Modeling Soil-Metal Sliding Resistance

2021 ◽  
Vol 64 (2) ◽  
pp. 435-446
Author(s):  
Donald H. Robbins ◽  
Clarence E. Johnson ◽  
Robert L. Schafer ◽  
Thomas R. Way
Keyword(s):  
Normal Stress ◽  
Path Length ◽  
Plastic Behavior ◽  
List Type ◽  
Soil Material ◽  
The Mean ◽  
Sliding Resistance ◽  
Mathematical Relationships ◽  
Resistance Data ◽  
Soil Metal

HighlightsA model was developed to express soil-metal sliding resistance in terms of normal stress and sliding path length.Soil-metal sliding resistance data, different from those used to develop the model, were acceptably simulated.The model is expected to be useful in the design and development of soil-engaging equipment.Abstract. Most previous soil-material sliding resistance studies have focused on the measurement and formulation of only qualitative relationships between sliding resistance and the material type, applied normal stress, sliding path length, and/or soil-properties. Few studies have attempted to formulate quantitative mathematical relationships between soil-material sliding resistance and these factors, or to mathematically express the relative contributions of the frictional and adhesive components to the total sliding resistance. In this study, a mathematical model was developed to express the components of soil-metal sliding resistance for a clay soil as functions of applied normal stress and sliding path length. The model is restricted to soil containing enough moisture to exhibit cohesive strength, but not so much moisture to exhibit gross plastic behavior. Soil-metal sliding resistance data, different from those used to develop the model, were acceptably simulated, as the mean square error between the simulated sliding resistance and the measured sliding resistance ranged from 0.653 to 2.44. Keywords: Adhesion, Friction, Normal stress, Sliding path length, Sliding resistance.

THE EXTRACTION OF PROLACTIN FROM HUMAN PITUITARY GLANDS

1965 ◽  
Vol 49 (1) ◽  
pp. 1-16 ◽  
Author(s):  
M. Apostolakis
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
List Type ◽  
Distilled Water ◽  
Hormone Activity ◽  
Isoelectric Precipitation ◽  
Human Pituitary ◽  
Pituitary Glands ◽  
Prolactin Content ◽  
The Mean

ABSTRACT A method for the extraction of prolactin from human pituitary glands is described. It is based on acetone drying, distilled water extraction, acetone and isoelectric precipitation. Two main products are obtained: Fraction R8 with a mean prolactin activity of 12.2 IU/mg and fraction U8 with a mean prolactin activity of 8.6 IU/mg. The former fraction does not contain any significant gonadotrophin activity and the latter contains on an average 50 HMG U/mg. In both cases contamination with ACTH and MSH is minimal. The growth hormone activity of both these fractions is low. It is postulated that in man too, prolactin and growth hormone are two distinct hormones. A total of 1250 human pituitary glands have been processed by this method. The mean prolactin content per pituitary gland has been found to be 73 IU.

IMMUNOREACTIVE GROWTH HORMONE IN PLASMA AND URINE IN JUVENILE DIABETICS BEFORE AND DURING INITIAL INSULIN TREATMENT

1974 ◽  
Vol 75 (1) ◽  
pp. 50-63 ◽  
Author(s):  
Kristian F. Hanssen
Keyword(s):  
Growth Hormone ◽  
Insulin Treatment ◽  
Juvenile Diabetes ◽  
Control Group ◽  
List Type ◽  
Newly Diagnosed ◽  
Renal Tubular Reabsorption ◽  
Juvenile Diabetics ◽  
The Mean ◽  
Renal Tubular

ABSTRACT Twenty newly diagnosed, but as yet untreated patients of both sexes with classical juvenile diabetes were investigated by determining the mean plasma immunoreactive growth hormone (IRHGH) and urinary IRHGH for a 24 hour period before and during initial insulin treatment. The plasma IRHGH was significantly higher (0.05 > P > 0.01) before than during initial insulin treatment. During initial insulin treatment, the mean plasma IRHGH was significantly higher (0.01 > P > 0.001) than in a control group. The urinary IRHGH was significantly higher (0.01 > P > 0.001) before than during insulin treatment. The increased urinary IRHGH observed before insulin treatment is thought to be partly due to a defective renal tubular reabsorption of growth hormone. No significant correlation was found between the mean blood sugar and plasma or urinary IRHGH either before or during insulin treatment.

