LONG BEACH, CA, United States
LONG BEACH, CA, United States

Time filter

Source Type

Ahmadi L.,Logan Research | Merkley G.P.,Natural Resources Consulting Inc.
Irrigation Science | Year: 2017

This study analyzed the effects of population and urban growth on water demand for irrigation and other water users, as well as municipal wastewater quantity changes, by developing a new mathematical model. The model was developed to consider the potential for reuse of treated wastewater for agricultural irrigation, by analyzing the increasing quantity of wastewater production in an urban area. It was applied to a case study in Logan, Utah, whereby results from the model showed a total water demand of 0.7 and 1.27 m3/s in 2020 and 2050, respectively, while the model predicted that the average wastewater influent for Logan City would be more than double from 2010 to 2050. Accordingly, a model-predicted increase of 16% in the annual production of wastewater was observed from 2010 to 2025. The amount of wastewater production in 2030 was estimated to be 14.2 million m3/year, which is enough to produce food from irrigated agriculture for 11% of the future population of Logan City. This emphasizes the potential importance of reusing wastewater for irrigated agriculture. Water conservation was also studied and it showed that a 5% conservation of water volume could cover the needs of an additional 4.2 thousand people in 2030. © 2017 Springer-Verlag Berlin Heidelberg


Stillings L.L.,U.S. Geological Survey | Amacher M.C.,Logan Research
Chemical Geology | Year: 2010

Phosphorite from the Meade Peak Phosphatic Shale member of the Permian Phosphoria Formation has been mined in southeastern Idaho since 1906. Dumps of waste rock from mining operations contain high concentrations of Se which readily leach into nearby streams and wetlands. While the most common mineralogical residence of Se in the phosphatic shale is elemental Se, Se(0), Se is also an integral component of sulfide phases (pyrite, sphalerite and vaesite-pyrite ss) in the waste rock. It may also be present as adsorbed selenate and/or selenite, and FeSe 2 and organo-selenides.Se release from the waste rock has been observed in field and laboratory experiments. Release rates calculated from waste rock dump and column leachate solutions describe the net, overall Se release from all of the possible sources of Se listed above. In field studies, Se concentration in seepage water (pH 7.4-7.8) from the Wooley Valley Unit 4 dump ranges from 3600μg/L in May to 10μg/L by Sept. Surface water flow, Q, from the seep also declines over the summer, from 2L/s in May to 0.03L/s in Sept. Se flux ([Se]*Q) reaches a steady-state of <150mg/day in 1-4months, depending upon the volume of Q. Se release (mg/L) follows a first order reaction with a rate constant, k,=1.35-6.35e-3h -1 (11.8-55.6yr -1).Laboratory experiments were performed with the waste shale in packed bed reactors; residence time varied from 0.09 to 400h and outlet pH~7.5. Here, Se concentration increased with increasing residence time and release was modeled with a first order reaction with k=2.19e-3h -1 (19.2yr -1).Rate constants reported here fall within an order of magnitude of reported rate constants for oxidation of Se(0) formed by bacterial precipitation. This similarity among rate constants from both field and laboratory studies combined with the direct observation of Se(0) in waste shales of the Phosphoria Formation suggests that oxidation of Se(0) may control steady-state Se concentration in water draining the Wooley Valley waste dump. © 2009.


Regniere J.,Natural Resources Canada | Powell J.,Utah State University | Bentz B.,Logan Research | Nealis V.,Natural Resources Canada
Journal of Insect Physiology | Year: 2012

