58 research outputs found
Diffuse Reflectance Changes During the Culture of Cottage Cheese
A sensor for measuring diffuse reflectance of milk during the typical 6-h culture of cottage cheese was installed in a local manufacturing facility. Diffuse reflectance was found to increase slowly during the first three hours of the culture and increase rapidly toward the end of fermentation. The correlation between parameters generated from the diffuse reflectance profile and cutting time was sufficient to develop an algorithm for cutting time prediction. An algorithm incorporating tmax (time from adding culture to the maximum rate of change in reflectance) and slope of the reflectance curve at tmax predicted the operator selected cutting time with a standard error of 8.7 min
Elastic Properties and Internal Friction of Two Magnesium Alloys at Elevated Temperatures
The elastic properties and internal friction of two magnesium alloys were studied from 25 C to 450 C using Resonant Ultrasound Spectroscopy (RUS). The Young's moduli decrease with increasing temperature. At 200 C, a change in the temperature dependence of the elastic constants is observed. The internal friction increases significantly with increasing temperature above 200 C. The observed changes in the temperature dependence of the elastic constants and the internal friction are the result of anelastic relaxation by grain boundary sliding at elevated temperatures. Elastic properties govern the behavior of a materials subjected to stress over a region of strain where the material behaves elastically. The elastic properties, including the Young's modulus (E), shear modulus (G), bulk modulus (B), and Poisson's ratio (?), are of significant interest to many design and engineering applications. The choice of the most appropriate material for a particular application at elevated temperatures therefore requires knowledge of its elastic properties as a function of temperature. In addition, mechanical vibration can cause significant damage in the automotive, aerospace, and architectural industries and thus, the ability of a material to dissipate elastic strain energy in materials, known as damping or internal friction, is also important property. Internal friction can be the result of a wide range of physical mechanisms, and depends on the material, temperature, and frequency of the loading. When utilized effectively in engineering applications, the damping capacity of a material can remove undesirable noise and vibration as heat to the surroundings. The elastic properties of materials can be determined by static or dynamic methods. Resonant Ultrasound Spectroscopy (RUS), used in this study, is a unique and sophisticated non-destructive dynamic technique for determining the complete elastic tensor of a solid by measuring the resonant spectrum of mechanical resonance for a sample of known geometry, dimensions, and mass. In addition, RUS allows determination of internal friction, or damping, at different frequencies and temperatures. Polycrystalline pure magnesium (Mg) exhibits excellent high damping properties. However, the poor mechanical properties limit the applications of pure Mg. Although alloying can improve the mechanical properties of Mg, the damping properties are reduced with additions of alloying elements. Therefore, it becomes necessary to study and develop Mg-alloys with simultaneous high damping capacity and improved mechanical properties. Moreover, studies involving the high temperature dynamic elastic properties of Mg alloys are limited. In this study, the elastic properties and internal friction of two magnesium alloys were studied at elevated temperatures using RUS. The effect of alloy composition and grain size was investigated. The wrought magnesium alloys AZ31 and ZK60 were employed. Table 1 gives the nominal chemical compositions of these two alloys. The ZK60 alloy is a commercial extruded plate with a T5 temper, i.e. solution-treated at 535 C for two hours, quenched in hot water, and aged at 185 C for 24 hours. The AZ31 alloy is a commercial rolled plate with a H24 temper, i.e. strain hardened and partially annealed
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Impact of Separation on Refugee Families: Syrian Refugees in Jordan
The ongoing conflict in Syria, now entering its eighth year, has resulted in the largest refugee crisis since World War II. Nearly 6.5 million Syrians have become internally displaced, with an additional 5.6 million forced to leave their country to seek asylum. In the face of this displacement, greater attention is being given to complementary and alternative solutions such as reunification of separated family members. However, serious legal and procedural obstacles are obstructing the reunification of Syrian families across the Middle East and Europe. This study outlines several ways in which family separation negatively impacts Syrian refugees in Jordan. These effects are significant, and include financial burdens, increased child labour, emotional distress, broken social networks, parenting challenges and changes to familial roles
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“What’s happening in Syria even affects the rocks”: a qualitative study of the Syrian refugee experience accessing noncommunicable disease services in Jordan
Background
Humanitarian actors and host-countries in the Middle East and North Africa region are challenged with meeting the health needs of Syrian refugees and adjusting the response to contemporary humanitarian conditions – urban-based refugees, stressed host-country health systems and high NCD prevalence. Although several studies have explored NCD prevalence, utilization of services and barriers to access, these analyses took place prior to dramatic shifts in Jordanian health policy and did not account for nuances in health seeking and utilization behaviors or operational barriers. Accordingly, we aimed to understand the depth and nuances of Syrian refugees’ experiences accessing NCD services in urban and semi-urban settings in Jordan.
Methods
A qualitative study was conducted to explore the healthcare experiences of Syrian refugees in Jordan. The study team conducted 68 in-depth interviews with Syrian refugees in urban and semi-urban locations in central and northern Jordan.
Results
The findings indicated four themes key to understanding the healthcare experience: (1) emotional distress is a central concern and is frequently highlighted as the trigger for a non-communicable disease or its exacerbation; (2) service provision across all sectors – government, NGO, private – is complex, inadequate, expensive and fragmented, making engagement with the health sector physically and financially burdensome; (3) given financial constraints, participants make harmful decisions that further damage their health in order to reduce financial burdens, and (4) host-community members actively exhibit solidarity with their refugee neighbors and specifically do so during emergency health episodes. The findings from this study can be used to inform program design for forcibly displaced persons with NCDs and identify points of entry for effective interventions.
