Calibrating the APEX Model for Simulations of Environmental and Agronomic Outcomes on Dairy Farms in the Northeast U.S.: A Step-by-Step Example

2020 ◽  
Vol 36 (3) ◽  
pp. 281-301
Author(s):  
Rachel Mason ◽  
Josef Gorres ◽  
Joshua W. Faulkner ◽  
Luca Doro ◽  
Scott C. Merrill
Keyword(s):  
Crop Yields ◽  
Dairy Farm ◽  
Dairy Farms ◽  
List Type ◽  
Point Of Entry ◽  
Modeling Methodology ◽  
Decision Points ◽  
Starting Point ◽  
Calibration Methods ◽  
Apex Model

HighlightsThis article details the method used to calibrate the APEX model for simulations of dairy farm silage corn production.Useful model outputs, plots, and metrics are discussed, as well as decision points and potential improvements.The article is intended as a helpful starting point for those who are new to APEX.Abstract. This article documents the procedure used to calibrate the Agricultural Policy/Environmental eXtender (APEX) model for a project that aimed to simulate crop yields, runoff, erosion, and nutrient losses on dairy farms under climate change. We describe each step in the calibration process, presenting the model outputs, plots, and metrics that were found to be useful, and discussing the decisions that needed to be made along the way. Calibration improved the performance of the model relative to an uncalibrated “baseline” version, and 0.22 < NSE < 0.49 and PBIAS within ±12% were achieved for most of the model outputs. While the mean annual silage yield was correct (PBIAS = 2%), the model did not accurately capture year-to-year yield variations (NSE = -1.6), and results for nitrogen in runoff were poor (NSE = -0.04, PBIAS = -69%).We therefore also outline several ways in which the method could be improved. Other calibration methods exist, and the procedure presented here will not be applicable in all situations. However, fully documented APEX calibrations are rare in the literature, and the number of non-expert model users may be growing. We therefore anticipate that this paper will serve as a useful point of entry for those who are new to APEX. We also hope that this work contributes to the development of transparent and reproducible procedures for modeling studies that have real-world implications. Keywords: APEX model, Hydrologic modeling, Methodology, Model calibration.

scholarly journals IAU Commission 25, and the development of early photometric systems

2018 ◽  
Vol 13 (S349) ◽  
pp. 357-373
Author(s):  
Christiaan Sterken
Keyword(s):  
List Type ◽  
Basic Principles ◽  
Half Century ◽  
Stellar Photometry ◽  
Select Group ◽  
International Astronomical ◽  
Calibration Methods ◽  
Standard Calibration ◽  
One Year ◽  
Basic Philosophy

AbstractThe International Astronomical Union was conceived in 1918, and was formed one year later in Brussels. One of the 32 initial Commissions was the Committee on Stellar Photometry that later on became IAU Commission 25 Astronomical Photometry and Polarimetry, and since 2015 Commission B6 with the same name. The initial functions to be exercised by the Committee were (a)to advise in the matter of notation, nomenclature, definitions, conventions, etc., and(b)to plan and execute investigations requiring the cooperation of several observers or institutions.The basic philosophy was that IAU Commission 25 was to be an advisory body, rather than a decision-making committee that imposes its regulations. This position was reconfirmed at the 10th IAU General Assembly in 1958.From the early days on, the Commission members engaged in the teaching of the principles of photometric measurement – either via the Commission meetings and the ensuing reports, or via external means, such as lectures and publications. The topics of instruction dealt with absorption of light in the atmosphere, the modification imposed by the character of the receiving apparatus, the unequal response of different receivers to a same stimulus, and variations in the data-recorder response from one experiment to another.From the 1930s on it was suggested that IAU Commission 25 takes responsibility in matters of standard stars, standard filters and standard calibration methods.During the first half-century since its foundation, Commission 25 was an active forum for discussions on the basic principles of astronomical photometry, including the associated problems of transformability of magnitudes and colour indices from one instrumental configuration to another. During the second half-century of its existence, the Commission has served as a sort of news agency reporting on the developments in detector engineering, filter technology and data reduction. All along the Commission members were committed to accuracy and precision, a struggle that was primarily driven by the jumps forward in performance and sensitivity of every new detector that was introduced.The development over one century shows that the Commission was continuously touching on the philosophy of precise measurement, where accurate measuring – for a select group of pioneers – was an end in itself.This presentation looks back on the opinions of key players in the photometric standardisation debate, and briefly presents two case studies that illustrate the illusionary accuracy reached over a century in determining, as Commission member Ralph Allan Sampson put it, “a detail like magnitude”.