The developmental response of insects to temperature is important in understanding the ecology of insect life histories. Temperature-dependent phenology models permit examination of the impacts of temperature on the geographical distributions, population dynamics and management of insects. The measurement of insect developmental, survival and reproductive responses to temperature poses practical challenges because of their modality, variability among individuals and high mortality near the lower and upper threshold temperatures. We address this challenge with an integrated approach to the design of experiments and analysis of data based on maximum likelihood. This approach expands, simplifies and unifies the analysis of laboratory data parameterizing the thermal responses of insects in particular and poikilotherms in general. This approach allows the use of censored observations (records of surviving individuals that have not completed development after a certain time) and accommodates observations from temperature transfer treatments in which individuals pass only a portion of their development at an extreme (near-threshold) temperature and are then placed in optimal conditions to complete their development with a higher rate of survival. Results obtained from this approach are directly applicable to individual-based modeling of insect development, survival and reproduction with respect to temperature. This approach makes possible the development of process-based phenology models that are based on optimal use of available information, and will aid in the development of powerful tools for analyzing eruptive insect population behavior and response to changing climatic conditions. © 2012.


Wu H.H.,Logan Research | Gilchrist A.,Utah State University | Sealy K.D.,Utah State University | Bronson D.,Utah State University
IEEE Transactions on Industrial Informatics | Year: 2012

This paper presents the design of a 5 kW inductive charging system for electric vehicles (EVs). Over 90% efficiency is maintained from grid to battery across a wide range of coupling conditions at full load. Experimental measurements show that the magnetic field strength meets the stringent International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines for human safety. In addition, a new dual side control scheme is proposed to optimize system level efficiency. Experimental validation showed that a 7% efficiency increase and 25% loss reduction under light load conditions is achievable. The authors believe this paper is the first to show such high measured efficiencies for a level 2 inductive charging system. Performance of this order would indicate that inductive charging systems are reasonably energy efficient when compared to the efficiency of plug-in charging systems. © 2005-2012 IEEE.


Mohammed I.N.,University of Vermont | Tarboton D.G.,Logan Research
Water Resources Research | Year: 2012

The Great Salt Lake is a closed basin lake in which level and volume fluctuate due to differences between inflows and outflows. The only outflow is evaporation, which depends directly on lake area and salinity, both of which depend on lake volume. The lake's level, volume, and area adjust to balance, on average, precipitation and streamflow inflows by evaporation. In this paper, we examine the sensitivity of lake volume changes to precipitation, streamflow, and evaporation and the interactions among these processes and lake area and salinity related to volume. A mass balance model is developed to generate representative realizations of future lake level from climate and streamflow inputs simulated using the k-nearest-neighbor method. Climate and salinity are used to estimate evaporation from the lake using a Penman model adjusted for the salinity-dependent saturation vapor pressure. Our results show that fluctuation in streamflow is the dominant factor in lake level fluctuations, but fluctuations in lake area that modulate evaporation and precipitation directly on the lake are also important. The results also quantify the sensitivity of lake level to changes in streamflow and air temperature inputs. They predict that a 25% decrease in streamflow would reduce lake level by about 66 cm (2.2 feet), while a +4C air temperature increase would reduce lake level by about 34 cm (1.1 feet) on average. This sensitivity is important in evaluating the impacts of climate change or streamflow change due to increased consumptive water use on the level of the lake. © 2012 American Geophysical Union. All Rights Reserved.


Zhou A.L.,Logan Research | Hergert N.,Logan Research | Rompato G.,Utah State University | Lefevre M.,Utah State University
Journal of Nutrition | Year: 2015

