Mississippi State University
  • Starkville, Mississippi, United States
Recent publications
In recent years, emerging sensing and detection technologies have been adopted to enhance safety in many construction sites. In this paper, we proposed to use a radio frequency identification (RFID) system, which consists of RFID readers, semi-passive tags and an Internet of Things (IoT) network, to prevent accidents on construction sites. The proposed system with multiple functions is versatile for different situations. Firstly, it can effectively detect the entry/exit activities when workers carrying tags access a site. Such a record is essential in daily project management. Secondly, the system can be programmed to flexibly create various virtual zones of different sizes and shapes. The virtual zones are usually hazardous ones that anyone cannot approach and enter. The semi-passive tag will warn an intruder if someone intentionally or accidentally intrudes the zones. A warning message is generated and sent to the remote server in real-time via the IoT network. Lastly, by adopting the advanced LoRa technology in the IoT network, the sensed data can be wirelessly transmitted over a longer distance than other wireless technologies, such as WiFi and Bluetooth, thereby reducing the number of transmission hops and improving the transmission efficiency.
Swirling flows have applications in several areas which includes enhanced heat transfer and combustion. In these applications, swirling jets typically impinge on a target surface either orthogonally or at an angle. This paper presents an experimental and numerical investigation on the effects of jet-to-target spacing (z/d – 0.5 to 4) on heat transfer characteristics of orthogonally impinging swirling jets in comparison to geometrically similar cylindrical jet. Further, obliquely impinging jets (at z/d = 4) with anti-clockwise swirl (when viewing target surface from the jet) have been studied. Transient liquid crystal thermography experiments were carried out for above configurations at jet Reynolds number of 18,000 for orthogonal impingement and for Re ranging from 9000 to 18,000 for obliquely impinging swirling jet. The experimentally obtained local heat transfer when studied in conjunction with the flow-field predictions reveal that swirling jets can result in high heat transfer compared to conventional cylindrical jets at low z/d, where the area coverage of swirling jet is smaller than cylindrical jet. With increasing z/d, swirl jet impingement heat transfer showed significant reduction (while increasing coverage) while cylindrical jet impingement primary heat transfer zone was not very sensitive towards it. This is attributed to increased expansion of swirling jet exiting the nozzle at higher z/d, while cylindrical jet retaining its potential core for the z/d range investigated here. Obliquely impinging swirling jet had reduced stagnation zones due asymmetric arrangement of swirl passages with respect to target surface.
A significant focus of behavioral security research has been on understanding employees’ motives for protecting sensitive assets. To date, theorizing efforts in this space have focused on appraisal processes and nomological models that are designed to capture the responses to the security threats articulated within fear appeals. Because fear appeals are persuasive messages used to generate a sense of urgency about a specific threat that influences protective information security behaviors, they are an important focus in behavioral security research. However, we suggest that theoretical guidance is needed to facilitate further research in this area. We argue that ultimately, fear appeals are treatments intended to serve as catalysts of behavioral change. Therefore, fear appeals should have rhetorical validity, which is a specialized form of ecological validity in which contextualization has been included to ensure that the language embedded in the stimulus is consistent with the threat environment and the expectations of its audience. The rhetorical validity of a fear appeal should account for its exigence, the audience, and any constraints that shape the presentation and reception of the discourse. Using the illustrative example of a well-known behavioral security theory, protection motivation theory, this study provides a framework for behavioral security scholars in designing fear appeals that have rhetorical validity.
Safety has been one of the main concerns in the construction industry in recent years. Construction fatalities, injuries, and accidents impose unrecoverable losses and enormous costs every year. Despite all advancements in new methods, tools, equipment, and regulations, the rate of accidents, especially in fatal four, has not considerably improved. This fact has motivated safety professionals and researchers to explore further innovative ways to remedy the problem. One of the outcomes of safety studies is training. Continuous yet effective training can present essential safety knowledge to new employees and refresh the comprehension of current employees. However, such training sessions require funds, time commitment, and logistics. In recent years, the implementation of virtual reality (VR) for safety training has decreased the impact of obstacles and facilitated continuous training. This paper briefly addresses the design and development of a VR module for safety training in the roofing sector. The VR application was entirely designed and developed through an industry-based expert flow, using an agile methodology. A quantitative approach was employed to analyze the data and investigate various aspects of the VR module. The results showed that the VR module positively impacts roofing professionals’ perceptions of the applicability of VR applications as supplementary training tools. The influential factors identified in this research can be considered in the future design and development of VR-based safety applications.