Rising from the ashes: Satyam's story

2014 ◽  
Vol 4 (1) ◽  
pp. 1-8
Author(s):  
Tanvi Gautam
Keyword(s):  
Change Management ◽  
Subject Area ◽  
Executive Education ◽  
List Type ◽  
Corporate Communications ◽  
It Industry ◽  
Market Reactions ◽  
Content Type ◽  
Employee Trust ◽  
Starting Point

Subject area Leadership, human resource management, crisis management, change management and communication. Study level/applicability Executive education; postgraduate; undergraduate. Case overview This case study describes the collapse of Satyam, a leading IT industry service provider from India. Satyam went into a crisis mode after revelation of financial fraud by its Chairman. This resulted in a crisis not just for the company, its clients and employees – but it also had the potential to shake up the entire Indian IT industry the world over, by shattering investor and client confidence in the Indian IT sector. The case provides the students with an inside view of the unfolding of events at Satyam and the people challenges that emerge in a crisis scenario. The case outlines reactions from the industry, government, clients and employees as they tried to make sense of a very chaotic situation, and its multi-level ramifications both within India and outside. The case ends with Thallapalli Hari, the Global Head of Marketing and Communication and ex-head of HR, trying to visualise and prioritise a course of action to propose to other members of the leadership team. Expected learning outcomes The key aim of this case is to provide a backdrop to the crisis, and also help students put themselves in the role of an HR crisis manager as well as portray the decision making and communication challenges that emerge in chaotic situations. The importance of an immediate and yet strategic response is emphasised and the case is a great starting point to have a discussion on the competencies and skills required in HR to lead under unusual circumstances. This case allows participants to get an in-depth understanding of the collapse of Satyam. The case also illustrates principles of leadership, change management and communication, in particular: Leadership: The Satyam story is an HR and leadership crisis nightmare come true. What should an HR leader do when you wake up to find your company with a ruined reputation, minimal financial capital, 53,000 employees on the payroll and more than 500 clients with pending deliverables worldwide. Where do you begin? The case illustrates a situation where immediate action is required to stop the tailspin into which the company was heading. Change management: The situation demanded that change be managed from a chaotic system to a stable system. The big issue though remains as to how one can get a system into a state of stability when everything is changing at the same time. Most change management plans have some stable variables, however in the case of Satyam there were multiple changes taking place simultaneously. A combination of change in leadership, client relationships, employee trust and confidence, market reactions together make for a perfect storm. Dealing with even one of these changes is a challenge for a company. In the case of Satyam, its entire existence was at stake. Communication: The demands for communicating effectively in a crisis situation are different than communicating under stable systems. The choice of medium, the speed of response, the content all need careful monitoring. Whereas most companies have teams that separately deal with internal and external communication, Satyam provides a unique situation where managing both effectively at the same time was critical to the future of the firm. The stakes for effective communication are much higher under the circumstances. This case can be used in organizational behaviour, human resources and corporate communications modules being taught to under-graduates, post-graduates and for executive education. Supplementary materials Teaching notes are available for educators only. Please contact your library to gain login details or email [email protected] to request teaching notes.

