A Second Language Acquisition Toolkit for Teaching Introduction to Computing

Introduction to Computing and higher-level programming courses are common first-year engineering curricula at the university level and are key in developing logical thought processes in engineering students. Recent research has shown that employing second language acquisition (SLA) techniques to teach programming increases exam performance and student motivation compared to more classical approaches. However, the presentation of pedagogical techniques has been largely limited to higher-level languages with more intuitive linguistic analogs and has not been extended to lower-level computing course material. In this paper we present several SLA techniques and their analogs in a computing course setting and the results of implementing an SLA strategy in a first-year engineering course. Statistical analysis shows that students taught with SLA methods completed quizzes more quickly, enjoyed recitation more, and had a higher perceived value of the class when compared with students taught with non-SLA techniques.Cockrell School of Engineerin

"Willingness to Pay for Electric Vehicles and their Attributes"

This article presents a stated preference study of electric vehicle choice using data from a national survey. We used a choice experiment wherein 3029 respondents were asked to choose between their preferred gasoline vehicle and two electric versions of that preferred vehicle. We estimated a latent class random utility model and used the results to estimate the willingness to pay for five electric vehicle attributes: driving range, charging time, fuel cost saving, pollution reduction, and performance. Driving range, fuel cost savings, and charging time led in importance to respondents. Individuals were willing to pay (wtp) from $35 to$75 for a mile of added driving range, with incremental wtp per mile decreasing at higher distances. They were willing to pay from $425 to$3250 per hour reduction in charging time (for a 50 mile charge). Respondents capitalized about 5 years of fuel saving into the purchase price of an electric vehicle. We simulated our model over a range of electric vehicle configurations and found that people with the highest values for electric vehicles were willing to pay a premium above their wtp for a gasoline vehicle that ranged from $6000 to$16,000 for electric vehicles with the most desirable attributes. At the same time, our results suggest that battery cost must drop significantly before electric vehicles will find a mass market without subsidy.Electric Vehicles, Stated Preference, Discrete Choice

"Can Vehicle-to-Grid Revenue Help Electric Vehicles on the Market?"

Vehicle-to-grid (V2G) electric vehicles can return power stored in their batteries back to the power grid and be programmed to do so at times when power prices are high. Since providing this service can lead to payments to owners of vehicles, it effectively reduces the cost of electric vehicles. Using data from a national stated preference survey (n = 3029), this paper presents the first study of the potential consumer demand for V2G electric vehicles. In our choice experiment, 3029 respondents compared their preferred gasoline vehicle with two V2G electric vehicles. The V2G vehicles were described by a set of electric vehicle attributes and V2G contract requirements such as “required plug-in time” and “guaranteed minimum driving range”. The contract requirements specify a contract between drivers and a power aggregator for providing reserve power to the grid. Our findings suggest the V2G concept is mostly likely to help EVs on the market if power aggregators operate on pay-as-you-go-basis or provide consumers with advanced cash payment (upfront discounts on the price of EVs) in exchange for V2G restrictions.electric vehicles, vehicle-to-grid, stated preference, latent-class model

Terdiurnal Oscillations in OH Meinel Rotational Temperatures for Fall Conditions at Northern Mid-latitude Sites

High‐precision (∼0.5 K) measurements of OH Meinel (M) (6,2) rotational temperatures above the Bear Lake Observatory, UT (42°N, 112°W) during October 1996 have revealed an interesting and unexpected mean nocturnal pattern. Ten quality nights (\u3e100 h) of data have been used to form a mean night for autumnal, near‐equinoctial conditions. The mean temperature and RMS variability associated with this mean night were 203 ± 5 K and 2.4 K, respectively, and compare very favorably with expectations based on Na‐lidar measurements of mean tidal temperature perturbations over Urbana, IL (40°N, 88°W) during the fall 1996. Furthermore, this comparison shows that the 8‐h tide was the dominant source of the mean nocturnal temperature variability in the OH M region during this period. Additional data, obtained at Fort Collins, CO (41°N, 105°W) in November 1997, illustrate the occurrence of an 8‐h component of OH temperature variability about two months after the equinox and show that daily amplitudes as high as ≅15 K are possible

Relation between Childhood Obesity and Adult Cardiovascular Risk

The incidence of overweight and obesity is rising at an alarming pace in the pediatric population, just as in the adult population. The adult comorbidities associated with this risk factor are well-recognized and are being further elucidated continually. Additionally, we are gradually developing a better understanding of the risks of overweight and obesity among children while they are still young. However, there is now a growing body of evidence showing that childhood obesity not only leads all too frequently to adult obesity, but is in itself a risk factor for cardiometabolic syndrome and resultant cardiovascular risk in adulthood. If current trends continue, the problem of pediatric overweight and obesity will become of unmanageable proportions once these individuals reach adulthood. Future research efforts toward understanding this complex problem will need to focus on those overweight and obese children who later went on to change their metabolic course and become normal-weight adults

