitation ◽

Feeding Value ◽

The Mediterranean

Annual variation in the feeding value of barley straw (Hordeum vulgare L. subsp. vulgare) is economically significant in the Mediterranean region. The relationship between the feeding value for sheep of several winter-planted barley cultivars and monthly meteorological data was analysed at Tel Hadya, northwest Syria (mean annual precipitation 330 mm) in 11 years. Indicators of feeding value included contents of neutral detergent fibre, acid detergent fibre and nitrogen (11 years), voluntary straw intake by sheep (10 years), voluntary digestible organic matter intake (9 years), in sacco dry matter loss and lignin content (8 years), in vitro digestibility (7 years) and in vitro gas production (6 years). Monthly meteorological data included total precipitation, mean minimum and mean maximum air temperatures.Conditions likely to decrease grain yield tended to increase the feeding value of straw. Low mean minimum temperature in February, low precipitation in January, February, March and April, and high mean maximum temperature in March, April and May increased one or more indicators of straw feeding value (by both bivariate and multiple regression, P<0·05). Precipitation before January affected grain and straw yield but had little effect on the feeding value of straw.Genotype × year interactions had a meteorological component; the superior feeding value of the straw of locally-adapted cultivars v. exotic cultivars was only seen in years with cool or wet springs. This has implications for the genetic selection of crops with better straw feeding value.Models based on monthly precipitation and temperature, calibrated for locations in the Mediterranean region, can predict the nutritive value of straw and aid the planning of rations for small ruminants.

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Musculoskeletal models of a human and bonobo finger: parameter identification and comparison to in vitro experiments

PeerJ ◽

10.7717/peerj.7470 ◽

2019 ◽

Vol 7 ◽

pp. e7470 ◽

Cited By ~ 2

Author(s):

Alexander Synek ◽

Szu-Ching Lu ◽

Evie E. Vereecke ◽

Sandra Nauwelaerts ◽

Tracy L. Kivell ◽

...

Keyword(s):

Parameter Identification ◽

Metacarpal Bone ◽

Combined Loading ◽

Model Parameters ◽

Musculoskeletal Models ◽

Bone Loading ◽

Finger Model ◽

Fingertip Forces ◽

Human Primate

Introduction Knowledge of internal finger loading during human and non-human primate activities such as tool use or knuckle-walking has become increasingly important to reconstruct the behaviour of fossil hominins based on bone morphology. Musculoskeletal models have proven useful for predicting these internal loads during human activities, but load predictions for non-human primate activities are missing due to a lack of suitable finger models. The main goal of this study was to implement both a human and a representative non-human primate finger model to facilitate comparative studies on metacarpal bone loading. To ensure that the model predictions are sufficiently accurate, the specific goals were: (1) to identify species-specific model parameters based on in vitro measured fingertip forces resulting from single tendon loading and (2) to evaluate the model accuracy of predicted fingertip forces and net metacarpal bone loading in a different loading scenario. Materials & Methods Three human and one bonobo (Pan paniscus) fingers were tested in vitro using a previously developed experimental setup. The cadaveric fingers were positioned in four static postures and load was applied by attaching weights to the tendons of the finger muscles. For parameter identification, fingertip forces were measured by loading each tendon individually in each posture. For the evaluation of model accuracy, the extrinsic flexor muscles were loaded simultaneously and both the fingertip force and net metacarpal bone force were measured. The finger models were implemented using custom Python scripts. Initial parameters were taken from literature for the human model and own dissection data for the bonobo model. Optimized model parameters were identified by minimizing the error between predicted and experimentally measured fingertip forces. Fingertip forces and net metacarpal bone loading in the combined loading scenario were predicted using the optimized models and the remaining error with respect to the experimental data was evaluated. Results The parameter identification procedure led to minor model adjustments but considerably reduced the error in the predicted fingertip forces (root mean square error reduced from 0.53/0.69 N to 0.11/0.20 N for the human/bonobo model). Both models remained physiologically plausible after the parameter identification. In the combined loading scenario, fingertip and net metacarpal forces were predicted with average directional errors below 6° and magnitude errors below 12%. Conclusions This study presents the first attempt to implement both a human and non-human primate finger model for comparative palaeoanthropological studies. The good agreement between predicted and experimental forces involving the action of extrinsic flexors—which are most relevant for forceful grasping—shows that the models are likely sufficiently accurate for comparisons of internal loads occurring during human and non-human primate manual activities.

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