This paper presents a numerical study on the effective thermal conductivity (keff) of architectured materials typically realized through additive manufacturing. Four different unit cell topologies- Cube, Octet, Face-diagonal Cube, and Tetrakaidecahedron, were simulated for a range of porosity values, and both solid- and fluid-phase thermal conductivities. Numerically predicted keff values were validated against the in-house experiments carried out on single-cell thick 5 × 5 unit cell arrangement samples. These simulations led to a correlation for keff as a function of lattice porosity and thermal conductivities of solid- and fluid-phase materials. For the solid-to-fluid thermal conductivity ratio (ks/kf) greater than 300, the keff showed dependence on only the solid thermal conductivity for any given porosity and unit cell topology. The proposed correlation for the keff of architectured materials is applicable to all the four unit cell topologies with porosities > 0.8, and ks/kf ranging from 10² to 10⁴. For these parameters, the correlation can also predict the keff of high-porosity metal foams obtained via foaming process with an accuracy of ±10%.
Carinata is a purpose-grown oilseed feedstock for renewable fuels, including sustainable aviation fuel (SAF) that can replace conventional aviation fuel (CAF). Given carinata is a new crop in the Southeastern United States, it is crucial to analyze its sustainability from a supply chain perspective. This study developed a mixed-integer linear programming (MILP) model and simulated it for 20 years, starting from a farm (county-level data) and ending at the airport. About 2.06 million ha in Alabama, Florida, and Georgia combined were found suitable for carinata production. Given the three-year rotation period, about 0.69 million hectares can be cultivated annually, approximately 65% of which was in Georgia. About 2.4% of the combined SAF annual demand of four major airports (about 210 thousand t) in the study area is satisfied at that level of carinata cultivation. However, all available SAF was supplied to the Atlanta airport as this decision minimizes the supply chain cost. A total of 1343 storage units, one oil extraction mill, and one biorefinery were needed to meet the overall demand. We found that SW Georgia is the top supplier of carinata seeds. The unit cost of production and carbon intensity were estimated to be $0.89 L⁻¹ (or $26.79 GJ⁻¹) and 0.91 kg CO2e L⁻¹ (or 27.28 kg CO2e GJ⁻¹), respectively. This carbon intensity of carinata-based SAF was 67.8% lower than that of CAF. With variations included in SAF demand, yield, and soil carbon sequestration, carbon savings remained between 66.5% and 67.8%. Given the GHG advantage of SAF over CAF, there is justification for subsidies required to make SAF competitive.
E-commerce has been steadily growing year after year, as have the numbers of canceled and returned online orders. Retailers must understand what makes customers second-guess their purchase decision during the gamma phase, and “how” and “why” customers justify their online retail purchase decisions. Purchase justification enables retailers to both enhance positive customer sentiments towards their purchase and maximize profitability in the online context. Utilizing customer survey field data, we illustrate how the combination of evaluative tangibility and anticipatory imagination helps customers justify online hedonic purchases, resulting in both satisfaction and delight. Results indicate that delight but not satisfaction drive share of wallet. We also explore the impact of customers’ previous shopping experiences. Implications for retailer managers and researchers are discussed.