Integrity Management of Ground Movement Hazards

2016 ◽  
Author(s):  
Yong-Yi Wang ◽  
Don West ◽  
Douglas Dewar ◽  
Alex McKenzie-Johnson ◽  
Millan Sen
Keyword(s):  
Management Program ◽  
Ground Movement ◽  
Tensile Failure ◽  
Weld Strength ◽  
Factors Affecting ◽  
Ground Movements ◽  
Decision Points ◽  
Starting Point ◽  
Integrity Management ◽  
Girth Welds

Ground movements, such as landslides and subsidence/settlement, can pose serious threats to pipeline integrity. The consequence of these incidents can be severe. In the absence of systematic integrity management, preventing and predicting incidents related to ground movements can be difficult. A ground movement management program can reduce the potential of those incidents. Some basic concepts and terms relevant to the management of ground movement hazards are introduced first. A ground movement management program may involve a long segment of a pipeline that may have a threat of failure in unknown locations. Identifying such locations and understanding the potential magnitude of the ground movement is often the starting point of a management program. In other cases, management activities may start after an event is known to have occurred. A sample response process is shown to illustrate key considerations and decision points after the evidence of an event is discovered. Such a process can involve fitness-for-service (FFS) assessment when appropriate information is available. The framework and key elements of FFS assessment are explained, including safety factors on strain capacity. The use of FFS assessment is illustrated through the assessment of tensile failure mode. Assessment models are introduced, including key factors affecting the outcome of an assessment. The unique features of girth welds in vintage pipelines are highlighted because the management of such pipelines is a high priority in North America and perhaps in other parts of the worlds. Common practice and appropriate considerations in a pipeline replacement program in areas of potential ground movement are highlighted. It is advisable to replace pipes with pipes of similar strength and stiffness so the strains can be distributed as broadly as possible. The chemical composition of pipe steels and the mechanical properties of the pipes should be such that the possibility of HAZ softening and weld strength undermatching is minimized. In addition, the benefits and cost of using the workmanship flaw acceptance criteria of API 1104 or equivalent standards in making repair and cutout decisions of vintage pipelines should be evaluated against the possible use of FFS assessment procedures. FFS assessment provides a quantifiable performance target which is not available through the workmanship criteria. However, necessary inputs to perform FFS assessment may not be readily available. Ongoing work intended to address some of the gaps is briefly described.

scholarly journals The Comparison of Innovative Technology Usage Levels of Dairy Farms Supported and Non-Supported by IPARD Program; A Case Study of Konya

2018 ◽  
Vol 6 (12) ◽  
pp. 1809
Author(s):  
Aykut Örs ◽  
Cennet Oğuz
Keyword(s):  
Sampling Method ◽  
Dairy Farm ◽  
Dairy Farms ◽  
Point Of View ◽  
Innovative Technology ◽  
Technology Usage ◽  
Chi Square ◽  
Production Values ◽  
Usage Level ◽  
High Level

The purpose of this study is to compare innovative technology usage levels of dairy farms, supported and non-supported by The Instrument for Pre-accession Assistance-Rural Development (IPARD) program, by scoring their usage level of 10 innovative technologies in their dairy farms. Another purpose of the study is to determine the factors associated with the innovative technology usage levels of dairy farms. The main material of the study is dairy farms supported and not supported by the IPARD program in Konya. Full count sampling method was used when determining the dairy farms supported by IPARD Program and Neyman allocation sampling method was used when determining the dairy farm non-supported by IPARD program. Research data were collected from 50 dairy farms supported by IPARD program and 100 dairy farms non-supported by IPARD program by administering a questionnaire filled during the face-to-face interviews conducted with each individual respondent. As a result of the study, it was determined that the average gross production values and gross profits of dairy farms supported by IPARD program were 4 times higher than those non-supported by IPARD program. While innovative technology usage level of dairy farms non-supported by IPARD program were entirely low level, 90% of dairy farms supported by IPARD program were high level. From the point of view of dairy farm scale, it was determined that innovative technology usage levels were high (69.84%) in dairy farms that had 51 and more milking cows. As a result of chi-square independence test, statistically significant relationship was found between innovative technology usage level of dairy farm and 12 of 13 factors.