Background: Whole grain consumption reduces the risk of major chronic diseases. It is not clear how whole grains exert their beneficial effects. Objective: The aim was to compare the physiologic effects of whole grain oat (WGO) flour with low bran oat (LBO) flour. Methods: Two AIN-93G-based diets were formulated with either WGO or LBO flour. Five-week-old male C57BL/6J mice were fed LBO (n = 11) and WGO (n = 13) diets for 8 wk. Cecal microbiota was profiled by pyrosequencing of the 16S ribosomal RNA gene. Data are reported as means 6 SEMs or antilogs of the mean (mean 2 SEM, mean + SEM). Results: The weight gain was 14.6%less in theWGO group during week 7 (P = 0.04).WGO improved insulin sensitivity as reflected by significantly lower plasma insulin [1500 (1370, 1650) ng/L vs. 2340 (2090, 2620) ng/L; P = 0.006], C-peptide (3980 6 548 ng/L vs. 7340 6 1050 ng/L; P = 0.007), and homeostasis model assessment-estimated insulin resistance (21.4 6 2.3 vs. 34.7 6 4.9; P = 0.03). Plasma total cholesterol was 9.9% less and non-HDL cholesterol was 11% less in the WGOgroup. A comparison of relative abundance indicated Prevotellaceae, Lactobacillaceae, and Alcaligenaceae familieswere 175.5% (P = 0.03), 184.5% (P = 0.01), and 150.0% (P = 0.004), respectively, greater in theWGO group and Clostridiaceae and Lachnospiraceae families were 527% (P = 0.004) and 62.6% (P = 0.01), respectively, greater in the LBO group. Cecal microbiota composition predicts 63.9% variation in plasma insulin and 88.9% variation in plasma non-HDL cholesterol. Conclusions: In mice, WGOs improved insulin sensitivity and plasma cholesterol profile compared with LBOs, and the effects were associated with the changes in cecal microbiota composition. Increasing WGO consumption may help improve insulin sensitivity and dyslipidemia in chronic diseases. © 2015 American Society for Nutrition.


Scali F.,American University of the Caribbean - School of Medicine | Pontell M.E.,St. George's University | Enix D.E.,Logan Research | Marshall E.,St. George's University
Spine Journal | Year: 2013

Background context: In recent literature, a soft-tissue communication between the rectus capitis posterior major (RCPma) muscle and the cervical dura mater has been identified. To the best of our knowledge, this communication has yet to be validated from a histological perspective nor has it been examined for neural tissue. Purpose: The purpose of this study was to examine the composition and true continuity of the communication between the RCPma and the dura mater at a microscopic level. The communication was also inspected for the presence of proprioceptive neurons. Study design: An anatomical and histological analysis of a novel structure in the atlantoaxial interspace. Methods: Gross dissection was performed on 11 cadavers to remove the RCPma, the soft-tissue communication, and a section of posterior cervical dura mater as one continuous unit. Paraffin embedding and sectioning followed by hematoxylin and eosin staining was conducted to validate the connection. Staining with antineurofilament protein fluorescent antibodies was performed to identify proprioceptive neural tissue on one specimen, and all findings were recorded via photographic documentation. Results: Histological investigation revealed a tendinous matrix inserting into both the RCPma and the posterior aspect of the cervical dura mater in all 11 specimens. In the one specimen examined for neural tissue, antineurofilament protein fluorescence revealed proprioceptive neurons within the communication. Immunoperoxidase staining demonstrated the insertion of these neurons into both the dura mater and the belly of the RCPma. Conclusions: The existence of a true connection between the RCPma and the cervical dura mater provides new insight in understanding the complex anatomy of the atlantoaxial interspace. The presence of a neural component within this connection suggests that it may serve another function aside from simply anchoring this muscle to the dura mater. Such a connection may be involved in monitoring dural tension and may also play a role in certain cervicogenic pathologies. This study also supports previous reports that no true membrane joins the posterior arch of the atlas to the laminae of the axis and contradicts the conventional belief that the ligamentum flavum joins these two structures. © 2013 Elsevier Inc. All rights reserved.


