scholarly journals A Novel System for Measuring Optical Properties in Arterial Blood of Man

2006 ◽  
Vol 3 (2) ◽  
pp. 87-92
Author(s):  
A. Castañeda-Miranda ◽  
L. D. L. Vizcaya
Keyword(s):  
Human Life ◽  
Light Attenuation ◽  
Acquisition Time ◽  
Fast Fourier Transformation ◽  
Electromagnetic Spectrum ◽  
Electromagnetic Excitation ◽  
Arterial Blood ◽  
Machine Communication ◽  
Day By Day

The necessity of man–machine communication has been increasing day by day because of the great number of approaches that help to make human life agile or comfortable. Health is one of the aspects that has generated more interest in recent years. The optical technologies are new technical tools that are being implemented for medical diagnosis and for describing various processes occurring within human blood. These techniques have the virtue of being nondestructive; in addition they have the advantage of remote direction by using anin situtechnique, with sensitivity capable of studying the properties of the blood through electromagnetic excitation. A device to obtain the electromagnetic spectrum in the blood has being designed and is presented in this work. This device uses a quartz lamp, emitting electromagnetic radiation between 200 nm and 2200 nm. A model for measuring the light attenuation through the blood is used. By applying a control in the frequency domain, a circuit device is designed. This device uses a database in time domain for its subsequent analysis by Fast Fourier Transformation in order to obtain absorption spectra. The acquisition time is of the order of microseconds, and the system is controlled automatically through accessible software from a personal computer.

IN SITU AND PILOT ORGAN PERFUSION TECHNIQUES FOR THE STUDY OF METABOLIC DYNAMICS

1972 ◽  
Vol 68 (2_Supplb) ◽  
pp. S9-S25 ◽  
Author(s):  
John Urquhart ◽  
Nancy Keller
Keyword(s):  
Cardiac Output ◽  
Large Fraction ◽  
Experimental Studies ◽  
Test Substance ◽  
Organ Perfusion ◽  
Systemic Blood ◽  
Experimental Control ◽  
Arterial Blood ◽  
Vascular Connections

ABSTRACT Two techniques for organ perfusion with blood are described which provide a basis for exploring metabolic or endocrine dynamics. The technique of in situ perfusion with autogenous arterial blood is suitable for glands or small organs which receive a small fraction of the animal's cardiac output; thus, test stimulatory or inhibitory substances can be added to the perfusing blood and undergo sufficient dilution in systemic blood after passage through the perfused organ so that recirculation does not compromise experimental control over test substance concentration in the perfusate. Experimental studies with the in situ perfused adrenal are described. The second technique, termed the pilot organ method, is suitable for organs which receive a large fraction of the cardiac output, such as the liver. Vascular connections are made between the circulation of an intact, anaesthetized large (> 30 kg) dog and the liver of a small (< 3 kg) dog. The small dog's liver (pilot liver) is excised and floated in a bath of canine ascites, and its venous effluent is continuously returned to the large dog. Test substances are infused into either the hepatic artery or portal vein of the pilot liver, but the small size of the pilot liver and its blood flow in relation to the large dog minimize recirculation effects. A number of functional parameters of the pilot liver are described.

scholarly journals High-Speed Video Analysis of the Process Stability in Plasma Spraying

2021 ◽  
Author(s):  
K. Bobzin ◽  
M. Öte ◽  
M. A. Knoch ◽  
I. Alkhasli ◽  
H. Heinemann
Keyword(s):  
Plasma Spraying ◽  
High Speed ◽  
Plasma Jet ◽  
Plasma Jets ◽  
Time Dependent ◽  
Acquisition Time ◽  
Fast Fourier Transformation ◽  
Frequency Spectra ◽  
Dependent Signal ◽  
The Stability

AbstractIn plasma spraying, instabilities and fluctuations of the plasma jet have a significant influence on the particle in-flight temperatures and velocities, thus affecting the coating properties. This work introduces a new method to analyze the stability of plasma jets using high-speed videography. An approach is presented, which digitally examines the images to determine the size of the plasma jet core. By correlating this jet size with the acquisition time, a time-dependent signal of the plasma jet size is generated. In order to evaluate the stability of the plasma jet, this signal is analyzed by calculating its coefficient of variation cv. The method is validated by measuring the known difference in stability between a single-cathode and a cascaded multi-cathode plasma generator. For this purpose, a design of experiment, covering a variety of parameters, is conducted. To identify the cause of the plasma jet fluctuations, the frequency spectra are obtained and subsequently interpreted by means of the fast Fourier transformation. To quantify the significance of the fluctuations on the particle in-flight properties, a new single numerical parameter is introduced. This parameter is based on the fraction of the time-dependent signal of the plasma jet in the relevant frequency range.

