Calibrattions of Cold-Formed Steel Welded Connections

The purpose of this project was to recalibrate the welded connection equations currently contained in the American Iron and Steel Institute (AISI) Specification for the Design of Cold Formed Steel Structural Members (AISI 1996a). Only one factor of safety of 2.50 is presented for the each of the various types of welded connections when using allowable stress design (ASD), but different respective resistance factors are given for load and resistance factor design (LRFD). The data used was solely taken from the research conducted by Pekoz and McGuire (Pekoz and McGuire 1979). Calibrations were carried out and based on both the AISI Specification (AISI 1996a) and the Canadian Sl36 Standard (CSA 1994). The results of this study have already been adopted by both of these cold formed steel design agencies, as well as by the North American Specification for the Design of Cold-Formed Steel Structural Members (NAS 2001)

Vibration Characteristics of Lightweight Floors Using Cold-formed Steel Joist

Presented in this paper are the results of a recent study carried out at the University of Waterloo on vibration characteristics of cold-formed steel-supported residential floor systems and different design criteria available for the evaluation of lightweight floor systems. Laboratory tests were conducted for the floors with different spans and assemblies. Both static and dynamic tests were carried out on the floor systems. The static tests were used to evaluate the stiffness and the load sharing among the joists, while the dynamic tests were used to evaluate the relevant dynamic characteristics, such as natural frequencies and damping ratios, of the floor systems. The test results were then compared with those obtained from different design methods. Concluding remarks regarding the acceptance criteria from the comparison are also presented

Design and testing of a GPS/GSM collar prototype to combat cattle rustling

Rustling is an age-old practice that was widespread in Italy until the first half of the 20th century. Today, incidents of cattle rustling are again being reported. However, the problem is not only found in Italy. It is also becoming a plague for ranchers in the US and is still rampant in East Africa. In Italy, the cattle rustling phenomena have usually been limited through the direct control of the herdsmen. Global positioning system (GPS) and geographic information system (GIS) combined technologies are increasingly applied for tracking and monitoring livestock with greater spatial and temporal resolution. However, so far, no case studies of the use of GPS technology to combat cattle rustling have been reported in the literature. The aim of this research was to develop a GPS/GSM (global system for mobile communication) collar, using commercial hardware and implementing a specific software [ARVAshepherd 1.0; ARVAtec Srl, Rescaldina (MI), Italy] to track animals' movements outside their grazing area and to signal when animals are straying outside virtual perimeters. A phase I study was conducted from January to June 2011 to build the GPS/GSM collar and to assess its performances in terms of GPS accuracy and precision, while a phase II study was conducted in July 2011 to test the GPS collar under real-life operating conditions. The static GPS positioning error achieved a circular error probable (50%) and horizontal 95% accuracy of 1.462 m and 4.501 m, respectively. This is comparable with values obtained by other authors in static tests of a commercial GPS collar for grazing studies. In field tests, the system was able to identify the incorrect position of the cattle and the warning messages were sent promptly to the farmer, continuing until the animals had been repositioned inside the fence, thus highlighting the potential of the GPS/GSM collar as an anti-theft system

Una visión bentónica de arroyos y ríos pampeanos

In this paper, Tributaries of the Río Paraná and Río de la Plata rivers (Arrecifes and Matanza-Riachuelo rivers, El Gato, El Pescado, Juan Blanco and Buriñigo streams). The System of Río Salado (Samborombón and Salado rivers, Las Garzas stream) and streams of Tandilia gills north-eastern slope stream (Napaleofú, Langueyú, Tandileofú, Chelforó and Vivoratá) were studied by analysing the zoobenthic community. Several streams tributaries of Rio de la Plata river are affected (to a different extent) by urban and industrial perturbations and they were compared with pristine streams of the region. Diversity and Biotic Indices were applied in the streams. Tolerant species and slow scores of the both indices were mainly registered in Matanza-Riachuelo river and El Gato stream, and the more sensitive taxa were identified in El Pescado and Juan Blanco streams. In Samborombon river there were salinity changes with taxa adapted to this condition (Polichaeta, Chasmagnatus granulata, Cyrtograpsus angulata, Cirripedia.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

