Vincent Amanor-Boadu

Thermo-mechanical extrusion pretreatment for conversion of soybean hulls to fermentable sugars.

Thermo-mechanical extrusion pretreatment for lignocellulosic biomass was investigated using soybean hulls as the substrate. The enzyme cocktail used to hydrolyze pretreated soybean hulls to fermentable sugars was optimized using response surface methodology (RSM). Structural changes in substrate and sugar yields from thermo-mechanical processing were compared with two traditional pretreatment methods that utilized dilute acid (1% sulfuric acid) and alkali (1% sodium hydroxide). Extrusion processing parameters (barrel temperature, in-barrel moisture, screw speed) and processing aids (starch, ethylene glycol) were studied with respect to reducing sugar and glucose yields. The conditions resulting in the highest cellulose to glucose conversion (95%) were screw speed 350rpm, maximum barrel temperature 80°C and in-barrel moisture content 40%wb. Compared with untreated soybean hulls, glucose yield from enzymatic hydrolysis of soybean hulls increased by 69.6%, 128.7% and 132.2%, respectively, when pretreated with dilute acid, alkali and extrusion.

Sustainability of algae derived biodiesel: a mass balance approach.

A rigorous chemical engineering mass balance/unit operations approach is applied here to bio-diesel from algae mass culture. An equivalent of 50,000,000 gallons per year (0.006002 m3/s) of petroleum-based Number 2 fuel oil (US, diesel for compression-ignition engines, about 0.1% of annual US consumption) from oleaginous algae is the target. Methyl algaeate and ethyl algaeate diesel can according to this analysis conceptually be produced largely in a technologically sustainable way albeit at a lower available diesel yield. About 11 square miles of algae ponds would be needed with optimistic assumptions of 50 g biomass yield per day and m2 pond area. CO2 to foster algae growth should be supplied from a sustainable source such as a biomass-based ethanol production. Reliance on fossil-based CO2 from power plants or fertilizer production renders algae diesel non-sustainable in the long term.

Solar thermochemical production of ammonia from water, air and sunlight: Thermodynamic and economic analyses

Ammonia is an important input into agriculture and is used widely as base chemical for the chemical industry. It has recently been proposed as a sustainable transportation fuel and convenient one-way hydrogen carrier. Employing typical meteorological data for Palmdale, CA, solar energy is considered here as an inexpensive and renewable energy alternative in the synthesis of NH3 at ambient pressure and without natural gas. Thermodynamic process analysis shows that a molybdenum-based solar thermochemical NH3 production cycle, conducted at or below 1500 K, combined with solar thermochemical H2 production from water may operate at a net-efficiency ranging from 23 to 30% (lower heating value of NH3 relative to the total energy input). Net present value optimization indicates ecologically and economically sustainable NH3 synthesis at above about 160 tons NH3 per day, dependent primarily on heliostat costs (varied between 90 and 164 dollars/m2), NH3 yields (ranging from 13.9 mol% to stoichiometric conversion of fixed and reduced nitrogen to NH3), and the NH3 sales price. Economically feasible production at an optimum plant capacity near 900 tons NH3 per day is shown at relative conservative technical assumptions and at a reasonable NH3 sales price of about 534 ± 28 dollars per ton NH3.

Contract Selectivity, Food Safety, and Traceability

Contracts are an increasingly common method for coordinating exchange in the food industry. Contracts often include specifications for product attributes including food safety. One of the goals of explicit safety specifications is to discourage or deter suppliers who would deliver unsafe food. In this article, we use a principal-agent model in the context of adverse selection to examine how contracts that include traceability can be used to select against producers who cannot meet a processors safety specifications. We find that the motivation to select against unsafe producers depends on the magnitude of the failure costs and the proportion of the failure costs allocated to producers. We also identify the conditions under which the processor selects against unsafe producers regardless of traceability. Our results are important to regulators and negotiators who want to support safe producers and deter unsafe producers.

Traceability, Moral Hazard, and Food Safety

Errors in traceability can significantly impact the moral hazard associated with producing safe food. The effect of moral hazard depends on the proportion of unsafe food costs that can be allocated to the responsible producer, which depends on the efficiency of the traceability system. In this paper, we develop a model that identifies the minimum level of traceability needed to mitigate moral hazard and motivate suppliers to produce safe food. Regulators and consumer can use the results of this research to design regulations and contracts that mitigate moral hazard and motivate producers to deliver safe food.