Engaging with the science and politics of biodiversity futures: a literature review

2021 ◽  
pp. 1-8
Author(s):  
Carina Wyborn ◽  
Elena Louder ◽  
Mike Harfoot ◽  
Samantha Hill
Keyword(s):  
Human Life ◽  
Global Environmental Change ◽  
Life Forms ◽  
Trade Offs ◽  
Global Environmental ◽  
Science And Politics ◽  
Science Community ◽  
Impact On Biodiversity ◽  
Made In

Summary Future global environmental change will have a significant impact on biodiversity through the intersecting forces of climate change, urbanization, human population growth, overexploitation, and pollution. This presents a fundamental challenge to conservation approaches, which seek to conserve past or current assemblages of species or ecosystems in situ. This review canvases diverse approaches to biodiversity futures, including social science scholarship on the Anthropocene and futures thinking alongside models and scenarios from the biophysical science community. It argues that charting biodiversity futures requires processes that must include broad sections of academia and the conservation community to ask what desirable futures look like, and for whom. These efforts confront political and philosophical questions about levels of acceptable loss, and how trade-offs can be made in ways that address the injustices in the distribution of costs and benefits across and within human and non-human life forms. As such, this review proposes that charting biodiversity futures is inherently normative and political. Drawing on diverse scholarship united under a banner of ‘futures thinking’ this review presents an array of methods, approaches and concepts that provide a foundation from which to consider research and decision-making that enables action in the context of contested and uncertain biodiversity futures.

In situ monitoring of electrosprayed water microdroplets using laser and LED light attenuation technique: Comparison with ultra-high-speed camera imaging

2021 ◽  
Vol 129 (18) ◽  
pp. 183305
Author(s):  
Mário Janda ◽  
Mostafa E. Hassan ◽  
Viktor Martišovitš ◽  
Karol Hensel ◽  
Michal Kwiatkowski ◽  
...  
Keyword(s):  
High Speed ◽  
Light Attenuation ◽  
In Situ Monitoring ◽  
High Speed Camera ◽  
Led Light ◽  
Camera Imaging ◽  
Ultra High Speed ◽  
Technique Comparison

Automatic Ignition Off For Bike When Brake Failure Using Limit Switch

2021 ◽  
Vol 23 (09) ◽  
pp. 994-1005
Author(s):  
S. Karthik ◽  
◽  
J.Silkson John ◽  
Keyword(s):  
General Public ◽  
Human Life ◽  
Dynamic State ◽  
Accident Rate ◽  
Human Errors ◽  
Safety Systems ◽  
Day By Day ◽  
Limit Switch

We cannot predict the Actual tendency of an accident at what time that is occurs so it is always preferred to be cautious while designing a system that is related to utility of general public . brakes failure is one of the most commonly seen automobile failure where a person or a family tend to loose not just a man or a person but also their livelihood .The accident rate in India has been increasing day by day and human errors tend to occur as the nature of doing a thing by a human includes errors .mostly todays technologies has emerged to be completely automated but still when it comes to vehicles the brakes tend to be applied normally by a human. Particularly in relation to human life and health Some special safety systems have been designed into cars for the security of the passengers only, while others have been built for the safety of others. This is a brake disaster warning route that continuously tracks the dynamic state of the brake. If the brake fails, the switch activates, and the ignition turns off automatically.