Throughout the southeastern U.S., white-tailed deer (Odocoileus virginianus; hereafter deer) are the dominant herbivores and have the potential to impact vegetation communities through selective browse pressure. Previous studies regarding deer herbivory impacts focused on northeastern and midwestern U.S. forests. Additionally, most studies have observed herbivory effects over short timescales (i.e., <10 years). Therefore, we sought to determine deer herbivory effects on vegetation structure and composition among three different ecoregions in Mississippi at 0, 5, and ∼ 20 years after exclusion. In 2000, 3 pairs of experimental units were identified in each of the Upper Coastal Plain, Lower Coastal Plain, and Mississippi Alluvial Valley ecoregions. An exclosure treatment was randomly assigned within each pair (averaging 2.7 ha) with the other experimental unit a control. From May-June, vegetation structure and composition were measured among 10 systematic sampling points per plot during 2000, 2005, and 2021. While no treatment effects on vegetation composition and structure were observed, among-year differences suggested a shift in overstory canopy conditions between 2005 and 2021 towards greater basal area and canopy coverage resulting in a decrease in forbs, legumes, shade intolerant species, and high year-round deer-preferred forage species. Deer herbivory effects could have been obscured by overstory conditions, low deer densities, and similar baseline conditions reflecting past herbivory effects. Regional differences in forest structure and composition and exclosure breaches may also be responsible for the lack of treatment effects. Future studies should consider utilizing disturbance to offset prior herbivory impacts and to standardize overstory conditions.
Due to fishery-tailored gear, shrimpers are often affected by benthic marine debris, specifically derelict crab traps. To alleviate the impacts on the commercial shrimping industry in the Mississippi Sound, a team of natural resource professionals and stakeholders developed a derelict crab trap removal incentive program for commercial shrimpers. In three years, this program led to the removal of 2904 derelict crab traps from the north-central Gulf of Mexico at a total average cost of $35,595 per year to implement the program, or $53 per derelict crab trap. Results from this study showed the cost of the program could further be reduced while covering the same shrimping area, through the inclusion of fewer disposal locations and targeting active and engaged shrimpers. This program led to the removal of crab traps by non-registered shrimpers, indicating that the existence of the program and associated outreach could lead to improved environmental stewardship without an incentive.
Improving awareness of marine debris could lead to large scale benefits. However, existing marine debris awareness approaches can often be limited in engagement. A more interactive and innovative educational method is needed to increase engagement and action. In this study, we use an immersive Virtual Reality (VR) approach and assess the efficacy and effectiveness of this approach. Three marine debris-related VR modules were developed. To validate the performance VR approach, we compared VR with traditional video-based education. Efficacy measured simulation sickness, system usability, and user experience; effectiveness evaluated knowledge gained and motivation. Twenty-five students were recruited in the study and randomly allocated into two groups. Within the current sample, the developed VR educational approach led to a significantly higher motivation for action and acceptable efficacy performance. These results indicate that VR-based education has the potential to lead to large scale prevention and management of marine debris.
The endomembrane system, functioning in secretion, performs many roles relating to eukaryotic cellphysiological processes and the Golgi apparatus is the central organelle in this system. An essentialassociated Golgi component is the conserved oligomeric Golgi (COG) complex, maintaining correctGolgi structure and function during retrograde trafficking. In animals, naturally occurring cogmutants provide a window into understanding it’s function(s). Eliminating even one COGcomponent impairs its function. In animals, COG mutations lead to severe cell biological anddevelopmental defects and death while far less is understood in plants which is changing. Theplant genetic model Arabidopsis thaliana COG complex functions in growth, cell expansion andother processes, involving direct interactions with other secretion system components includingthe exocyst, soluble N-Ethylmaleimide-Sensitive Factor Attachment Protein Receptor (SNARE), andthe microtubule cytoskeleton. Recent experiments have identified a defense role for the COGcomplex in plants, the focus of this review.