Una visión bentónica de arroyos y ríos pampeanos

In this paper, Tributaries of the Río Paraná and Río de la Plata rivers (Arrecifes and Matanza-Riachuelo rivers, El Gato, El Pescado, Juan Blanco and Buriñigo streams). The System of Río Salado (Samborombón and Salado rivers, Las Garzas stream) and streams of Tandilia gills north-eastern slope stream (Napaleofú, Langueyú, Tandileofú, Chelforó and Vivoratá) were studied by analysing the zoobenthic community. Several streams tributaries of Rio de la Plata river are affected (to a different extent) by urban and industrial perturbations and they were compared with pristine streams of the region. Diversity and Biotic Indices were applied in the streams. Tolerant species and slow scores of the both indices were mainly registered in Matanza-Riachuelo river and El Gato stream, and the more sensitive taxa were identified in El Pescado and Juan Blanco streams. In Samborombon river there were salinity changes with taxa adapted to this condition (Polichaeta, Chasmagnatus granulata, Cyrtograpsus angulata, Cirripedia.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

The Use of Infrared Thermography fort he Monitoring of Udder Teat Stress Caused by Milking Machines

The aim of this study was to test infrared thermography (IRT) as a possible tool for scoring teat color changes after cluster removal; thus, indirectly, to classify the short-term stress of teats caused by milking machines. Thermographic images (n = 137) from three farms were collected and evaluated to calculate the average and maximum skin surface temperatures (SSTs) at the base, center, and tip of each teat (Tavg,B, Tavg,C, Tavg,T, Tmax,B, Tmax,C, and Tmax,T). Obtained results confirmed a significant relationship between the indicators Tavg, Tmax and the levels of teat color change (level one: pink-colored teat; level two: red-colored teat; level three: blue or purple-colored teat). Nevertheless, when a teat was considered to be stressed because its scoring fell in level 3 of the color-change scale used, sensitivity and specificity in the classification of the teat status ranged respectively between 45.6% and 54.3%, and 54.4% and 59.2%, for the indicators Tavg; and 56.5% and 60.9%, and 59.7% and 61.8%, for the indicators Tmax. When a teat was considered stressed because its scoring fell between the levels 2 and 3 of the scale adopted, sensitivity and specificity were between 49.0% and 55.8%, and 58.3% and 61.8%, for the indicators Tavg; and 55.8% and 59.9%, and 60.6% and 61.4%, for the indicators Tmax. As a consequence, the low values of sensitivity and specificity do not seem to justify the development of an ad hoc infrared device for the monitoring of udder teat stress. Nonetheless, this technology can be a viable solution for a preliminary evaluation of the mechanical stress of teats if a milking system would be equipped with an infrared sensor already in place for other purposes (e.g., the monitoring of udder health status)

Meccanica agraria e zootecnia: mungitura robotizzata, analisi dei consumi energetici