IN SITU MONITORING OF MEAN BLOOD OXYGEN SATURATION USING EXTENDED MODIFIED LAMBERT BEER MODEL

2015 ◽  
Vol 27 (01) ◽  
pp. 1550004 ◽  
Author(s):  
Audrey K. C. Huong ◽  
Xavier T. I. Ngu
Keyword(s):  
Oxygen Saturation ◽  
In Situ Monitoring ◽  
Blood Oxygen ◽  
Optical Monitoring ◽  
Hypertension Status ◽  
Blood Oxygen Saturation ◽  
Fitting Procedure ◽  
Arterial Blood ◽  
The Mean

We present the use of Extended Modified Lambert–Beer model for optical monitoring of mean blood oxygen saturation ( S m O 2) via a fitting procedure. This work focuses on the absorption characteristics of hemoglobin derivatives in the wavelength range of 520–600 nm to give the best estimates of S m O 2. The study of the feasibility of applying this analytic method to skin oximetry is via spectroscopy data collected from fingertips of four healthy volunteers both at rest and during arterial blood occlusion condition. The results revealed a decrease in the mean of mean and standard deviation of S m O 2 value of fingertips from 94.5 ± 2.19% when volunteers were at rest to 56.76 ± 5.8% during the arterial blood occlusion measurement. The larger variation in the value estimated for blood occlusion condition could be a result of differences in volunteers' physical fitness and hypertension status. These estimated S m O 2 values agreed reasonably well with the value reported in most of the previous studies. This work concluded that the proposed technique can potentially be used as a complementary technique to clinical assessment of skin grafts and burnt skin.

ANG II modifies cardiomyocyte function via extracardiac and intracardiac neurons: in situ and in vitro studies

1997 ◽  
Vol 272 (3) ◽  
pp. R766-R775 ◽  
Author(s):  
M. Horackova ◽  
J. A. Armour
Keyword(s):  
Guinea Pig ◽  
Receptor Antagonist ◽  
Neuronal Activity ◽  
Ang Ii ◽  
Arterial Blood ◽  
Cardiac Ganglia ◽  
In Situ Experiments ◽  
Anesthetized Dogs

To determine whether angiotensin II (ANG II) affects cardiac performance via neurons in intrathoracic cardiac ganglia, studies were performed on anesthetized dogs. To exclude possible vascular regulatory effects of ANG II, experiments were also performed using long-term cultures of adult guinea pig ventricular cardiomyocytes with or without intrathoracic neurons. 1) In in situ experiments in 10 anesthetized dogs, cardiac augmentation occurred when ANG II (10 microl or 0.1 ml; 10-100 microM) was administered into limited loci within acutely decentralized stellate or middle cervical ganglia that were neurally connected to, but not those disconnected from, the heart. In another 18 dogs, ANG II increased intrinsic cardiac neuronal activity when administered adjacent to such neurons or into their local arterial blood supply. Ventricular ionotropic effects elicited by ANG II were eliminated by timolol, whereas increases in intrinsic cardiac neuronal activity were not affected. Effects elicited by ANG II were eliminated by administration of a selective AT1 receptor antagonist (losartan) but not by a selective AT2 receptor antagonist (PD-123319). 2) In in vitro experiments, ANG II (100 nM) induced positive chronotropic effects on cultured adult guinea pig cardiomyocytes innervated with adult extrinsic or intrinsic cardiac neurons, but not those cultured without neurons. The frequency of calcium inward current (Ca(i)) transients (recorded by fura 2 fluorescence) increased in innervated cocultures but not in the noninnervated cardiomyocyte cultures; however, the amplitude of Ca(i) transients was not affected by ANG II in cultures or in freshly isolated adult guinea pig cardiomyocytes. ANG II-induced effects in cocultures were blocked by losartan but not PD-123319 or timolol. Thus 1) ANG II-sensitive neurons exist in intrathoracic extracardiac and intrinsic cardiac ganglia; 2) these neurons possess AT1 receptors; and 3) these neurons appear to act directly and indirectly via adrenergic neurons to enhance cardiomyocyte function.