CHROMATOGRAPHY OF THE 17-KETOGENIC STEROIDS IN THE DIAGNOSIS AND CONTROL OF CONGENITAL ADRENAL HYPERPLASIA

1960 ◽  
Vol XXXIII (II) ◽  
pp. 230-250 ◽  
Author(s):  
Eileen E. Hill
Keyword(s):  
Congenital Adrenal Hyperplasia ◽  
List Type ◽  
Adrenal Hyperplasia ◽  
Normal Children ◽  
Paediatric Practice ◽  
The Mean ◽  
Cortisone Therapy ◽  
And Control ◽  
Clinical Problems ◽  
Stimulation Of

ABSTRACT A method for the fractionation of the urinary 17-ketogenic steroids with no oxygen grouping at C11 and those oxygenated at C11, is applied to the clinical problems of congenital adrenal hyperplasia. In normal children the mean ratio of the non-oxygenated to oxygenated steroids is 0.24. In childrern with congenital adrenal hyperplasia the ratio is 2.3. The reason for this difference in ratio is discussed. The changes in ratio found under stimulation of the adrenal gland with exogenous or endogenous corticotrophin and the suppression with cortisone therapy are studied. This test can be applied to isolated samples of urine, a major advantage in paediatric practice, and can be carried out in routine laboratories. It is found to be reliable in the diagnosis and sensitive in the control of congenital adrenal hyperplasia.

Markov paths on the Poisson-Delaunay graph with applications to routeing in mobile networks

2000 ◽  
Vol 32 (01) ◽  
pp. 1-18 ◽  
Author(s):  
F. Baccelli ◽  
K. Tchoumatchenko ◽  
S. Zuyev
Keyword(s):  
Communication Networks ◽  
Mobile Networks ◽  
Path Length ◽  
Euclidean Distance ◽  
Voronoi Tessellation ◽  
Voronoi Cells ◽  
Ergodic Properties ◽  
Potential Applications ◽  
The Mean ◽  
Mobile Communication Networks

Consider the Delaunay graph and the Voronoi tessellation constructed with respect to a Poisson point process. The sequence of nuclei of the Voronoi cells that are crossed by a line defines a path on the Delaunay graph. We show that the evolution of this path is governed by a Markov chain. We study the ergodic properties of the chain and find its stationary distribution. As a corollary, we obtain the ratio of the mean path length to the Euclidean distance between the end points, and hence a bound for the mean asymptotic length of the shortest path. We apply these results to define a family of simple incremental algorithms for constructing short paths on the Delaunay graph and discuss potential applications to routeing in mobile communication networks.

Non-Traditional Applications of near Infrared Spectroscopy Based on the Optical Characteristic Models for a Biological Material Having Cellular Structure

1998 ◽  
Vol 6 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Satoru Tsuchikawa
Keyword(s):  
Biological Material ◽  
Path Length ◽  
Cellular Structure ◽  
Process Model ◽  
Near Infrared ◽  
Traditional Approach ◽  
Nir Spectroscopy ◽  
Optical Path Length ◽  
Optical Path ◽  
The Mean

Non-destructive measurements, based on near infrared (NIR) spectroscopy, on biological material with a cellular structure like wood require a non-traditional approach. We have developed new concepts to model the optical properties of a sample having cellular structure, for the illumination conditions of the spectrometer available to us. A set of optical models, which consisted of the directional characteristics models, the light-path models and the equivalent surface roughness model was proposed to clarify the behaviour of light propagation in a wood sample. Furthermore, the mean optical path length, which was derived by incorporating the nth power cosine model of radiant intensity into the diffusion process model in consideration of the parallel beam component of incident light, was calculated. By introducing the concept of equivalent sample thickness, compatible with the mean optical path length, into the Kubelka–Munk theory, generalised input/output equations for radiation were constructed. In this non-traditional application of NIR spectroscopy, these optical concepts make it possible to analyse both the physical condition and chemical composition of a biological material with a cellular structure.

