Silo construction

The value of the silo as a means of utilizing almost the entire corn plant and producing valuable feed has been thoroly demonstrated. Silage is an economical and desirable feed and it is highly desirable that the use of the silo be more generally adopted. The construction of silos has been for many years one of the principal lines of investigation followed by the Agricultural Engineering Section of the Iowa Agricultural Experiment Station. Results have been published in the following bulletins: No. 100, July, 1908, revised and republished July, 1909; No. 117, June, 1910, by J. B. Davidson and M. L. King, and No. 141, June, 1913, by J. B. Davidson. This new bulletin No. 189 is a revision of Bulletin No. 141. The Agricultural Engineering Section does not recommend any one type of silo above all others. It has been demonstrated by experience that a number of different types of silos will each give satisfactory service if properly constructed. It is well worth while for the silo builder to study the types and details of construction which will insure a reasonably permanent structure

Curing Hay in the Barn

Making hay in the barn isn’t exactly new. But only a few farmers have equipment for doing it. This method of making hay—curing it in the mow—was tried more than 10 years ago by the Tennessee Valley Authority

Dryer Corn Means Safer Storage

Today\u27s farmer has dozens of corn varieties to choose from. Unfortunately, most of the highest-yielding varieties need a long growing season. That means you may be taking some risk in choosing a high-yielding variety. If your planting is delayed by wet weather, if the summer is cool or if there\u27s not good drying weather in the fall, you may have the problem of storing corn that\u27s not dry enough for ordinary crib storage

We Have Some Soft Corn

Many Iowa farms have a lot of soft corn, and most farms have corn with high moisture content to be taken care of this fall. The wet spring and the necessity of replanting many fields made this unavoidable. The problem now is how best to handle it

The Influence of Equilibrium Reactions on the Kinetics of Calcite Dissolution in Lactic Acid Solutions

Matrix acidizing has historically been a common means of removing formation damage and increasing the productivity of petroleum wells. Organic acids have been used in an effort to minimize the corrosion problem and the rapid reaction rate encountered when using strong acids, such as hydrochloric acid (HCl). The reaction of an organic acid with carbonates is reversible and thermodynamically limited by the presence of reaction products. This thermodynamic limitation must be considered when studying the reaction kinetics of organic acids with carbonates. A kinetic model was developed to account for both the equilibrium reactions on the rock surface and the mass transfer of the reactants and products. This study provides both mass transport and reaction kinetics parameters, which can be combined with the reservoir temperature to determine treatment duration or soaking time. While lactic acid has been used successfully in the field, having a more detailed knowledge of the reaction between lactic acid and calcite will allow for optimized treatment design. The kinetic model was also used to isolate the contributions of the transport of reactants, the surface reaction, and the transport of products to the overall resistance of the reaction. At all temperatures investigated, the transport of products away from the surface represented the largest contribution to overall resistance. A coreflood experiment was also performed to observe and confirm the wormholing tendencies of lactic acid in calcite. Lactic acid formed a single dominant, minimally-branched wormhole through the core

Applications of Commercial Heat Pump Water Heaters in Hot, Humid Climates

Heat pump water heaters can provide high-efficiency water heating and supplemental space cooling and dehumidification in commercial buildings throughout the United States. They are particularly attractive in hot, humid areas where cooling loads are high and the cooling season is long. Because commercial kitchens and laundry facilities have simultaneous water heating and cooling needs, they are excellent applications for heat pump water heaters. Typical heat pump water heaters (HPWHs) operate at an annual coefficient of performance (COP) of approximately 3.0 for water heating alone. Space conditioning benefits of about 0.67 Btu are delivered at no additional cost for each Btu of water heating output. In situations in which this cooling output is valued, the dual thermal outputs for heating and cooling make heat pump water heaters particularly attractive. The comfort value of added cooling in overheated facilities and the resulting increase in employee and customer satisfaction are frequently cited as additional benefits. This paper describes currently available heat pump water heating equipment and offers guidelines for successful applications in commercial facilities. The results of field test programs involving more than 100 units in Alabama, Georgia, Mississippi, Tennessee, South Carolina, and other areas are incorporated. Initial conclusions are drawn from a reliability database, and interviews with utility applications specialists and manufacturers are discussed. Design tools are reviewed, including a new comprehensive computer simulation model. Emphasis is placed on identifying sound candidates for installations and on application and design considerations. A brief survey is provided of environmental implications of heat pump water heaters and new developments in heat pump water heater equipment