Maximum Penetration of Atmospheric Gravity Waves Observed During ALOHA-93

Atmospheric Gravity Waves (AGWs) are subject to altitude propagation limits which are governed by the diffusion processes. Diffusion times and scales which exceed the wave period and wavelength define the limiting domain for AGWs. An expression is presented which defines the upper altitude limit to which AGWs can propagate given vertical diffusion constraints of the atmosphere. Airglow, lidar, and radar measurements are combined to characterize the intrinsic AGW parameters in the 80–105 km altitude region. A subset of AGWs (17) observed by airglow imagers during the ALOHA‐93 were made when simultaneous wind measurements were available and intrinsic wave parameters were calculated. The limiting altitude of propagation for these measured monochromatic waves is calculated to range from 110–150 km (with a mean limiting altitude of 130 km). The altitude limit is necessarily lower for waves with short vertical wavelengths and longer intrinsic periods. This observation is important for a large number of issues including energetic considerations regarding thermospheric heating in models which consider upward propagating AGWs (and energy flux) of tropospheric origin. This limited data base should be expanded for statistical significance in future work

Full-wave Modeling of Small-scale Gravity Waves using Airborne Lidar and Observations of the Hawaiian Airglow (ALOHA-93) O(¹S) Images and Coincident Na Wind/temperature Lidar Measurements

Measurements were made of mesospheric gravity waves in the OI (5577 Å) nightglow observed from Maui, Hawaii, during the Airborne Lidar and Observations of Hawaiian Airglow (ALOHA-93) campaign. Clear, monochromatic gravity waves were observed on several nights. By using a full-wave model that realistically includes the major physical processes in this region, we have simulated the propagation of four waves through the mesopause region and calculated the O(¹S) nightglow response to the waves. Mean winds derived from Na wind/temperature lidar observations were employed in the computations. Wave amplitudes were calculated based on the requirement that the observed and simulated relative airglow fluctuation amplitudes be equal. Although the extrinsic (i.e., observed) characteristics of all four waves studied were quite similar (horizontal wavelengths ∼20 to 30 km; periods ∼9 min; horizontal phase speeds ∼35 to 50 m s¯¹), the propagation characteristics of the waves are all quite different due to the different background mean winds through which the waves propagate. Three of the waves encounter critical levels in the mesopause region. For two of these waves the upward propagation beyond the 97 km level is severely impeded by their critical levels because the local value of the Richardson number exceeds unity there. The third wave is not severely attenuated at its critical level because the Richardson number there is about 0.25. The fourth wave does not encounter a critical level although it is strongly Doppler shifted to low frequencies over a limited height range by the mean winds. It appears to be able to propagate at least to the 110 km level essentially unimpeded. This study demonstrates that an accurate description of the mean winds is an essential requirement for a complete interpretation of observed wave-driven airglow fluctuations. The study also emphasizes that although the measured extrinsic properties of waves may be similar, their propagation to higher altitudes depends very sensitively on the mean winds through which the waves propagate

Iodine status of soils, grain crops, and irrigation waters in Pakistan

A study was carried out across 86 locations of the country to investigate iodine supply potential of soils, grains and underground waters for onward design of an environmental intervention in Pakistan. Wheat crops were the principal crop in this study since it supplies 75 % of calorific energy in an average Pakistani diet. TMAH-extractable iodine in soils provided a geometric mean of 0.66 µg g−1, far lower than the worldwide mean of 3.0 µg g−1 for soil iodine. Bioavailable (water-extractable) iodine concentration had a geometric mean of 2.4 % (of TMAH-extractable iodine). Median iodine concentrations in tube well sourced waters were 7.3 µg L−1. Median wheat grain-iodine concentrations were 0.01 µg g−1. In most of the grain samples, TMAH-extractable iodine was below detection limit of 0.01 µg g−1. The highest wheat grain iodine was measured on a soil having highest TMAH-extractable iodine. An iodine intake of 25.4 µg a day has been estimated based on median wheat grain iodine measured and groundwater consumption compared to world health organisation (WHO) recommendations of iodine intake of 150 µg a day. This nominal intake of iodine is alarming since 60 % of Pakistani households do not consume iodised salt