Conclusions
Opportunities exist for humanitarian and host-country actors to provide more comprehensive NCD services and to improve the relevance and the quality of care provided to Syrian refugees in Jordan. Global and national funding will need to align with front-line realities and foster better coordination of services between host-country health systems, private actors and non-governmental organizations
PCB-containing wood floor finish is a likely source of elevated PCBs in residents' blood, household air and dust: a case study of exposure
© 2008 Rudel et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
R-squared for general regression models in the presence of sampling weights
The coefficient of determination for general regression models is extended to incorporate sampling weights.
Preoperative factors associated with postoperative gait kinematics and kinetics after total hip arthroplasty.
OBJECTIVE:
To determine how patient factors: age, sex, body mass index (BMI), clinical scores and physical exam findings, are associated with gait recovery after total hip arthroplasty (THA).
METHOD:
145 subjects, who were evaluated with standard gait analysis, the Harris Hip Score (HHS), and a physical exam including passive range of motion (ROM), hip abductor strength assessment, before and after primary unilateral THA, were identified from an IRB-approved repository. Sagittal plane dynamic ROM and 3D peak external moments were averaged from operated-side normal-speed trials at each visit. We used linear regression analysis to evaluate the association among preoperative clinical factors and postoperative gait, with and without controlling for the influence of preoperative gait variables.
RESULTS:
Sagittal and transverse plane moments, and the peak abduction moment seen in early stance, significantly improved after THA (p < 0.001, effect size d = 0.22-1.04). The peak adduction moment did not change significantly (p = 0.646), although the change ranged from -2.7 to + 4.0 %Body weight Ă— height (-80% to +315%). Preoperative gait, clinical factors and patient characteristics predicted up to 33% of the variability in postoperative gait. Notably, greater preoperative abductor strength was associated with higher postoperative adduction and external rotation moments (R = 0.197-0.266, p < 0.05) after adjusting for age, sex, BMI and preoperative gait.
CONCLUSION:
Preoperative clinical factors predicted several specific aspects of objectively-characterized postoperative gait function. Physical exam findings can augment the predictive ability of clinical outcome measures, and potentially help guide rehabilitation plans
Ethnic differences in mortality from insulin-dependent diabetes mellitus among people less than 25 years of age.
Abstract is available from the publisher's website
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Elastic Properties and Internal Friction of Two Magnesium Alloys at Elevated Temperatures
The elastic properties and internal friction of two magnesium alloys were studied from 25 C to 450 C using Resonant Ultrasound Spectroscopy (RUS). The Young's moduli decrease with increasing temperature. At 200 C, a change in the temperature dependence of the elastic constants is observed. The internal friction increases significantly with increasing temperature above 200 C. The observed changes in the temperature dependence of the elastic constants and the internal friction are the result of anelastic relaxation by grain boundary sliding at elevated temperatures. Elastic properties govern the behavior of a materials subjected to stress over a region of strain where the material behaves elastically. The elastic properties, including the Young's modulus (E), shear modulus (G), bulk modulus (B), and Poisson's ratio (?), are of significant interest to many design and engineering applications. The choice of the most appropriate material for a particular application at elevated temperatures therefore requires knowledge of its elastic properties as a function of temperature. In addition, mechanical vibration can cause significant damage in the automotive, aerospace, and architectural industries and thus, the ability of a material to dissipate elastic strain energy in materials, known as damping or internal friction, is also important property. Internal friction can be the result of a wide range of physical mechanisms, and depends on the material, temperature, and frequency of the loading. When utilized effectively in engineering applications, the damping capacity of a material can remove undesirable noise and vibration as heat to the surroundings. The elastic properties of materials can be determined by static or dynamic methods. Resonant Ultrasound Spectroscopy (RUS), used in this study, is a unique and sophisticated non-destructive dynamic technique for determining the complete elastic tensor of a solid by measuring the resonant spectrum of mechanical resonance for a sample of known geometry, dimensions, and mass. In addition, RUS allows determination of internal friction, or damping, at different frequencies and temperatures. Polycrystalline pure magnesium (Mg) exhibits excellent high damping properties. However, the poor mechanical properties limit the applications of pure Mg. Although alloying can improve the mechanical properties of Mg, the damping properties are reduced with additions of alloying elements. Therefore, it becomes necessary to study and develop Mg-alloys with simultaneous high damping capacity and improved mechanical properties. Moreover, studies involving the high temperature dynamic elastic properties of Mg alloys are limited. In this study, the elastic properties and internal friction of two magnesium alloys were studied at elevated temperatures using RUS. The effect of alloy composition and grain size was investigated. The wrought magnesium alloys AZ31 and ZK60 were employed. Table 1 gives the nominal chemical compositions of these two alloys. The ZK60 alloy is a commercial extruded plate with a T5 temper, i.e. solution-treated at 535 C for two hours, quenched in hot water, and aged at 185 C for 24 hours. The AZ31 alloy is a commercial rolled plate with a H24 temper, i.e. strain hardened and partially annealed
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