Electron Wave Function in Armchair Graphene Nanoribbons

By using analytical solution of a tight-binding model for armchair nanoribbons, it is confirmed that the solution represents the standing wave formed by intervalley scattering and that pseudospin is invariant under the scattering. The phase space of armchair nanoribbon which includes a single Dirac singularity is specified. By examining the effects of boundary perturbations on the wave function, we suggest that the existance of a strong boundary potential is inconsistent with the observation in a recent scanning tunneling microscopy. Some of the possible electron-density superstructure patterns near a step armchair edge located on top of graphite are presented. It is demonstrated that a selection rule for the G band in Raman spectroscopy can be most easily reproduced with the analytical solution.Comment: 7 pages, 4 figure

Effect of mechanical preconditioning on the electrical properties of knitted conductive textiles during cyclic loading

This paper presents, for the first time, the electrical response of knitted conductive fabrics to a considerable number of cycles of deformation in view of their use as wearable sensors. The changes in the electrical properties of four knitted conductive textiles, made of 20% stainless steel and 80% polyester fibers, were studied during unidirectional elongation in an Instron machine. Two tests sessions of 250 stretch–recovery cycles were conducted for each sample at two elongation rates (9.6 and 12 mm/s) and at three constant currents (1, 3 and 6 mA). The first session assessed the effects of an extended cyclic mechanical loading (preconditioning) on the electrical properties, especially on the electrical stabilization. The second session, which followed after a 5 minute interval under identical conditions, investigated whether the stabilization and repeatability of the electrical features were maintained after rest. The influence of current and elongation rate on the resistance measurements was also analyzed. In particular, the presence of a semiconducting behavior of the stainless steel fibers was proved by means of different test currents. Lastly, the article shows the time-dependence of the fabrics by means of hysteresis graphs and their non-linear behavior thanks to a time–frequency analysis. All knit patterns exhibited interesting changes in electrical properties as a result of mechanical preconditioning and extended use. For instance, the gauge factor, which indicates the sensitivity of the fabric sensor, varied considerably with the number of cycles, being up to 20 times smaller than that measured using low cycle number protocols

Recommendations for a national agenda to substantially reduce cervical cancer

PURPOSE: Prophylactic human papillomavirus (HPV) vaccines and new HPV screening tests, combined with traditional Pap test screening, provide an unprecedented opportunity to greatly reduce cervical cancer in the USA. Despite these advances, thousands of women continue to be diagnosed with and die of this highly preventable disease each year. This paper describes the initiatives and recommendations of national cervical cancer experts toward preventing and possibly eliminating this disease. METHODS: In May 2011, Cervical Cancer-Free America, a national initiative, convened a cervical cancer summit in Washington, DC. Over 120 experts from the public and private sector met to develop a national agenda for reducing cervical cancer morbidity and mortality in the USA. RESULTS: Summit participants evaluated four broad challenges to reducing cervical cancer: (1) low use of HPV vaccines, (2) low use of cervical cancer screening, (3) screening errors, and (4) lack of continuity of care for women diagnosed with cervical cancer. The summit offered 12 concrete recommendations to guide future national and local efforts toward this goal. CONCLUSIONS: Cervical cancer incidence and mortality can be greatly reduced by better deploying existing methods and systems. The challenge lies in ensuring that the array of available prevention options are accessible and utilized by all age-appropriate women-particularly minority and underserved women who are disproportionately affected by this disease. The consensus was that cervical cancer can be greatly reduced and that prevention efforts can lead the way towards a dramatic reduction in this preventable disease in our country