Background Tactical athletes require fast reaction times (RT) along with high levels of vigilance and marksmanship performance. Caffeine has been shown to improve these measures but also results in increased blood pressure and jitteriness. Research on other purine alkaloids, such as methylliberine and theacrine, has suggested they do not increase blood pressure or jitteriness to the same extent, but their impact on tactical performance is unknown. Methods A between-subjects, randomized, placebo-controlled design was used to test the effects of placebo (PLA), 300 mg caffeine (CAF), and a combination of 150 mg caffeine, 100 mg methylliberine, and 50 mg theacrine (CMT) on RT and marksmanship along with hemodynamic and arousal measures following a sustained vigilance task in tactical personnel (n = 48). Following consumption of the supplement, participants underwent a 150-min protocol consisting of two rounds. Each round began with leisurely reading followed by a 30-min vigilance task before beginning two trials of movement and marksmanship tasks. Hemodynamics and felt arousal were assessed throughout the protocol. Composite Z-scores were calculated for overall performance measures at each timepoint, and mixed-effects models were used to assess differences in RT, accuracy, and composite Z-scores along with hemodynamics and felt arousal. An α-level of 0.05 was used to determine statistical significance, and Cohen’s d was used to quantify effect sizes. Results A Group-by-Time interaction for vigilance RT (P = 0.038) indicated improvements for both CAF and CMT from round 1 to round 2 (P < 0.01) while PLA did not change (P = 0.27). No Group main effects or Group-by-Time interactions were found for movement or marksmanship performance (P > 0.20). Group main effects for systolic (SBP; P = 0.001) and diastolic blood pressure (DBP; P = 0.028) indicated higher SBP in CAF (P = 0.003, d= 0.84) and CMT (P = 0.007, d= 0.79) compared to PLA but only higher DBP in CAF (P = 0.025, d= 0.74). No Group-by-Time interaction or Group main effect was found for felt arousal (P > 0.16). Conclusions These findings suggest similar benefits on RT during a vigilance task between CAF, containing 300 mg caffeine, and CMT above PLA, though CAF resulted in slightly less favorable hemodynamic changes. This study is the first to provide data showing similar efficacy of combined caffeine, methylliberine, and theacrine compared to double the caffeine dose consumed alone on vigilance RT but without a significant rise in DBP above PLA in tactical personnel.
A characteristic curve is presented for predicting gross traction of a wheel over a range of powered, towed, and braked modes on clay soils for slip ranging from positive 100% powered slip to negative 100% skid slip. The characteristic curve is a unified approach that relates the ratio of the contact pressure of the wheel to soil strength and predicts the gross traction coefficient over a continuous range of slip. The unified equation is defined by five inflection points: maximum/minimum traction, traction at zero slip, max change in traction with slip, and a shape factor coefficient. The inflection points aim to simplify the calibration of gross traction, slip, soil strength, and contact pressure by using functions adaptable to machine learning. The unified equation is comparable to historic traction equations but is unique in its ability to predict asymmetric braking and powered gross traction. The unified equation is supported and substantiated via error analysis by utilizing the Database Records for Off-road Vehicle Environments (DROVE)-a database constructed around the archived laboratory and field tests for wheels and tracks operating on different soils. The accuracy of the proposed model is assessed and compared to other conventional equations such as the Brixius equation and Maclaurin's extension of the Pacejka equation for off-road traction.
Matric suction is an important parameter controlling the hydro-mechanical behavior of unsaturated soils. Several emerging geotechnical and geoenvironmental applications involve unsaturated soils subject to undrained heating. This study presents a closed-form model to determine the matric suction in unsaturated soils under undrained heating. The final expression is derived based upon the Young–Laplace capillary principle and only needs the soil water retention parameters (i.e., air entry value and pore size distribution) and the enthalpy of immersion at the reference temperature as primary input parameters. Under undrained (constant water) conditions, the closed-form model incorporates the impact of temperature on matric suction by considering the temperature dependency of the liquid-gas interfacial tension, the contact angle of the solid–liquid-gas interface, and the enthalpy of immersion. The model is validated against six sets of experimental data for clay, silt, and sand, reported in the literature. The results show a very good agreement between measured and predicted values for all soil types over a wide range of temperatures. The matric suction monotonically decreases with temperature under undrained heating. The proposed closed-form model can readily be employed in numerical and analytical analyses to simulate the undrained behavior of unsaturated soils under elevated temperatures..