Negli ultimi trent\u2019anni le produzioni zootecniche sono state caratterizzate da un intenso sviluppo tecnologico al quale la Meccanica Agraria ha contribuito fortemente giocando un ruolo fondamentale nell\u2019incrementare la produttivit\ue0 del lavoro, garantire e migliorare il benessere animale, assicurare un\u2019intensificazione sostenibile dei processi produttivi. L\u2019automazione delle operazioni di stalla e in particolare della mungitura, che rappresenta la fase pi\uf9 onerosa in termini economici e fisici, e per la quale non pu\uf2 ancora ritenersi concluso il processo evolutivo, \ue8 probabilmente l\u2019ambito in cui il Meccanico Agrario che opera in contesti zootecnici \ue8 maggiormente coinvolto. Ad oggi nel mondo sono installati circa 45.000 sistemi automatici di mungitura o AMS (Automatic Milking System), di cui oltre 700 in Italia, e questo numero \ue8 destinato a crescere nei prossimi anni nel contesto di una generale tendenza all\u2019automazione della stalla da latte, aumentando il consumo energetico relativo alla mungitura robotizzata. L\u2019energia utilizzata da un AMS dipende da molti fattori, tra cui la generazione di appartenenza, le configurazioni e le impostazioni della macchina, nonch\ue9 le condizioni operative. Il lavoro qui presentato ha avuto come scopo quello di misurare e analizzare il consumo elettrico di due generazioni successive di AMS installati in aziende da latte del nord Italia, caratterizzate da contesti operativi diversi. La prova sperimentale \ue8 stata condotta su quattro AMS con differenti configurazioni (stallo singolo, unit\ue0 centrale con una o due unit\ue0 di mungitura). Il consumo elettrico (giornaliero, giornaliero per bovina munta, per mungitura, per 100 litri di latte) di ogni AMS (unit\ue0 di mungitura e compressore dell\u2019aria) \ue8 stato misurato utilizzando due multimetri collegati ai quadri elettrici rispettivamente dell\u2019AMS e del compressore dell\u2019aria. Il periodo di misura \ue8 stato di 24 h per ciascun sistema, utilizzando una frequenza di campionamento di 0,2 Hz. Il consumo elettrico degli AMS \ue8 risultato condizionato principalmente dalla gestione aziendale piuttosto che dalle caratteristiche e architetture delle singole macchine

Prevalence of micronutrient deficiency in popular diet plans

<p>Abstract</p> <p>Background</p> <p>Research has shown micronutrient deficiency to be scientifically linked to a higher risk of overweight/obesity and other dangerous and debilitating diseases. With more than two-thirds of the U.S. population overweight or obese, and research showing that one-third are on a diet at any given time, a need existed to determine whether current popular diet plans could protect followers from micronutrient deficiency by providing the minimum levels of 27 micronutrients, as determined by the U.S. Food and Drug Administrations (FDA) Reference Daily Intake (RDI) guidelines.</p> <p>Methods</p> <p>Suggested daily menus from four popular diet plans (<it>Atkins for Life </it>diet, <it>The South Beach Diet</it>, <it>the DASH diet</it>, <it>the DASH diet</it>) were evaluated. Calorie and micronutrient content of each ingredient, in each meal, were determined by using food composition data from the U.S. Department of Agriculture Nutrient Database for Standard Reference. The results were evaluated for sufficiency and total calories and deficient micronutrients were identified. The diet plans that did not meet 100% sufficiency by RDI guidelines for each of the 27 micronutrients were re-analyzed; (1) to identify a micronutrient sufficient calorie intake for all 27 micronutrients, and (2) to identify a second micronutrient sufficient calorie intake when consistently low or nonexistent micronutrients were removed from the sufficiency requirement.</p> <p>Results</p> <p>Analysis determined that each of the four popular diet plans failed to provide minimum RDI sufficiency for all 27 micronutrients analyzed. The four diet plans, on average, were found to be RDI sufficient in (11.75 ± 2.02; mean ± SEM) of the analyzed 27 micronutrients and contain (1748.25 ± 209.57) kcal. Further analysis of the four diets found that an average calorie intake of (27,575 ± 4660.72) would be required to achieve sufficiency in all 27 micronutrients. Six micronutrients (vitamin B7, vitamin D, vitamin E, chromium, iodine and molybdenum) were identified as consistently low or nonexistent in all four diet plans. These six micronutrients were removed from the sufficiency requirement and additional analysis of the four diets was conducted. It was determined that an average calorie content of (3,475 ± 543.81) would be required to reach 100% sufficiency in the remaining 21 micronutrients.</p> <p>Conclusion</p> <p>These findings are significant and indicate that an individual following a popular diet plan as suggested, with food alone, has a high likelihood of becoming micronutrient deficient; a state shown to be scientifically linked to an increased risk for many dangerous and debilitating health conditions and diseases.</p