Abstract 3016: Spirituality and Medication Adherence in Older African American Adults Diagnosed with Hypertension: A Qualitative Study

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Lisa M Lewis
Keyword(s):  
African American ◽  
Medication Adherence ◽  
Qualitative Study ◽  
Antihypertensive Medication ◽  
Demographic Data ◽  
Patient Treatment ◽  
List Type ◽  
Medication Regimen ◽  
Antihypertensive Medications ◽  
The Mean

Background : Medication adherence (ADH) is key to decreasing hypertension (HTN)-related morbidity and mortality in older African-American (AA) adults. However, older AA adults have poorer ADH to prescribed antihypertensive medications when compared to their younger and Caucasian-American counterparts. Patient beliefs and cultural concepts about their medications influence their medication ADH. An important cultural concept in this regards is spirituality, which is a significant resource in the AA community. Thus, the purpose of this qualitative study was to explore the role of spirituality in ADH to antihypertensive medications for older AA adults. Methods: Older AA adults who were members of a Program of All Inclusive Care for the Elderly (PACE) and who were (a) diagnosed with HTN; (b) prescribed at least one antihypertensive medication; (c) self-identified as African-American or Black; and (d) self-identified as spiritual completed one in-depth individual face-to-face in this qualitative descriptive study informed by grounded theory. Demographic data were also collected. Results : Twenty-one PACE members completed the study. All of the participants were female. The mean age of participants was 73 years with most completing high school (67%). The mean HTN diagnosis was16.7 years and mean number of prescriptions for antihypertensives was 3.3. Participants indicated that their spirituality was used in a collaborative process with formal health care to manage their ADH to antihypertensive medications. This process was identified as Partnering with God to Manage My Medications. Partnering with God to Manage My Medications indicated that the PACE members acknowledged personal responsibility for adhering to their antihypertensive medication regimen but used their spirituality as a resource for making decisions to remain adherent; coping with medication side effects; and increasing their self-efficacy to deal with barriers to ADH . Conclusions : Spirituality played a positive role in medication adherence for the PACE members. Incorporating individual beliefs, such as spirituality, into patient treatment for HTN may capitalize on their inner resources for medication ADH and demonstrates culturally appropriate care.

scholarly journals Functional Network Alterations as Markers for Predicting the Treatment Outcome of Cathodal Transcranial Direct Current Stimulation in Focal Epilepsy

2021 ◽  
Vol 15 ◽  
Author(s):  
Jiaxin Hao ◽  
Wenyi Luo ◽  
Yuhai Xie ◽  
Yu Feng ◽  
Wei Sun ◽  
...  
Keyword(s):  
Treatment Outcome ◽  
Prediction Model ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Path Length ◽  
Focal Epilepsy ◽  
Functional Network ◽  
Functional Networks ◽  
Direct Current Stimulation ◽  
The Mean

Background and PurposeTranscranial direct current stimulation (tDCS) is an emerging non-invasive neuromodulation technique for focal epilepsy. Because epilepsy is a disease affecting the brain network, our study was aimed to evaluate and predict the treatment outcome of cathodal tDCS (ctDCS) by analyzing the ctDCS-induced functional network alterations.MethodsEither the active 5-day, −1.0 mA, 20-min ctDCS or sham ctDCS targeting at the most active interictal epileptiform discharge regions was applied to 27 subjects suffering from focal epilepsy. The functional networks before and after ctDCS were compared employing graph theoretical analysis based on the functional magnetic resonance imaging (fMRI) data. A support vector machine (SVM) prediction model was built to predict the treatment outcome of ctDCS using the graph theoretical measures as markers.ResultsOur results revealed that the mean clustering coefficient and the global efficiency decreased significantly, as well as the characteristic path length and the mean shortest path length at the stimulation sites in the fMRI functional networks increased significantly after ctDCS only for the patients with response to the active ctDCS (at least 20% reduction rate of seizure frequency). Our prediction model achieved the mean prediction accuracy of 68.3% (mean sensitivity: 70.0%; mean specificity: 67.5%) after the nested cross validation. The mean area under the receiver operating curve was 0.75, which showed good prediction performance.ConclusionThe study demonstrated that the response to ctDCS was related to the topological alterations in the functional networks of epilepsy patients detected by fMRI. The graph theoretical measures were promising for clinical prediction of ctDCS treatment outcome.