scholarly journals Validation of MODIS snow cover images over Austria

2006 ◽  
Vol 3 (4) ◽  
pp. 1569-1601 ◽  
Author(s):  
J. Parajka ◽  
G. Blöschl
Keyword(s):  
Snow Cover ◽  
Classification Accuracy ◽  
Snow Depth ◽  
Seasonal Pattern ◽  
Acquisition Time ◽  
Spatial And Temporal Variability ◽  
Temporal Shift ◽  
Early Afternoon ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract. This study evaluates the Moderate Resolution Imaging Spectroradiometer (MODIS) snow cover product over the territory of Austria. The aims are (a) to analyse the spatial and temporal variability of the MODIS snow product classes, (b) to examine the accuracy of the MODIS snow product against in situ snow depth data, and (c) to identify the main factors that may influence the MODIS classification accuracy. We use daily MODIS grid maps (version 4) and daily snow depth measurements at 754 climate stations in the period from February 2000 to December 2005. The results indicate that, on average, clouds obscured 63% of Austria, which may significantly restrict the applicability of the MODIS snow cover images to hydrological modelling. On cloud-free days, however, the classification accuracy is very good with an average of 95%. There is no consistent relationship between the classification errors and dominant land cover type and local topographical variability but there are clear seasonal patterns to the errors. In December and January the errors are around 15% while in summer they are less than 1%. This seasonal pattern is related to the overall percentage of snow cover in Austria, although in spring, when there is a well developed snow pack, errors tend to be smaller than they are in early winter for the same overall percent snow cover. Overestimation and underestimation errors balance during most of the year which indicates little bias. In November and December, however, there appears to exist a tendency for overestimation. Part of the errors may be related to the temporal shift between the in situ snow depth measurements (07:00 a.m.) and the MODIS acquisition time (early afternoon).

scholarly journals Thermal Conductivity of Lightweight Concrete Block with Various Cooling Agent

2020 ◽  
Vol 12 (9) ◽  
Author(s):  
Masni A. Majid ◽  
◽  
Aina Syafawati Roslan ◽  
Noor Azlina Abdul Hamid ◽  
Norhafizah Salleh ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Energy Consumption ◽  
Energy Demand ◽  
Lightweight Concrete ◽  
Human Life ◽  
Concrete Block ◽  
Experimental Result ◽  
Cooling Agent ◽  
Reduce Energy Consumption ◽  
Day By Day

Energy was the important sources to human life. Due to increases energy demand in daily life, the energy consumption was increase day by day because of the heat load from solar radiation and heat produced by people. Toward sustainable development, this research was carried out to develop a lightweight concrete (LWC) block with various cooling agent such as glycerine, propylene glycol, coconut shell and gypsum powder. Six lightweight concrete (LWC) block with the size 250mm (L) × 250mm (W) × 100mm (T) were tested for thermal conductivity value. From the experimental result, it shows that lightweight concrete (LCW) block with various cooling agent obtained thermal conductivity value of 0.17W/mK - 0.36W/mK lower than thermal conductivity value for normal lightweight concrete (0.8W/mK) depending on concrete density. The lightweight concrete (LCW) block with cooling agent having low thermal conductivity value will reduce energy consumption in building.

Sensitivity of canine intrinsic cardiac neurons to H2O2and hydroxyl radical

1998 ◽  
Vol 275 (4) ◽  
pp. H1434-H1440 ◽  
Author(s):  
Gregory W. Thompson ◽  
Magda Horackova ◽  
J. Andrew Armour
Keyword(s):  
Free Radicals ◽  
Blood Supply ◽  
Neuronal Activity ◽  
Chelating Agent ◽  
Right Atrial ◽  
Arterial Blood Supply ◽  
Arterial Blood ◽  
Oxygen Derived Free Radicals ◽  
Oxidative Challenge

To determine whether intrinsic cardiac neurons are sensitive to oxygen-derived free radicals in situ, studies were performed in 44 open-chest anesthetized dogs. 1) When H2O2(600 μM) was administered to right atrial neurons of 36 dogs via their local arterial blood supply, neuronal activity either increased (+92% in 16 dogs) or decreased (−61% in 20 dogs), depending on the population of neurons studied. H2O2(600 μM) administered into the systemic circulation did not affect neuronal activity, measured cardiac indexes, or aortic pressure. 2) The iron-chelating agent deferoxamine (20 mg/kg iv), a chemical that prevents the formation of oxygen-derived free radicals, reduced the activity generated by neurons (−57%) in 8 of 10 dogs. 3) H2O2did not affect neuronal activity when administered in the presence of deferoxamine in these 10 dogs. 4) When the ATP-sensitive potassium (KATP) channel opener cromakalim (20 μM) was administered to intrinsic cardiac neurons in another 21 animals via their regional arterial blood supply, ongoing neuronal activity in 15 of these dogs decreased by 54%. 5) Neuronal activity was not affected by H2O2when administered in the presence of cromakalim in 16 dogs. These data indicate that 1) some intrinsic cardiac neurons are sensitive to exogenous H2O2, 2) such neurons are tonically influenced by locally produced oxygen-derived free radicals in situ, and 3) intrinsic cardiac neurons possess KATPchannels that are functionally important during oxidative challenge.

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