Does Women’s Empowerment in Agriculture Matter for Children’s Health Status? Insights from Northern Ghana

Given that women in rural communities in developing countries are responsible for the nutrition and health-related decisions affecting children in their care, their empowerment may influence the health status of their children. The association between women’s empowerment, measured by using a recently developed Women’s Empowerment in Agriculture Index, and children’s health status is examined for a sample of households in Northern Ghana applying a Multiple Indicators Multiple Causes (MIMIC) model. The MIMIC approach is used to link multiple indicator variables with multiple independent variables through a “single underlying” latent variable. Height-for-age and weight-for-height z-scores are used as indicators of the underlying children’s health status and women’s empowerment in agriculture and control variables are used as the multiple independent variables. Our results show that neither the composite empowerment score used to capture women’s empowerment in agriculture nor its decomposed components are statistically significant in their association with the latent children’s health status. However, the associations between children’s health status and control variables such as mother’s education, child’s age, household’s hunger scale and residence locale are statistically significant. Results also confirm the existence of the ‘single underlying’ common latent variable. Of the two health status indicators, height-for-age scores and weight-for- height scores, the former exhibited a relatively stronger association with the latent health status. While promoting women’s empowerment to enhance their ability to make strategic life choices, it is important to carefully consider how the achievement of these objectives will impact the women’s well-being and the well-being of the children in their care.

The determinants of household-level well-being in Northern Ghana

ABSTRACT Empirical analysis of the physical well-being at the household level was conducted for a sample of households in Northern Ghana using a Multiple Indicators Multiple Causes model. Physical well-being was indicated by the number of stunted children, number of wasted children, and number of underweight women. Results suggest that well-being at the household level is indeed represented by the latent variable and can be conceptualized in much the same way as the well-being of the individuals who constitute the household. Results show that the literacy of father and the number of dependents are associated with the largest shift in the underlying household’s physical well-being. Locale and the household assets were also significantly associated with the collective underlying latent variable. The variability in household physical well-being is explained more by the number of stunted children in the household than any of the other indicators of household well-being.

Countervailing and Antidumping Actions: An Evaluation of Canada's Experience with the United States

Introduction As is well known, Canada and the U.S. are each others principal trading partners. Between 1980 and 1988, the average annual total value of trade in all goods and services (imports plus exports) between Canada and the U.S. averaged

Bio-butanol vs. bio-ethanol: A technical and economic assessment for corn and switchgrass fermented by yeast or Clostridium acetobutylicum

103 billion per year. As a result of the 1989 Canada-U.S. Trade Agreement (CUFTA), the total trade between the two countries had reached

Do Inspection and Traceability Provide Incentives for Food Safety

290 billion by 1996. Canadas total trade with the rest of the world amounted to less than 29 percent of its total trade with the U.S. alone between 1989 and 1996. This indicates the importance of the smooth movement of goods and services between the two countries and, as well, Canadas particular dependence on this trading relationship. With reference to agrifood trade, the situation is not different from the trade in all goods and services. For example, U.S. total agrifood trade with Canada accounted for more than 17 percent of all its agrifood trade, while total Canadian agrifood trade with the U.S. averaged about 52 percent over the 1989 to 1996 period. Thus, this trade is of key importance for each country. Given this, any trade disruptions between Canada and the U.S. represent a significant cost to businesses in the two countries. An overriding objective of international trade laws is to ensure that exporting nations do not obtain unfair advantage over domestic producers in importing countries. Therefore, most countries have developed their laws to ensure that the trade environment is fair and operates to enhance the value that consumers receive from traded goods and services. A review of the important components of U.S. and Canadian trade laws indicates some significant differences between the letter of the law in each country. It is important to note that the differences do not end with the letter but go also to the spirit and enforcement of the laws. These differences have subjected U.S.-Canada trade disputes to considerable academic analysis over the past two decades, as supported by the number and variety of papers and articles written on the subject (van Duren and Martin 1989; Martin 1991; Lermer and Klein 1990). The two major types of trade dispute that have received the most attention and, certainly, have been used most by the U.S. against Canada are countervailing duties and antidumping actions. While significant work has been done on these, there is a need to revisit the issues within the framework of the emerging rules on dispute settlement mechanisms under multilateral trade agreements such as the North American Free Trade Agreement (NAFTA) and the World Trade Organization (WTO) (Meilke and van Duren 1990; Schmitz and Sigurdson 1990). This paper, therefore, proceeds with two objectives in mind: first, to evaluate Canadas experience with the U.S. with respect to countervail and antidumping cases over the years to determine their impact on trade relations between the two countries and, second, to assess the contribution of NAFTA and WTO to the improvement of trade dispute settlement between Canada and the U.S. Two methods have been used here: a review of the trade literature, focusing on the economic synthesis of trade disputes, and an analysis of the agrifood-related trade disputes brought by the U.S. against Canada, focusing on countervail and antidumping cases. In addition, we present a brief explanation of the salient characteristics of countervail and antidumping under U.S. trade remedy laws and, in the section following that, we look at some examples of agrifood countervail and antidumping cases brought by the U.S. against Canada from the early 1980s and their resulting decisions. The paper concludes with a review of the changes introduced into international trade disputes by the GATT/WTO dispute settlement mechanisms and their implications on the certainty of trade and cost to business and industries. Antidumping under U.S. Trade Remedy Laws In a competitive market, international product prices are technically established by adding the cost of production of the product to the transportation cost involved in exporting the product, plus all additional charges such as duties and excise taxes. …