scholarly journals The influence on biogas production of three slurry-handling systems in dairy farms

2015 ◽  
Vol 46 (1) ◽  
pp. 30 ◽  
Author(s):  
Damiano Coppolecchia ◽  
Davide Gardoni ◽  
Cecilia Baldini ◽  
Federica Borgonovo ◽  
Marcella Guarino
Keyword(s):  
Organic Matter ◽  
Biogas Production ◽  
Dairy Farm ◽  
Dairy Farms ◽  
Organic Matter Concentration ◽  
Deep Pit ◽  
Volatile Solids ◽  
Methane Potential ◽  
Solid Liquid ◽  
Solid Liquid Separation

Handling systems can influence the production of biogas and methane from dairy farm manures. A comparative work performed in three different Italian dairy farms showed how the most common techniques (scraper, slatted floor, flushing) can change the characteristics of collected manure. Scraper appears to be the most <em>neutral</em> choice, as it does not significantly affect the original characteristics of manure. Slatted floor produces a manure that has a lower methane potential in comparison with scraper, due to: a lower content of volatile solids caused by the biodegradation occurring in the deep pit, and a lower specific biogas production caused by the change in the characteristics of organic matter. Flushing can produce three different fluxes: diluted flushed manure, solid separated manure and liquid separated manure. The diluted fraction appears to be unsuitable for conventional anaerobic digestion in completely stirred reactors (CSTR), since its content of organic matter is too low to be worthwhile. The liquid separated fraction could represent an interesting material, as it appears to accumulate the most biodegradable organic fraction, but not as primary substrate in CSTR as the organic matter concentration is too low. Finally, the solid-liquid separation process tends to accumulate inert matter in the solid separated fraction and, therefore, its specific methane production is low.

Immersed Membrane BioReactor (IMBR) for treatment of combined domestic and dairy wastewater in an isolated farm

2005 ◽  
Vol 51 (10) ◽  
pp. 327-334 ◽  
Author(s):  
A. Bick ◽  
J.G.P. Tuttle ◽  
S. Shandalov ◽  
G. Oron
Keyword(s):  
Membrane Bioreactor ◽  
Dairy Farm ◽  
Domestic Wastewater ◽  
High Strength ◽  
Dairy Farms ◽  
Pilot Scale ◽  
Dairy Wastewater ◽  
Transmembrane Pressure ◽  
Research Approach ◽  
Permeate Flux

In many regions dairy farms and milk processing industries discharge large quantities of their wastes to the surroundings posing serious environmental risks. This problem is mostly faced in small dairy farms and isolated communities lacking both central collection and conventional wastewater treatment systems. Dairy wastewater is characterized by high concentrations of organic matter, solids, nutrients, as well as fractions of dissolved inorganic pollutants, exceeding those levels considered typical for high strength domestic wastewaters. With the purpose of treating the combined dairy and domestic wastewater from a small dairy farm in the Negev Desert of Israel, the use of a recent emerging technology of Immersed Membrane BioReactor (IMBR) was evaluated over the course of 500 test hours, under a variety of wastewater feed quality conditions (during the test periods, the feed BOD5 ranged from 315 ppm up to 4,170 ppm). The overall performance of a pilot-scale Ultrafiltration (UF) IMBR process for a combined domestic and dairy wastewater was analyzed based on the Data Envelopment Analysis (DEA) method. The IMBR performance in terms of membrane performance (permeate flux, transmembrane pressure, and organic removal) and DEA model (Technical Efficiency) was acceptable. DEA is an empirically based methodology and the research approach has been found to be effective in the depiction and analysis for complex systems, where a large number of mutual interacting variables are involved.

scholarly journals Anthelmintic resistance to cattle gastrointestinal nematodes in selected dairy farms of Mymensingh and Sirajganj districts of Bangladesh