Background The association between adverse childhood experiences (ACEs) and increased risk of health problems is well established. However, many studies have relied on unrepresentative or high-risk samples and have focused on a narrow range of health problems. Prior research assessing potential age differences in the ACE-health connection is also sparse. Objective To comprehensively examine the extent to which ACEs are associated with physical, mental, and neurodevelopmental health outcomes in childhood and assess whether these associations differ between age groups. Participants & setting Pooled cross-sectional data from the 2016–2019 National Survey of Children's Health (N = 98,732). Methods We estimated age-stratified binary logistic regression models examining associations between the number of ACEs and physical, mental, and neurodevelopmental health problems net of sociodemographic and socioeconomic controls. Separate models were estimated for the total population (ages 3–17), early childhood (ages 3–5), middle childhood (ages 6–11), and adolescence (ages 12–17). Results We observed a dose-response relationship between ACE exposure and childhood physical, mental, and neurodevelopmental health problems in all age groups. The largest disparities exist between children with no ACEs and three or more ACEs. Compared to children without ACEs, children with three or more ACEs had significantly higher adjusted odds of externalizing disorders (OR = 4.40), internalizing disorders (OR = 5.13), neurodevelopmental disorders (OR = 2.40), and physical health problems (OR = 2.08). Conclusions Our results add to evidence linking ACEs to childhood health disparities. Further, findings indicate that ACEs have persistent negative effects across age groups and that clinicians should monitor ACEs when assessing children's physical, mental, and neurodevelopmental health at any age.
Naturally forming or mechanically induced hardpans limit water infiltration and crop productivity in many agricultural regions including the Mid-South U.S. This research was conducted to determine whether low-till parabolic subsoiling and furrow irrigation interact to influence soil water dynamics and maize production in the Mid-South. The factorial effects of subsoiling frequency (no subsoiling, NS; subsoiling only before cotton, CS; subsoiling only before maize, MS; and subsoiling every year, ES) × irrigation frequency (no irrigation, NI; low-frequency irrigation, LI; and high-frequency irrigation, HI) on infiltration, grain yield, and profit over specified costs were investigated for the maize portion of a maize-cotton rotation experiment in a silty clay loam soil near Tribbett, Mississippi. Subsoiling before maize improved the infiltration of irrigation (p < 0.05) but not the infiltration of in-season rainfall for irrigated treatments. By subsoiling before maize, high-frequency irrigation maximized grain yield in just one—rather than three—out of five years. Subsoiling before maize also increased non-irrigated yield in all five years. Overall, the combination of subsoiling only before maize and low-frequency irrigation achieved the largest average profit and a relatively small risk. These findings support the practice of low-till parabolic subsoiling before maize as a hydrologically effective and economically viable strategy to conserve freshwater resources in the Mid-South.
Irrigation scheduling methods have been used to determine the timing and amount of water applied to crops. Scheduling techniques can include measurement of soil water content, quantification of crop water use, and monitoring of crop physiological response to water stress. The aim of this study was to evaluate the performance of a simplified crop canopy temperature measurement (CTM) method as Irrigation Principles. Soil and Water Conservation Engineera technique to schedule irrigation for maize. Specifically, the Degrees Above Non-Stressed (DANS) index, which suggests water stress when canopy temperature exceeds the non-stressed canopy temperature (Tcns), was determined by estimating Tcns from a weather based multilinear regression model. The modeled Tcns had a strong correlation with observed Tcns with a pooled R² values of 0.94 across the 2018, 2019, and 2020 growing seasons. This DANS index was also highly correlated with the conventionally used Crop Water Stress Index (CWSI) with R² values of 0.67, 0.59, and 0.76 in 2018, 2019, and 2020, respectively. Furthermore, DANS had a strong linear relationship with soil water depletion above 60% in the 0.60 m soil profile with an R² of 0.78. The CTM method was also compared to more commonly used scheduling methods namely: soil moisture monitoring (SMM) and crop evapotranspiration modeling (ETM). Grain yield was significantly lower for the CTM method than for the ETM method in 2018 and 2020 but not in 2019. No significant differences were observed in Irrigation Water Productivity (IWP) in 2018; however, all treatments were significantly different with the CTM method having the greatest IWP in 2020. For attempting to trigger full irrigation with the CTM method, a fixed DANS threshold of 0.5 °C was found to be more appropriate than the literature value of 1.0 °C, but consideration of crop growth stage would further improve scheduling.