Nelson M.S.,Logan Research | Rittenour T.M.,Utah State University
Radiation Measurements | Year: 2015

Soil moisture is an important factor for dose-rate determination in luminescence and other dating methods as soil water content impacts sediment bulk density, alters rates of chemical reactions and attenuates effective exposure to nuclear radiation from the surrounding sediments and incoming cosmic rays. Given its importance in dose-rate calculation, methods for measuring and modeling soil water content are discussed, with special focus on semi-arid environments and other situations where modern in situ values are unlikely to be representative of mean soil moisture conditions. We present an alternative method for calculating sediment water content based on grain-size characteristics using the freely available Rosetta Lite v.1.1 software. Modeled outputs include saturation, residual and other water retention curve (WRC) parameters. WRCs were generated from model outputs using the van Genuchten (1980) equation, and mean annual water state was determined using soil moisture regime maps and classifications. Dose-rate values using modeled outputs and laboratory-measured in situ and saturation water content are compared in a test case using Holocene alluvial sediments from Kanab Creek in southern Utah, USA. Best practices for how to estimate mean annual water state for different soil moisture regimes and past soil moisture content in situations where in situ values are not representative of the burial history are discussed. © 2015 Elsevier Ltd.


Grant
Agency: Department of Health and Human Services | Branch: National Institutes of Health | Program: SBIR | Phase: Phase I | Award Amount: 248.50K | Year: 2016

The objective is to develop a wireless wearable device for non invasive assessment of continuous long term multi day beat by beat systolic and diastolic blood pressure BP in humans without use of cuff inflation or other arousing or activity interfering stimulation The proposed non invasive continuous BP CBP methodology addresses an unmet need for determination of extreme transient BP changes during obstructive sleep apnea following ictal periods with potential hypotension leading to sudden death in epilepsy momentary pressure changes in chronic hypertension and hypotensive patients and numerous other cardiovascular and respiratory conditions where BP changes accompany disease progression The device will be useful in patients who are likely to display sudden changes in blood pressure e g vascular surgery in whom close control of blood pressure is required e g head injured patients or in patients receiving drugs to maintain blood pressure Collectively the health care needs of over half of the US population at some point in their life could benefit from the device CBP monitoring provides numerous advantages The device is very low cost allowing ready replacement of ambulatory cuff based hr devices Instead of the intermittent spotty collection and arousal induction of automated BP cuff monitors the device offers continuous i e beat by beat data an obvious advantage in BP assessment during sleep or surgery The CBP technique allows accurate blood pressure readings at very low pressures for example during shock a critical aspect in emergency transport or care circumstances or in surgery The device is wireless avoiding multiple electrode placements requires only a single thoracic and wrist placed sensor and thus significantly improves patient comfort especially in long term blood pressure monitoring e g ICU or chronically ill home based patients moreover repeated cuff inflations are avoided The sensor design allows estimates of intravascular volume status from the wave shape of the arterial pressure data providing valuable insights into cardiovascular dynamics and BP measures which are impervious to distortions commonly induced by pulse transit time BP inference devices due to heart rate variations In this Phase I proposal we will continue to develop the prototype and provide initial validation in patients with intra arterial line BP data to CBP undergoing cardiovascular procedures and in a set of three levels of ambulatory hypertensive patients The initial clinical evidence will provide support for a later Phase II proposal in a full clinical trial Proposed project is non invasive device to assess long term multi day beat by beat systolic and diastolic blood pressure BP continuously in humans without use of cuff inflation The device is user friendly and optimized for long term monitoring applications


Grant
Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 229.02K | Year: 2014

DESCRIPTION (provided by applicant): The primary goal of long term monitoring is the Improvement of diagnostic yield. Despite the clear utility of Holter monitoring in clinical cardiology, issues of relatively low diagnostic yield, cost and inconvenience have motivated the development of ultra-portable devices referred to as ECG patch monitors. Although the gold standard for assessing cardiac rhythm abnormalities remains a 12-lead Holter, there is an increasing need to develop miniaturized portable monitoring devices for long term evaluation of cardiac rhythm in real-world environments such as the workplace or home. We have designed a novel ECG patch monitor called a Universal ECG Sensor (UES) for very long term monitoring of cardiac arrhythmic events. UESfeatures 12-lead recording capability and real-time telemetry. To facilitate patient acceptance, UES underwent a radical miniaturization and redesign to include wireless communication, water proofing and a patch carrier for attaching devices directly

Loading Logan Research collaborators
Loading Logan Research collaborators