Chemical Concentration and Spatial Uniformity of a Premixing In-Line Injection System Attached to a Variable-Rate Orchard Sprayer

2021 ◽  
Vol 64 (6) ◽  
pp. 1977-1987
Author(s):  
Zhihong Zhang ◽  
Heping Zhu ◽  
Zhiming Wei ◽  
Ramon Salcedo
Keyword(s):  
Spatial Distribution ◽  
Duty Cycle ◽  
Spray Deposition ◽  
Injection System ◽  
List Type ◽  
Variable Rate ◽  
Chemical Concentration ◽  
Fluorescent Tracer ◽  
Distribution Uniformity ◽  
The Mean

HighlightsA newly developed premixing in-line injection system attached to a variable-rate orchard sprayer was evaluated.Tests were conducted to verify the in-line injection system performance using a vertical spray patternator.Concentration accuracy and spatial distribution uniformity were determined with a fluorescent tracer.Uniform spray mixtures were obtained for different spray viscosities and duty cycle combinations.Abstract. Pesticide spray application efficiency is highly dependent on the chemical concentration accuracy and spatial distribution uniformity. In this study, the performance of a newly developed premixing in-line injection system was evaluated when it was attached to a laser-guided, pulse width modulated (PWM), variable-rate orchard sprayer. The chemical concentration accuracy was determined with respect to spray deposition with a fluorescent tracer, and the spatial distribution uniformity was determined with spray deposits at different heights on a vertical spray patternator. Outdoor tests were conducted with 27 combinations of target chemical concentration (1.0%, 1.5%, and 2.0%), viscosity of the simulated pesticide (1.0, 12.0, and 24.0 mPa·s), and various spray outputs manipulated with PWM duty cycles. For each injection loop, the amounts of the chemical concentrate and water discharged into the mixing line were measured separately in response to preset target concentrations. The results showed that the measured concentrations were consistent across the patternator heights, spray viscosities, and duty cycle combinations. For all treatments, the mean absolute percentage error (MAPE) of the measured concentration was 6.96%, indicating that the concentration accuracy of the system was acceptable. The mean coefficient of variation was 3.35%, indicating that the spatial distribution uniformity of the system was in the desirable range. In addition, there was little variation in chemical concentration for spray mixtures collected at different heights on the patternator. Thus, the premixing in-line injection system could adequately dispense chemical concentrate and water to produce accurate concentrations and uniform spray mixtures for variable-rate nozzles to discharge to targets. Keywords: Environment protection, Precision pesticide application, Laser-guided sprayer, Tank mixture disposal, Specialty crop.

Scaling of average receiving time on double-weighted polygon networks

2021 ◽  
Author(s):  
Xiaoyan Li ◽  
Yu Sun
Keyword(s):  
Iterative Method ◽  
Path Length ◽  
First Passage Time ◽  
Passage Time ◽  
Traffic Networks ◽  
Mean First Passage Time ◽  
First Passage ◽  
Specific Calculation ◽  
Calculation Process ◽  
The Mean

In this paper, we introduce a class of double-weighted polygon networks with two different meanings of weighted factors [Formula: see text] and [Formula: see text], which represent path-difficulty and path-length, respectively, based on actual traffic networks. Picking an arbitrary node from the hub nodes set as the trap node, and the double-weighted polygon networks are divided into [Formula: see text] blocks by combining with the iterative method. According to biased random walks, the calculation expression of average receiving time (ART) of any polygon networks is given by using the intermediate quantity the mean first-passage time (MFPT), which is applicable to any [Formula: see text] ([Formula: see text]) polygon networks. What is more, we display the specific calculation process and results of ART of the double-weighted quadrilateral networks, indicating that ART grows exponentially with respect to the networks order and the exponent is [Formula: see text] which grows with the product of [Formula: see text]. When [Formula: see text] increases, ART increases linearly ([Formula: see text]) or sublinearly ([Formula: see text]) with the size of networks, and the smaller value of [Formula: see text], the higher transportation efficiency.

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