Community college boards of trustees are not highly visible, but they play a vital role in college and student success through governance and oversight of the mission of open access higher education. The stakes are high as community colleges compete for scarce resources in state budgets making the local and state‐level trustee/governing role as fierce advocates of utmost importance. This chapter describes the different roles and functions of community college trustees across the states with a particular focus on college finance. The article begins by describing community college governance arrangements and duties of state level boards followed by a description of duties for locally governed colleges. The chapter then moves to a discussion of state and local budgetary support of community colleges. The chapter closes with a discussion of political power and implications for trustees to expand budgetary support for community colleges through advocacy.
Cellulose nanocrystals (CNC) have been applied in many fields with excellent properties, however, efficient extraction of CNC from biomass materials remains a challenge. This study proposed and evaluated a method for preparing CNC from microcrystalline cellulose (MCC) by combining chemical hydrated deep eutectic solvent (DES) with mechanical high shear force methods. Specifically, when treatment time was increased, the yields of CNC increased from 27.2 % (0.5 h) to 65.2 % (2.5 h). The X-ray diffraction patterns indicate that the obtained CNC possesses the same type of crystal structure as the MCC (cellulose Ι). Transmission Electron Microscopy analyses determined that CNC has an average diameter of 25.1–33.3 nm and a length ranging from 281.3 nm to 404.2 nm. Moreover, the duration of treatment had no significant effect on the changes in morphology and dimension of CNC. This method is more eco-friendly than conventional hydrolysis, as well as faster than other DES treatments, which paves the way for CNC to be produced from MCC.
Mobile infrared thermometers (IRTs) mounted on moving platforms provide one-time-of-day radiometric measurements (Tr), which can be used to calculate instantaneous actual evapotranspiration (ETa) using the two-source energy balance (TSEB) model. However, irrigation scheduling decisions utilize daily ETa estimates, hence the need for time scaling. This study evaluated different upscaling methods to calculate daily maize ETa using one-time-of day Tr under varying water stress conditions. Mobile IRTs were mounted on a high clearance mobile sensing platform and collected Tr in remote locations under full, deficit and rainfed conditions. Seven scaling methods via two pathways were employed to obtain daily ETa. First pathway was scaling one-time-of-day Tr (SC) whereas the second pathway involved use of six upscaling methods of instantaneous ETa including: original and modified evaporative factor ((EF)o, (EF)m) as well as crop coefficient ((Kc)o, (Kc)m), direct canopy resistance (Direct- rc), and solar radiation ratio (Rn/Rs); and all were compared to a neutron-based soil water balance (SWB) determined ETa. From the results, SC outperformed other methods in comparison to SWB ETa across all the selected treatments with smaller discrepancies and lower RMSE (0.9–1.7 mm d⁻¹ vs. 0.7–4.3 mm d⁻¹ for other methods). Furthermore, methods including SC, (EF)o, (EF)m, and Rn/Rs had their daily average ETa values in close agreement to SWB ETa with mean ETa differences ranging between 0.2 and 1.6 mm d⁻¹. Overall, SC method performed better in fully irrigated maize (r² = 0.52, RMSE = 0.9 mm d⁻¹) than in deficit irrigated maize ( r² = 0.48, RMSE = 1.4 mm d⁻¹) but worst in rainfed maize (r² = 0.16, RMSE = 1.7 mm d⁻¹). This implies that SC is more suited for irrigated rather than rainfed settings. Importantly, the choice of any method depends on data requirements, irrigation water management strategy, and ETa estimation accuracy.
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5,868 members
Arazais D. Oliveros
  • Department of Psychology
Cliff Mckinney
  • Department of Psychology
Robert Meyer
  • College of Veterinary Medicine
Vladimir J. Alarcon
  • Northern Gulf Institute (NGI)
Department of Wildlife, Fisheries and Aquaculture, 775 Stone Blvd, 39762, Starkville, Mississippi, United States
Head of institution
Dr. Mark Keenum