2018 ◽  
Vol 5 (1) ◽  
pp. 87-92 ◽  
Author(s):  
TM Mahibur Rahman ◽  
Anita Rani Dey ◽  
Saiful Islam ◽  
Md Shahadat Hossain ◽  
Md Hasanuzzaman Talukder ◽  
...  
Keyword(s):  
Anthelmintic Resistance ◽  
Dairy Farm ◽  
Dairy Farms ◽  
Treated Group ◽  
Gastrointestinal Nematodes ◽  
Control Group ◽  
The Status ◽  
Correction Table ◽  
Benzimidazole Anthelmintic ◽  
And Control

Correction: Table 1 and Table 2 have were omitted from the PDF in error. They were added to page 89 on 17th May 2018.Anthelmintic resistance (AR) to commonly used dewormers is one of the major world-wide constrain in livestock production. The present study was investigated the status of AR in BAU dairy farm, Mymensingh and Talukder dairy farm, Sirajganj. Faecal egg count reduction test (FECRT) was applied to assess AR in cattle of two dairy farms during January to June 2017. The anthelmintics tested were Albendazole (ABZ), a benzimidazole anthelmintic (Almex®, Square Ltd.) and Ivermectin (IVM) (Vermic®, Techno drugs Ltd.), administered at the doses recommended by the manufacturers. In each farm, cattle were divided into treatment and control (not treated) group based on faecal egg counts (FEC), that is at least 200 eggs/g. At 14 days after treatment, faecal samples were collected for post-treatment FEC, which is compared between treatment and control group. Resistance was defined if there was <95% reduction, with lower 95% confidence limit (CL) <90% in the FEC. AR was present in both the dairy farms involved in this study. The FECRT using ABZ revealed 79.7% (95% CL 87.9, 65.8) reduction and 95.8% (95% CL 98.7, 87.1) reduction of FEC in BAU and Talukder dairy farms, respectively. Also, FECRT using IVM revealed 77.9% (95% CL 97.7, 85.5) and 94.2% (95% CL 97.7, 85.5) reduction of FEC in BAU and Talukder dairy farms, respectively. Our study suggest that AR is present in both selected dairy farms and further extensive studies are required to determine the extent of AR in different cattle farms of Bangladesh.Res. Agric., Livest. Fish.5(1): 87-92, April 2018

scholarly journals Iodine content in bulk tank milk samples in relation to dairy farm size

2014 ◽  
Vol 83 (10) ◽  
pp. S9-S13 ◽  
Author(s):  
Lenka Vorlová ◽  
Lucia Hodulová ◽  
Ivana Borkovcová ◽  
Hana Přidalová ◽  
Romana Kostrhounová ◽  
...  
Keyword(s):  
Dairy Farm ◽  
Iodine Content ◽  
Dairy Farms ◽  
Raw Milk ◽  
Farm Size ◽  
Milk Samples ◽  
Significant Difference ◽  
Organic Dairy ◽  
Bulk Tank ◽  
Organic Dairy Farms

The aim of this study was to compare the iodine content in raw milk from organic and conventional dairy farms of different sizes. Milk samples were collected between 2012 and 2013, and the iodine content was determined by a Sandell-Kolthoff reaction after dry alkaline digestion of the milk samples. Comparing the iodine content in raw milk samples from small sized dairy farms (116.76 ± 46.29 μg/l) and large sized dairy farms (173.70 ± 35.42 μg/l), a significant difference in iodine content was observed (P ≤ 0.05). The lowest values were found in small and medium dairy farms, 45.30 μg/l and 40.46 μg/l, respectively. High variability (112.92 ± 94.74 μg/l) in the iodine content was detected in raw milk from medium sized dairy farms. When considering milk samples from organic dairy farms (119.29 μg /l ± 40.37) vs. conventional dairy farms (136.55 μg/l ± 42.91), no significant difference was detected. These results indicate higher iodine content in milk from large dairy farms regardless of conventional or organic farming methods.

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